2005
Seki, K; Fujii, T; Handa, Y
Change of H wave and MEP during pedalling by one leg Inproceedings
In: Sawan, M (Ed.): pp. 063, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: Gait & Posture
@inproceedings{IFESS2005_063,
title = {Change of H wave and MEP during pedalling by one leg},
author = {K Seki and T Fujii and Y Handa},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_063_Seki.pdf},
year = {2005},
date = {2005-07-01},
pages = {063},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {H wave and motor evoked potential (MEP) induced by trancranial magnetic stimulation in one leg was recorded during pedaling movement by contralateral leg in the healthy subjects and hemiplegic stroke patients. In the healthy subjects the amplitude of H wave was decreased and MEP was increased during pedaling. In the stroke patients H wave did not change but MEP appeared during pedaling though it was absent during rest. Pedaling by one leg can modulate the function of spinal motor neuron by activating motor control system in the brain.},
keywords = {Gait & Posture},
pubstate = {published},
tppubtype = {inproceedings}
}
H wave and motor evoked potential (MEP) induced by trancranial magnetic stimulation in one leg was recorded during pedaling movement by contralateral leg in the healthy subjects and hemiplegic stroke patients. In the healthy subjects the amplitude of H wave was decreased and MEP was increased during pedaling. In the stroke patients H wave did not change but MEP appeared during pedaling though it was absent during rest. Pedaling by one leg can modulate the function of spinal motor neuron by activating motor control system in the brain.
Chou, L W; Binder-Macleod, S A
Changes in the relationship between stimulation intensity and force output with fatigue for human quadriceps muscles Inproceedings
In: Sawan, M (Ed.): pp. 066, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: Gait & Posture
@inproceedings{IFESS2005_066,
title = {Changes in the relationship between stimulation intensity and force output with fatigue for human quadriceps muscles},
author = {L W Chou and S A Binder-Macleod},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_066_Chou.pdf},
year = {2005},
date = {2005-07-01},
pages = {066},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {Functional movements often require repetitive activation of muscles. Muscle fatigue causes the decline in force output and may result in inability of the muscle to produce sufficient forces to allow continued performance. Clinically, stimulation intensity is increased to overcome the decline in force due to muscle fatigue during FES. The precise control of muscle force is needed to maximize performance and minimize fatigue during FES; however, changes in the human skeletal muscle force-intensity relationship with fatigue have not been previously reported. The purpose of this study is to investigate the changes in the force-intensity relationship with fatigue. Right quadriceps muscles of 9 healthy adults were tested isometrically. Pre- and post-fatigue force responses to 60-Hz stimulation trains at different pulse durations were recorded and analyzed. Our results showed an exponential relationship between force output and stimulation pulse duration and that the normalized force-intensity relationship did not change with fatigue. Thus, although the force-intensity relationship is dynamic, the fact that the normalized force-intensity relationship did not change with fatigue can help clinicians identify appropriate stimulation intensity to precise control muscle force during the application of FES.},
keywords = {Gait & Posture},
pubstate = {published},
tppubtype = {inproceedings}
}
Functional movements often require repetitive activation of muscles. Muscle fatigue causes the decline in force output and may result in inability of the muscle to produce sufficient forces to allow continued performance. Clinically, stimulation intensity is increased to overcome the decline in force due to muscle fatigue during FES. The precise control of muscle force is needed to maximize performance and minimize fatigue during FES; however, changes in the human skeletal muscle force-intensity relationship with fatigue have not been previously reported. The purpose of this study is to investigate the changes in the force-intensity relationship with fatigue. Right quadriceps muscles of 9 healthy adults were tested isometrically. Pre- and post-fatigue force responses to 60-Hz stimulation trains at different pulse durations were recorded and analyzed. Our results showed an exponential relationship between force output and stimulation pulse duration and that the normalized force-intensity relationship did not change with fatigue. Thus, although the force-intensity relationship is dynamic, the fact that the normalized force-intensity relationship did not change with fatigue can help clinicians identify appropriate stimulation intensity to precise control muscle force during the application of FES.
Matsunaga, T; Shimada, Y; Sato, M; Chida, S; Hatakeyama, K; Itoi, E; Misawa, A; Aizawa, T; Iwami, T; Nakamura, M; Miyawaki, K; Iizuka, K
Computer simulation model of FES assisted swing-through gait Inproceedings
In: Sawan, M (Ed.): pp. 068, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: Gait & Posture
@inproceedings{IFESS2005_068,
title = {Computer simulation model of FES assisted swing-through gait},
author = {T Matsunaga and Y Shimada and M Sato and S Chida and K Hatakeyama and E Itoi and A Misawa and T Aizawa and T Iwami and M Nakamura and K Miyawaki and K Iizuka},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_068_Matsunaga.pdf},
year = {2005},
date = {2005-07-01},
pages = {068},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {Objectives: To evaluate a kinematics of swing-through gait with free-knnes in non-disabled individuals and to simulate FES assisted swing-through gait. Methods: Twelve non-disabled adult males participated in this study. Joint angles and ground reaction forces were investigated during the swing-through gait with Lofstland crutches. Dynamic muscloskeletal model was developed to simulate the FES assisted swing-through gait in complete paraplegics with free-knees. Results: The mean maximum flexion and extension angle of the hip joint were 42.6 textpm 10.5 degrees (Mean textpm SD) and -11.7 textpm 8.9 degrees. The mean maximum flexion and extension angle of the knee joint were 44.8 textpm 9.0 degrees and -12.6 textpm 7.5 degrees. The mean maximum flexion and extension angle of the ankle joint were 6.7 textpm 10.5 degrees and 11.1 textpm 13.7 degrees. The dynamic muscloskeletal model was successfully controlled. Conclusion: The kinematic data were applied in the simulation models for the swing-through gait in complete paraplegics with free-knees.},
keywords = {Gait & Posture},
pubstate = {published},
tppubtype = {inproceedings}
}
Objectives: To evaluate a kinematics of swing-through gait with free-knnes in non-disabled individuals and to simulate FES assisted swing-through gait. Methods: Twelve non-disabled adult males participated in this study. Joint angles and ground reaction forces were investigated during the swing-through gait with Lofstland crutches. Dynamic muscloskeletal model was developed to simulate the FES assisted swing-through gait in complete paraplegics with free-knees. Results: The mean maximum flexion and extension angle of the hip joint were 42.6 textpm 10.5 degrees (Mean textpm SD) and -11.7 textpm 8.9 degrees. The mean maximum flexion and extension angle of the knee joint were 44.8 textpm 9.0 degrees and -12.6 textpm 7.5 degrees. The mean maximum flexion and extension angle of the ankle joint were 6.7 textpm 10.5 degrees and 11.1 textpm 13.7 degrees. The dynamic muscloskeletal model was successfully controlled. Conclusion: The kinematic data were applied in the simulation models for the swing-through gait in complete paraplegics with free-knees.
Lee, J Y; Lee, Y H; Kim, S Y; Kim, Y J; Kim, K A Y H
Effect of Dermatomal Electrical stimulation on Hemiplegic Drop foot During Gait in Patients with Stroke Inproceedings
In: Sawan, M (Ed.): pp. 060, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: Gait & Posture
@inproceedings{IFESS2005_060,
title = {Effect of Dermatomal Electrical stimulation on Hemiplegic Drop foot During Gait in Patients with Stroke},
author = {J Y Lee and Y H Lee and S Y Kim and Y J Kim and K A Y H Kim},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_060_Lee.pdf},
year = {2005},
date = {2005-07-01},
pages = {060},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {The purpose of this study was in hemiplegia patients, to examine the effect of the inhibitory effect of spasticity appeared in response to dermatomal electrostimulation applied to the ankle plantar flexor on the spastic foot drop during gaits. The study population was 9 patients. They walked for 5 times before electrical stimulation and during electrical stimulation. In the gait performed under dermatomal electrical stimulation, in the affected side, the ankle dorsiflexion angle during the initial heel contact was significantly increased and during the midstance, the maximal dorsiflexion angle of ankle joint was found to be significantly increased (p < 0.05). In addition, prior to electrical stimulation and during the stimulation, between the non-affected side and the affected side, the time difference of swing time was decreased, however, a statistically significant difference was not detected (p > 0.05). The experiment results show that in spastic foot drop patients caused by the spacticity of the ankle plantar flexor muscles, dermatomal electrical simulation increased the active range of motion of the ankle joint and affected the gait cycle and the gait pattern},
keywords = {Gait & Posture},
pubstate = {published},
tppubtype = {inproceedings}
}
The purpose of this study was in hemiplegia patients, to examine the effect of the inhibitory effect of spasticity appeared in response to dermatomal electrostimulation applied to the ankle plantar flexor on the spastic foot drop during gaits. The study population was 9 patients. They walked for 5 times before electrical stimulation and during electrical stimulation. In the gait performed under dermatomal electrical stimulation, in the affected side, the ankle dorsiflexion angle during the initial heel contact was significantly increased and during the midstance, the maximal dorsiflexion angle of ankle joint was found to be significantly increased (p < 0.05). In addition, prior to electrical stimulation and during the stimulation, between the non-affected side and the affected side, the time difference of swing time was decreased, however, a statistically significant difference was not detected (p > 0.05). The experiment results show that in spastic foot drop patients caused by the spacticity of the ankle plantar flexor muscles, dermatomal electrical simulation increased the active range of motion of the ankle joint and affected the gait cycle and the gait pattern
Akamatsu, C; Seki, K; Fujii, T; Xu, R; Handa, Y
Effects of manual acupuncture on reflexes in the legs: modulation of soleus H-reflexes and motor evoked potentials Inproceedings
In: Sawan, M (Ed.): pp. 071, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: Gait & Posture
@inproceedings{IFESS2005_071,
title = {Effects of manual acupuncture on reflexes in the legs: modulation of soleus H-reflexes and motor evoked potentials},
author = {C Akamatsu and K Seki and T Fujii and R Xu and Y Handa},
editor = {M Sawan},
url = {none},
year = {2005},
date = {2005-07-01},
pages = {071},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {none},
keywords = {Gait & Posture},
pubstate = {published},
tppubtype = {inproceedings}
}
none
Sachs, N A; Chang, E L; Vyas, N; Weiland, J D
Electrical Stimulation of the Paralyzed Orbicularis Oculi Inproceedings
In: Sawan, M (Ed.): pp. 054, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: Gait & Posture
@inproceedings{IFESS2005_054,
title = {Electrical Stimulation of the Paralyzed Orbicularis Oculi},
author = {N A Sachs and E L Chang and N Vyas and J D Weiland},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_054_Sachs.pdf},
year = {2005},
date = {2005-07-01},
pages = {054},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {Electrical stimulation of the orbicularis oculi muscle was performed at 1 and 4 weeks after induced paralysis of the 7th cranial nerve, as well as in normal rabbit. Strength-duration curves for muscle twitch demonstrated chronaxie values of 0.439 textpm 0.023ms (mean textpm SD) in normal (N = 2), 56.4 textpm 7.5ms after one week of paralysis (N = 2) and 24.1 textpm 0.6ms after four weeks of paralysis (N = 2). In addition, percent closure was measured for biphasic pulses ranging from 0.5ms to 100ms per phase and biphasic pulse trains ranging from 0.5ms to 10ms per phase delivered at 50Hz. Normal rabbit demonstrated the greatest degree of closure, followed by rabbits with 1 week of paralysis and 4 weeks of paralysis for nearly all sets of stimulation parameters. Both normal rabbit and rabbit with 1 week of paralysis achieved greater than 80% closure with a train of 5 consecutive 10ms pulses, while rabbit with 4 weeks of paralysis achieved a maximum of 71.5 textpm 9.2% closure for the same stimulation parameters.},
keywords = {Gait & Posture},
pubstate = {published},
tppubtype = {inproceedings}
}
Electrical stimulation of the orbicularis oculi muscle was performed at 1 and 4 weeks after induced paralysis of the 7th cranial nerve, as well as in normal rabbit. Strength-duration curves for muscle twitch demonstrated chronaxie values of 0.439 textpm 0.023ms (mean textpm SD) in normal (N = 2), 56.4 textpm 7.5ms after one week of paralysis (N = 2) and 24.1 textpm 0.6ms after four weeks of paralysis (N = 2). In addition, percent closure was measured for biphasic pulses ranging from 0.5ms to 100ms per phase and biphasic pulse trains ranging from 0.5ms to 10ms per phase delivered at 50Hz. Normal rabbit demonstrated the greatest degree of closure, followed by rabbits with 1 week of paralysis and 4 weeks of paralysis for nearly all sets of stimulation parameters. Both normal rabbit and rabbit with 1 week of paralysis achieved greater than 80% closure with a train of 5 consecutive 10ms pulses, while rabbit with 4 weeks of paralysis achieved a maximum of 71.5 textpm 9.2% closure for the same stimulation parameters.
Bijak, M; Rakos, M; Hofer, C; Moedlin, M; Strohhofer, M; Raschka, D; Kern, H; Mayr, W
From the wheelchair to walking with the aid of an eight channel stimulation system: a case study Inproceedings
In: Sawan, M (Ed.): pp. 067, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: Gait & Posture
@inproceedings{IFESS2005_067,
title = {From the wheelchair to walking with the aid of an eight channel stimulation system: a case study},
author = {M Bijak and M Rakos and C Hofer and M Moedlin and M Strohhofer and D Raschka and H Kern and W Mayr},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_067_Bijak.pdf},
year = {2005},
date = {2005-07-01},
pages = {067},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {Functional Electrical Stimulation (FES) is useable to restore in part the lost leg function of paraplegic patients. For this purpose an eight channel stimulation system was developed to activate via standard hydrogel surface electrodes quadriceps and gluteus muscles, peroneal reflex and either adductor muscles or any other muscle group according to patients individual needs. In the scope of a clinical trial ten paraplegic patients were trained to achieve standing up and walking by means of FES. This paper describes the rehabilitation process of one subject from the beginning to FES supported walking over a distance of 5 meters.},
keywords = {Gait & Posture},
pubstate = {published},
tppubtype = {inproceedings}
}
Functional Electrical Stimulation (FES) is useable to restore in part the lost leg function of paraplegic patients. For this purpose an eight channel stimulation system was developed to activate via standard hydrogel surface electrodes quadriceps and gluteus muscles, peroneal reflex and either adductor muscles or any other muscle group according to patients individual needs. In the scope of a clinical trial ten paraplegic patients were trained to achieve standing up and walking by means of FES. This paper describes the rehabilitation process of one subject from the beginning to FES supported walking over a distance of 5 meters.
Popovic, D B; Popovic, M B; Schwirtlich, L; Grey, M; Mazzaro, N; Sinkjaer, T
Functional Electrical Therapy of Walking: Pilot Study Inproceedings
In: Sawan, M (Ed.): pp. 072, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: Gait & Posture
@inproceedings{IFESS2005_072,
title = {Functional Electrical Therapy of Walking: Pilot Study},
author = {D B Popovic and M B Popovic and L Schwirtlich and M Grey and N Mazzaro and T Sinkjaer},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_072_Popovic.pdf},
year = {2005},
date = {2005-07-01},
pages = {072},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {The Functional Electrical Therapy (FET) in this study was a 4-week, 30 minutes daily walking exercise assisted with multi-channel electrical stimulation in acute post-stroke hemiplegic subjects. The FET used three channels of muscle stimulation to enhance the stance phase, push-off, and swing of the paretic leg. The timing of the stimulation was programmed to match the volitional, life-like sequences of muscle activities. We analyzed the speed and symmetry between the paretic and nonparetic legs in the FET group (5 subjects) and Control group (5 subjects), who received sham stimulation during the walking sessions. The maximum walking speed increased from 0.2 to 0.8 m/s in the FET group, and 0.25 to 0.68 m/s in the Control group, and the symmetry index decreased for about 10 % in the FET group and 6 % in the Control group. These results call for large randomized clinical trial.},
keywords = {Gait & Posture},
pubstate = {published},
tppubtype = {inproceedings}
}
The Functional Electrical Therapy (FET) in this study was a 4-week, 30 minutes daily walking exercise assisted with multi-channel electrical stimulation in acute post-stroke hemiplegic subjects. The FET used three channels of muscle stimulation to enhance the stance phase, push-off, and swing of the paretic leg. The timing of the stimulation was programmed to match the volitional, life-like sequences of muscle activities. We analyzed the speed and symmetry between the paretic and nonparetic legs in the FET group (5 subjects) and Control group (5 subjects), who received sham stimulation during the walking sessions. The maximum walking speed increased from 0.2 to 0.8 m/s in the FET group, and 0.25 to 0.68 m/s in the Control group, and the symmetry index decreased for about 10 % in the FET group and 6 % in the Control group. These results call for large randomized clinical trial.
Massoud, R; Tokhi, M O; Gharooni, C S; Huq, M S
Fuzzy Logic Control of Cyclical Leg Motion Inproceedings
In: Sawan, M (Ed.): pp. 058, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: Gait & Posture
@inproceedings{IFESS2005_058,
title = {Fuzzy Logic Control of Cyclical Leg Motion},
author = {R Massoud and M O Tokhi and C S Gharooni and M S Huq},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_058_Massoud.pdf},
year = {2005},
date = {2005-07-01},
pages = {058},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {The aim of this paper is to investigate modelling and control of paraplegic leg cyclical motion. A humanoid leg is developed in Visual Nastran software in the setting position, and used with Matlab/Simulink to develop a fuzzy logic control (FLC) strategy to control the knee joint movement. The FLC output is the FES stimulation signal which stimulates the knee extensors providing torque to the knee joint. The control of such a plant (leg with knee extensors) is a complex task as only the knee extensors are stimulated to extent the knee and then the knee is left freely to flex in the flexion period. FLC shows effectiveness in controlling especially in the absence of mathematical model for the plant. This control strategy can also be used for functional cyclical exercises such as ergometry cycling and rowing. Simulation results verifying the control strategy are presented and discussed. Two types of knee joint functional movements are investigated and the tracking performance is satisfactory.},
keywords = {Gait & Posture},
pubstate = {published},
tppubtype = {inproceedings}
}
The aim of this paper is to investigate modelling and control of paraplegic leg cyclical motion. A humanoid leg is developed in Visual Nastran software in the setting position, and used with Matlab/Simulink to develop a fuzzy logic control (FLC) strategy to control the knee joint movement. The FLC output is the FES stimulation signal which stimulates the knee extensors providing torque to the knee joint. The control of such a plant (leg with knee extensors) is a complex task as only the knee extensors are stimulated to extent the knee and then the knee is left freely to flex in the flexion period. FLC shows effectiveness in controlling especially in the absence of mathematical model for the plant. This control strategy can also be used for functional cyclical exercises such as ergometry cycling and rowing. Simulation results verifying the control strategy are presented and discussed. Two types of knee joint functional movements are investigated and the tracking performance is satisfactory.
Preuss, R; Stein, R B; Fung, J
Gait kinematics after forty weeks of use of the Walkaide 2 : a case study Inproceedings
In: Sawan, M (Ed.): pp. 059, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: Gait & Posture
@inproceedings{IFESS2005_059,
title = {Gait kinematics after forty weeks of use of the Walkaide 2 : a case study},
author = {R Preuss and R B Stein and J Fung},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_059_Preuss.pdf},
year = {2005},
date = {2005-07-01},
pages = {059},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {Functional electrical stimulation (FES) of the common peroneal (CP) nerve is known to have positive orthotic effects for patients with a dropped foot. The Walkaide2 (WA2) is a battery-operated, single channel electrical device that senses the orientation of the leg and stimulates the CP nerve at different phases of the gait cycle. This case study investigates the effects, both orthotic and therapeutic, of 40 weeks of daily use of the WA2 on the kinematics of gait of a 59 y.o. male with a dropped foot following a stroke. Kinematic variables were measured during walking, both with and without the WA2, at 4 separate sessions (following 0, 4, 12 and 40 weeks of use) using a 6-camera Vicon 512 motion analysis system. As expected, an increase in the range of dorsiflexion was observed at the affected ankle with the WA2. More importantly, over the 40 weeks of use, an increase in dorsiflexion was noted even when the subject walked without the WA2. Within the limits of a single-subject design, these results support the therapeutic and orthotic efficacy of FES, with respect to gait kinematics, from prolonged use with the WA2.},
keywords = {Gait & Posture},
pubstate = {published},
tppubtype = {inproceedings}
}
Functional electrical stimulation (FES) of the common peroneal (CP) nerve is known to have positive orthotic effects for patients with a dropped foot. The Walkaide2 (WA2) is a battery-operated, single channel electrical device that senses the orientation of the leg and stimulates the CP nerve at different phases of the gait cycle. This case study investigates the effects, both orthotic and therapeutic, of 40 weeks of daily use of the WA2 on the kinematics of gait of a 59 y.o. male with a dropped foot following a stroke. Kinematic variables were measured during walking, both with and without the WA2, at 4 separate sessions (following 0, 4, 12 and 40 weeks of use) using a 6-camera Vicon 512 motion analysis system. As expected, an increase in the range of dorsiflexion was observed at the affected ankle with the WA2. More importantly, over the 40 weeks of use, an increase in dorsiflexion was noted even when the subject walked without the WA2. Within the limits of a single-subject design, these results support the therapeutic and orthotic efficacy of FES, with respect to gait kinematics, from prolonged use with the WA2.
Huq, M S; Alam, M S; Gharooni, S; Tokhi, M O
Genetic Optimization of Spring Brake Orthosis Parameters: Spring Propertie Inproceedings
In: Sawan, M (Ed.): pp. 070, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: Gait & Posture
@inproceedings{IFESS2005_070,
title = {Genetic Optimization of Spring Brake Orthosis Parameters: Spring Propertie},
author = {M S Huq and M S Alam and S Gharooni and M O Tokhi},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_070_Huq.pdf},
year = {2005},
date = {2005-07-01},
pages = {070},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {Spring Brake Orthosis (SBO) [1] generates the swing phase of gait by employing a spring at the knee joint to store energy during the knee extension through quadriceps stimulation, which is then released to produce knee flexion. The spring characteristics in this case would be the only optimizable parameters determining the resultant knee flexion trajectory. In this work, subject specific optimum spring parameters (spring constant, spring rest angle) for SBO purposes are obtained using Genetic Algorithms (GAs). Both linear and nonlinear types of spring are tested. The Mean Square Error (MSE) between the reference and actual trajectory is defined as the cost function. It turns out that linear spring could perform better than nonlinear spring in SBO.},
keywords = {Gait & Posture},
pubstate = {published},
tppubtype = {inproceedings}
}
Spring Brake Orthosis (SBO) [1] generates the swing phase of gait by employing a spring at the knee joint to store energy during the knee extension through quadriceps stimulation, which is then released to produce knee flexion. The spring characteristics in this case would be the only optimizable parameters determining the resultant knee flexion trajectory. In this work, subject specific optimum spring parameters (spring constant, spring rest angle) for SBO purposes are obtained using Genetic Algorithms (GAs). Both linear and nonlinear types of spring are tested. The Mean Square Error (MSE) between the reference and actual trajectory is defined as the cost function. It turns out that linear spring could perform better than nonlinear spring in SBO.
Kim, J; Mills, J K; Popovic, M R
Inverse Dynamics Solutions of Arm-Free Standing for Paraplegics Inproceedings
In: Sawan, M (Ed.): pp. 073, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: Gait & Posture
@inproceedings{IFESS2005_073,
title = {Inverse Dynamics Solutions of Arm-Free Standing for Paraplegics},
author = {J Kim and J K Mills and M R Popovic},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_073_Kim.pdf},
year = {2005},
date = {2005-07-01},
pages = {073},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {In this paper, an application of the dynamics and control of redundant robotic systems is presented in order to investigate the feasibility of functional electrical stimulation assisted arm-free standing for paraplegics. Through the inverse dynamics analysis of a three dimensional dynamic model of quiet standing, several sets of the minimum number of degrees of freedom (DOF) such that there are unique torque inputs that generate desired kinematic outputs of the model were found. In addition, it was demonstrated that the proposed nonlinear dynamic model could achieve asymptotic stability with only six DOF out of twelve DOF, assuming the remaining six DOF are not actuated. Two controllers, proportional and derivative plus gravity compensation scheme and the computed torque control were proposed. Stability analysis and simulation results suggested that the dynamic redundancy of the biological bipedal stance system allows the selection of an ideal subset of DOF in a particular patient to design a neuroprosthesis for standing.},
keywords = {Gait & Posture},
pubstate = {published},
tppubtype = {inproceedings}
}
In this paper, an application of the dynamics and control of redundant robotic systems is presented in order to investigate the feasibility of functional electrical stimulation assisted arm-free standing for paraplegics. Through the inverse dynamics analysis of a three dimensional dynamic model of quiet standing, several sets of the minimum number of degrees of freedom (DOF) such that there are unique torque inputs that generate desired kinematic outputs of the model were found. In addition, it was demonstrated that the proposed nonlinear dynamic model could achieve asymptotic stability with only six DOF out of twelve DOF, assuming the remaining six DOF are not actuated. Two controllers, proportional and derivative plus gravity compensation scheme and the computed torque control were proposed. Stability analysis and simulation results suggested that the dynamic redundancy of the biological bipedal stance system allows the selection of an ideal subset of DOF in a particular patient to design a neuroprosthesis for standing.
Burridge, J H; Haugland, M; Larsen, B; Svaneholm, N; Iversen, H; P., Brogger-Christensen; Pickering, R; Sinkjaer, T
Long-term follow-up of patients using the ActiGait implanted drop-foot stimulator Inproceedings
In: Sawan, M (Ed.): pp. 065, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: Gait & Posture
@inproceedings{IFESS2005_065,
title = {Long-term follow-up of patients using the ActiGait implanted drop-foot stimulator},
author = {J H Burridge and M Haugland and B Larsen and N Svaneholm and H Iversen and Brogger-Christensen P. and R Pickering and T Sinkjaer},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_065_Burridge.pdf},
year = {2005},
date = {2005-07-01},
pages = {065},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {The ActiGait(R) drop foot stimulator has been shown to be an effective and safe device for the treatment of drop foot following stroke, showing comparable results with surface drop foot systems [1,2]. The device comprises an implant, a control unit and a wireless heel switch that triggers stimulation. Stimulation of the common Peroneal (CP) nerve is through a nerve cuff placed around the CP nerve just above the knee. The cuff has four tri-polar electrodes, orientated to activate different nerve fibres within the CP nerve. Each channel is programmed independently via a PC. Fifteen patients who had suffered a stroke at least six months prior to recruitment were implanted with the ActiGait(R) drop-foot stimulator. Two subjects deviated from the study protocol and, at the 90 day assessment three subjects had technical problems. Fifteen months after the start of the study 13 subjects using the device have undergone a further assessment in which we repeated the walking tests with and without the stimulator. Results showed a statistically significant improvement in walking parameters when stimulation was applied. Mean increase in distance walked = 11.5m p=0.05 and increase in maximum walking speed 0.07 m/s p=0.01. Statistically significant improvements were also detected when walking parameters were compared with those at Baseline. In conclusion: when initial technical problems with the ActiGait implanted drop-foot stimulator were overcome the system was shown to be effective in improving walking and well accepted by users.},
keywords = {Gait & Posture},
pubstate = {published},
tppubtype = {inproceedings}
}
The ActiGait(R) drop foot stimulator has been shown to be an effective and safe device for the treatment of drop foot following stroke, showing comparable results with surface drop foot systems [1,2]. The device comprises an implant, a control unit and a wireless heel switch that triggers stimulation. Stimulation of the common Peroneal (CP) nerve is through a nerve cuff placed around the CP nerve just above the knee. The cuff has four tri-polar electrodes, orientated to activate different nerve fibres within the CP nerve. Each channel is programmed independently via a PC. Fifteen patients who had suffered a stroke at least six months prior to recruitment were implanted with the ActiGait(R) drop-foot stimulator. Two subjects deviated from the study protocol and, at the 90 day assessment three subjects had technical problems. Fifteen months after the start of the study 13 subjects using the device have undergone a further assessment in which we repeated the walking tests with and without the stimulator. Results showed a statistically significant improvement in walking parameters when stimulation was applied. Mean increase in distance walked = 11.5m p=0.05 and increase in maximum walking speed 0.07 m/s p=0.01. Statistically significant improvements were also detected when walking parameters were compared with those at Baseline. In conclusion: when initial technical problems with the ActiGait implanted drop-foot stimulator were overcome the system was shown to be effective in improving walking and well accepted by users.
Szecsi, J; Krause, P; Krafczyk, S; Fiegel, M; Straube, A
Modeling the activity of daily life -relevant functional output of FES cycling: an experimental study Inproceedings
In: Sawan, M (Ed.): pp. 064, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: Gait & Posture
@inproceedings{IFESS2005_064,
title = {Modeling the activity of daily life -relevant functional output of FES cycling: an experimental study},
author = {J Szecsi and P Krause and S Krafczyk and M Fiegel and A Straube},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_064_Szecsi.pdf},
year = {2005},
date = {2005-07-01},
pages = {064},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {Purpose: This study expands on connections between laboratory measurements and "in field" performance of persons with complete spinal cord injury (SCI). It explores whether a regression model incorporating the conditional abilities, muscle force and endurance limit, can predict the distance that untrained SCI individuals can cover during outdoor FES cycling. Methods: One trained and six untrained subjects with complete SCI participated. Isometric moment profiles of the six stimulated muscle groups were determined with a special setup that measured torque. Endurance was measured during FES-propelled ergometer exercise tests. Covered distance and cadence data were collected during outdoor FES-cycling tests. Subsequently, local muscular fatigue was computed from measured torques, cadences, and endurance limits. Finally, the relationship between fatigue rate and distance covered until subject exhaustion was measured by correlation and regression analysis. Results: The correlation analysis of cycling distance yielded highly significant determination coefficients of 0.92 for fatigue resistance and 0.86 for cycling capability (p<0.01). Conclusion: Since the determination coefficient for the correlation of isometric torque and distance amounted to 0.74 (p<0.01), inclusion of the endurance limit in the regression model of distance(as defined by fatigue resistance or cycling capability) reduces the unexplained rest variance by 0.92-0.74=0.18 and 0.86-0.74=0.12, respectively. Thus, a composite score for muscle fatigue rate including force and endurance describes the cycling performance of untrained SCI subjects better than a score including only force, because both force and endurance are independent determinants of FES cycling.},
keywords = {Gait & Posture},
pubstate = {published},
tppubtype = {inproceedings}
}
Purpose: This study expands on connections between laboratory measurements and "in field" performance of persons with complete spinal cord injury (SCI). It explores whether a regression model incorporating the conditional abilities, muscle force and endurance limit, can predict the distance that untrained SCI individuals can cover during outdoor FES cycling. Methods: One trained and six untrained subjects with complete SCI participated. Isometric moment profiles of the six stimulated muscle groups were determined with a special setup that measured torque. Endurance was measured during FES-propelled ergometer exercise tests. Covered distance and cadence data were collected during outdoor FES-cycling tests. Subsequently, local muscular fatigue was computed from measured torques, cadences, and endurance limits. Finally, the relationship between fatigue rate and distance covered until subject exhaustion was measured by correlation and regression analysis. Results: The correlation analysis of cycling distance yielded highly significant determination coefficients of 0.92 for fatigue resistance and 0.86 for cycling capability (p<0.01). Conclusion: Since the determination coefficient for the correlation of isometric torque and distance amounted to 0.74 (p<0.01), inclusion of the endurance limit in the regression model of distance(as defined by fatigue resistance or cycling capability) reduces the unexplained rest variance by 0.92-0.74=0.18 and 0.86-0.74=0.12, respectively. Thus, a composite score for muscle fatigue rate including force and endurance describes the cycling performance of untrained SCI subjects better than a score including only force, because both force and endurance are independent determinants of FES cycling.
Lagerquist, O; Klakowicz, P M; Baldwin, E R L; Collins, D F
M-wave and H-reflex amplitude increases during tetanic stimulation over triceps surae muscles Inproceedings
In: Sawan, M (Ed.): pp. 076, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: Gait & Posture
@inproceedings{IFESS2005_076,
title = {M-wave and H-reflex amplitude increases during tetanic stimulation over triceps surae muscles},
author = {O Lagerquist and P M Klakowicz and E R L Baldwin and D F Collins},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_076_Lagerquist.pdf},
year = {2005},
date = {2005-07-01},
pages = {076},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {High-frequency stimulation (100 Hz, 1 ms pulse width) delivered over triceps surae and tibialis anterior muscles (muscle stimulation) can evoke contractions "extra" to those due to stimulating motor axons directly. These extra contractions are thought to arise from central mechanisms (Collins et al., 2001). Stimulation of the tibial nerve in the popliteal fossa (nerve stimulation) produces similar contractions and these are associated with increased amplitudes of H-reflexes, but not of M-waves. The present aim was to deliver muscle stimulation to evoke extra contractions and assess changes in Mwave and H-reflex amplitudes. Muscle stimulation was applied over the right triceps surae muscles (20-100-20 Hz for 2-3-2 s, respectively) while recording isometric plantarflexion torque and surface soleus EMG. In 4/10 subjects the stimulus artifact was sufficiently small to eanlabe an accurate measurement of changes in amplitudes of soleus M-waves, H-reflexes, and torque during 20-Hz stimulation. Data were compared between 1 (1s) and 6 (6s) seconds after the onset of stimulation (i.e.1 s before to 2 s after the 100 Hz burst). For these four subjects, torque increased by 213% (p = 0.01 )between 1 and 6s. Amplitudes of M-waves increased by 63% (p = 0.03) and H-reflexes by 249% (p = 0.05) over the same interval. After the 100 Hz burst M-waves were 5-20 times larger than the concurrent H-reflexes. Contrary to tibial nerve stimulation, during muscle stimulation not only H-reflex but also M-wave amplitude increased after the 100 Hz stimulation. The data suggest that different mechanisms contribute to the extra contractions evoked during nerve versus muscle stimulation.},
keywords = {Gait & Posture},
pubstate = {published},
tppubtype = {inproceedings}
}
High-frequency stimulation (100 Hz, 1 ms pulse width) delivered over triceps surae and tibialis anterior muscles (muscle stimulation) can evoke contractions "extra" to those due to stimulating motor axons directly. These extra contractions are thought to arise from central mechanisms (Collins et al., 2001). Stimulation of the tibial nerve in the popliteal fossa (nerve stimulation) produces similar contractions and these are associated with increased amplitudes of H-reflexes, but not of M-waves. The present aim was to deliver muscle stimulation to evoke extra contractions and assess changes in Mwave and H-reflex amplitudes. Muscle stimulation was applied over the right triceps surae muscles (20-100-20 Hz for 2-3-2 s, respectively) while recording isometric plantarflexion torque and surface soleus EMG. In 4/10 subjects the stimulus artifact was sufficiently small to eanlabe an accurate measurement of changes in amplitudes of soleus M-waves, H-reflexes, and torque during 20-Hz stimulation. Data were compared between 1 (1s) and 6 (6s) seconds after the onset of stimulation (i.e.1 s before to 2 s after the 100 Hz burst). For these four subjects, torque increased by 213% (p = 0.01 )between 1 and 6s. Amplitudes of M-waves increased by 63% (p = 0.03) and H-reflexes by 249% (p = 0.05) over the same interval. After the 100 Hz burst M-waves were 5-20 times larger than the concurrent H-reflexes. Contrary to tibial nerve stimulation, during muscle stimulation not only H-reflex but also M-wave amplitude increased after the 100 Hz stimulation. The data suggest that different mechanisms contribute to the extra contractions evoked during nerve versus muscle stimulation.
Maimouna, B; Gingras, D; Bedard, S; Langlois, D
A New Method Combining Wavelet Analysis and RBI for Gait Phases Detection in ENG Signals Inproceedings
In: Sawan, M (Ed.): pp. 069, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: Gait & Posture
@inproceedings{IFESS2005_069,
title = {A New Method Combining Wavelet Analysis and RBI for Gait Phases Detection in ENG Signals},
author = {B Maimouna and D Gingras and S Bedard and D Langlois},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_069_Maimouna.pdf},
year = {2005},
date = {2005-07-01},
pages = {069},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {In this article, a new method that combines a discrete wavelet transform with the RBI method to process cat gait ENG signals is introduced. The method proved to be very efficient in segmentation of the signal into phases, especially in faulty cycles, and can reveal up to five gait phases within a cycle.},
keywords = {Gait & Posture},
pubstate = {published},
tppubtype = {inproceedings}
}
In this article, a new method that combines a discrete wavelet transform with the RBI method to process cat gait ENG signals is introduced. The method proved to be very efficient in segmentation of the signal into phases, especially in faulty cycles, and can reveal up to five gait phases within a cycle.
Cikajlo, I; Obreza, P; Savrin, R; Matja, Z; Bajd, T
Postural Balance Improvement Using Dermatome Electrical Stimulation Therapy in Incomplete SCI Patients Inproceedings
In: Sawan, M (Ed.): pp. 061, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: Gait & Posture
@inproceedings{IFESS2005_061,
title = {Postural Balance Improvement Using Dermatome Electrical Stimulation Therapy in Incomplete SCI Patients},
author = {I Cikajlo and P Obreza and R Savrin and Z Matja and T Bajd},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_061_Cikajlo.pdf},
year = {2005},
date = {2005-07-01},
pages = {061},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {The objective of the study was to quantify and evaluate the effectiveness of dermatome electrical stimulation on postural balancing. Artificially induced perturbations in eight different directions were provided to the person standing in the modified BalanceTrainer. Simultaneously electromyograms (EMG) of selected muscle groups (tibialis anterior, soleus, tensor fasciae latae and quadriceps) were recorded while an incomplete SCI subject (Th 3-5) was standing on two force platforms before and after 20 min. of L3-4 dermatome stimulation therapy. Decrease of quadriceps spasticity and improved postural responses were noticed.},
keywords = {Gait & Posture},
pubstate = {published},
tppubtype = {inproceedings}
}
The objective of the study was to quantify and evaluate the effectiveness of dermatome electrical stimulation on postural balancing. Artificially induced perturbations in eight different directions were provided to the person standing in the modified BalanceTrainer. Simultaneously electromyograms (EMG) of selected muscle groups (tibialis anterior, soleus, tensor fasciae latae and quadriceps) were recorded while an incomplete SCI subject (Th 3-5) was standing on two force platforms before and after 20 min. of L3-4 dermatome stimulation therapy. Decrease of quadriceps spasticity and improved postural responses were noticed.
Ferrante, S; Saunders, B; Duffell, L; Pedrocchi, A; Hunt, K; Perkins, T; Donaldson, N
Quantitative evaluation of stimulation strategies for FES cycling Inproceedings
In: Sawan, M (Ed.): pp. 074, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: Gait & Posture
@inproceedings{IFESS2005_074,
title = {Quantitative evaluation of stimulation strategies for FES cycling},
author = {S Ferrante and B Saunders and L Duffell and A Pedrocchi and K Hunt and T Perkins and N Donaldson},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_074_Ferrante.pdf},
year = {2005},
date = {2005-07-01},
pages = {074},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {The purpose of this work is to evaluate the stimulation patterns used to produce cycling by functional electrical stimulation. Specific experiments were carried out on two SCI patients using a motor to keep a constant cadence. We stimulated one muscle at a time for the whole cycle and measured the torque produced at the crank. We evaluated the contributions of the muscles to the movement to identify the ranges of useful functionality, i.e., the positive torque. The peak torques were also identified. This way we propose an experimental-based method to distinguish when the stimulation of each muscle facilitates or hinders the cycling movement and at what angles the muscles provide the most functionality. The results were compared to currently implemented patterns and it was shown that these patterns are perhaps not making the most use of the muscle-crank angle relationship.},
keywords = {Gait & Posture},
pubstate = {published},
tppubtype = {inproceedings}
}
The purpose of this work is to evaluate the stimulation patterns used to produce cycling by functional electrical stimulation. Specific experiments were carried out on two SCI patients using a motor to keep a constant cadence. We stimulated one muscle at a time for the whole cycle and measured the torque produced at the crank. We evaluated the contributions of the muscles to the movement to identify the ranges of useful functionality, i.e., the positive torque. The peak torques were also identified. This way we propose an experimental-based method to distinguish when the stimulation of each muscle facilitates or hinders the cycling movement and at what angles the muscles provide the most functionality. The results were compared to currently implemented patterns and it was shown that these patterns are perhaps not making the most use of the muscle-crank angle relationship.
Johnston, T E; Stackhouse, C A; Smith, B T; Betz, R R
Reciprocal versus swing-through gait using implanted functional electrical stimulation in motor complete SCI. A case report Inproceedings
In: Sawan, M (Ed.): pp. 055, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: Gait & Posture
@inproceedings{IFESS2005_055,
title = {Reciprocal versus swing-through gait using implanted functional electrical stimulation in motor complete SCI. A case report},
author = {T E Johnston and C A Stackhouse and B T Smith and R R Betz},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_055_Johnston.pdf},
year = {2005},
date = {2005-07-01},
pages = {055},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {Most of the studies on lower extremity functional electrical stimulation focus on the use of a reciprocal gait pattern. However, a swing-through pattern is another option. The purpose of this study was to compare a reciprocal and a swing-through gait pattern using an implanted FES system with 18 lower extremity channels in a young man with a thoracic spinal cord injury. After training, the subject underwent instrumented gait analysis using both patterns, and the results showed that the subject could walk faster and take larger steps when using a swing-through pattern as compared to a reciprocal pattern. The subject also reported preferring the swing- through pattern as it was faster. Due to the subject's preference for the swing-through gait pattern, less emphasis was placed on the reciprocal gait pattern during training. Therefore, further training and altering of patterns of muscle stimulation may have allowed the subject to walk faster with a reciprocal pattern.},
keywords = {Gait & Posture},
pubstate = {published},
tppubtype = {inproceedings}
}
Most of the studies on lower extremity functional electrical stimulation focus on the use of a reciprocal gait pattern. However, a swing-through pattern is another option. The purpose of this study was to compare a reciprocal and a swing-through gait pattern using an implanted FES system with 18 lower extremity channels in a young man with a thoracic spinal cord injury. After training, the subject underwent instrumented gait analysis using both patterns, and the results showed that the subject could walk faster and take larger steps when using a swing-through pattern as compared to a reciprocal pattern. The subject also reported preferring the swing- through pattern as it was faster. Due to the subject's preference for the swing-through gait pattern, less emphasis was placed on the reciprocal gait pattern during training. Therefore, further training and altering of patterns of muscle stimulation may have allowed the subject to walk faster with a reciprocal pattern.
Collins, D F; Brown, A M; Burke, D; Gorman, R. B. amd
Reflex-like contributions to contractions evoked by stimulation over the human triceps surae during sitting and standing Inproceedings
In: Sawan, M (Ed.): pp. 075, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: Gait & Posture
@inproceedings{IFESS2005_075,
title = {Reflex-like contributions to contractions evoked by stimulation over the human triceps surae during sitting and standing},
author = {D F Collins and A M Brown and D Burke and R.B.amd Gorman},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_075_Collins.pdf},
year = {2005},
date = {2005-07-01},
pages = {075},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {Electrical stimulation delivered over the triceps surae of relaxed, seated, human subjects can generate contractions that arise in part via reflex pathways through the spinal cord. Such synaptic recruitment of motoneurons may be useful for FES. The present experiments compare the magnitude of this reflex-like contribution between sitting and standing. Eight able-bodied subjects participated. Stimulation (1 ms pulses) was delivered in 2 triangular patterns (~10-100-10 Hz in 2 or 6 s) with subjects in 3 positions; 1. seated, knees bent (~900), 2. seated knees straight and 3. standing. Ankle torque and EMG were recorded. To assess the reflex contribution, comparisons were made between the torque 0.5 s after stimulus onset (Time 1) and that 0.5 s from the end of the stimulus train (Time 2). Both triangular patterns of stimulation resulted in significantly more torque at Time 2 than Time 1 for all three positions. However, there was no significant difference in the reflex contribution (Time 2/Time 1) between any of the three positions. On average across the 3 positions the 2 and 6 s stimuli generated 4 and 18 times more torque at T2 than T1. These reflex-like contractions may be useful for FES assisted standing and walking.},
keywords = {Gait & Posture},
pubstate = {published},
tppubtype = {inproceedings}
}
Electrical stimulation delivered over the triceps surae of relaxed, seated, human subjects can generate contractions that arise in part via reflex pathways through the spinal cord. Such synaptic recruitment of motoneurons may be useful for FES. The present experiments compare the magnitude of this reflex-like contribution between sitting and standing. Eight able-bodied subjects participated. Stimulation (1 ms pulses) was delivered in 2 triangular patterns (~10-100-10 Hz in 2 or 6 s) with subjects in 3 positions; 1. seated, knees bent (~900), 2. seated knees straight and 3. standing. Ankle torque and EMG were recorded. To assess the reflex contribution, comparisons were made between the torque 0.5 s after stimulus onset (Time 1) and that 0.5 s from the end of the stimulus train (Time 2). Both triangular patterns of stimulation resulted in significantly more torque at Time 2 than Time 1 for all three positions. However, there was no significant difference in the reflex contribution (Time 2/Time 1) between any of the three positions. On average across the 3 positions the 2 and 6 s stimuli generated 4 and 18 times more torque at T2 than T1. These reflex-like contractions may be useful for FES assisted standing and walking.
Trumbower, R D; Faghri, P D
In: Sawan, M (Ed.): pp. 056, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: Gait & Posture
@inproceedings{IFESS2005_056,
title = {Relationship between isometric pedal force generation and stimulation intensity of individual leg muscles involved in FES-induced leg cycling},
author = {R D Trumbower and P D Faghri},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_056_Trumbower.pdf},
year = {2005},
date = {2005-07-01},
pages = {056},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {Optimizing power transfer from stimulated muscles during functional electrical stimulation leg cycle ergometry (FES-LCE) and maximizing forward acceleration of the crank during cycling may increase the efficiency of this system for exercise. A better understanding of individual muscles'force generation and their relationship to the intensity of stimulation would help with this optimization. This study evaluated the orthogonal pedal force generations of quadriceps, hamstrings, gluteus, gastrocnemius, and tibialis muscles during three different stimulation intensities (70mA, 105mA, and 140mA) at eight fixed crank positions of an FES-LCE. Seven healthy male individuals with spinal cord injury participated. Significant differences in pedal forces were found between stimulation intensities and crank positions (p<0.05). Pedal forces for each muscle were significantly different between FES intensities of 70mA and 140mA with no differences at 105mA and 140mA. There was a high correlation (r=.936) in the direction and force generated for gastrocnemius and tibialis, as well as hamstrings and gastrocnemius (r=.895) across all crank positions. In conclusion, lowering the stimulation intensity during cycling and sequencing the activation of thigh and leg muscles within a closed-loop system may improve pedal effectiveness and reduce fatigue possibly due to over stimulation.},
keywords = {Gait & Posture},
pubstate = {published},
tppubtype = {inproceedings}
}
Optimizing power transfer from stimulated muscles during functional electrical stimulation leg cycle ergometry (FES-LCE) and maximizing forward acceleration of the crank during cycling may increase the efficiency of this system for exercise. A better understanding of individual muscles'force generation and their relationship to the intensity of stimulation would help with this optimization. This study evaluated the orthogonal pedal force generations of quadriceps, hamstrings, gluteus, gastrocnemius, and tibialis muscles during three different stimulation intensities (70mA, 105mA, and 140mA) at eight fixed crank positions of an FES-LCE. Seven healthy male individuals with spinal cord injury participated. Significant differences in pedal forces were found between stimulation intensities and crank positions (p<0.05). Pedal forces for each muscle were significantly different between FES intensities of 70mA and 140mA with no differences at 105mA and 140mA. There was a high correlation (r=.936) in the direction and force generated for gastrocnemius and tibialis, as well as hamstrings and gastrocnemius (r=.895) across all crank positions. In conclusion, lowering the stimulation intensity during cycling and sequencing the activation of thigh and leg muscles within a closed-loop system may improve pedal effectiveness and reduce fatigue possibly due to over stimulation.
Faghri, P D; Trumbower, R D
Short-duration FES-induced leg cycling dynamics at different stimulation intensities and flywheel resistances Inproceedings
In: Sawan, M (Ed.): pp. 057, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: Gait & Posture
@inproceedings{IFESS2005_057,
title = {Short-duration FES-induced leg cycling dynamics at different stimulation intensities and flywheel resistances},
author = {P D Faghri and R D Trumbower},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_057_Faghri.pdf},
year = {2005},
date = {2005-07-01},
pages = {057},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {This study investigated the peak crank power output production during different flywheel resistances and stimulation intensities and their relationship to fatigue rate during short duration functional electrical stimulation leg cycle ergometry (FES-LCE). Six healthy individuals with spinal cord injury (SCI) participated in this study. Subjects pedalled at different maximum allowable stimulation intensities of 70, 105, and 140mA and flywheel resistances of 0/8th, 1/8th, and 2/8th kilopond. The results showed that peak power production was significantly different between three stimulation intensities for each flywheel resistances (p<0.05). Mean cycling cadences were also significantly different between three stimulation intensities and flywheel resistances (p<0.05). A fatigue index was formulated based on changes in peak crank power output levels during cycling and compared between testing conditions. The level of fatigue was strongly related to flywheel resistance and stimulation intensity (p<0.01). The higher fatigue indexes were noted at higher flywheel resistance and during lower stimulation intensities. These finding suggest that to minimize fatigue rate and to optimize power output during steady-state cycling, increases in stimulation intensity is required. However the current maximum stimulation intensity of 140mA may not be essential in maintaining constant pedalling speed at higher flywheel resistances.},
keywords = {Gait & Posture},
pubstate = {published},
tppubtype = {inproceedings}
}
This study investigated the peak crank power output production during different flywheel resistances and stimulation intensities and their relationship to fatigue rate during short duration functional electrical stimulation leg cycle ergometry (FES-LCE). Six healthy individuals with spinal cord injury (SCI) participated in this study. Subjects pedalled at different maximum allowable stimulation intensities of 70, 105, and 140mA and flywheel resistances of 0/8th, 1/8th, and 2/8th kilopond. The results showed that peak power production was significantly different between three stimulation intensities for each flywheel resistances (p<0.05). Mean cycling cadences were also significantly different between three stimulation intensities and flywheel resistances (p<0.05). A fatigue index was formulated based on changes in peak crank power output levels during cycling and compared between testing conditions. The level of fatigue was strongly related to flywheel resistance and stimulation intensity (p<0.01). The higher fatigue indexes were noted at higher flywheel resistance and during lower stimulation intensities. These finding suggest that to minimize fatigue rate and to optimize power output during steady-state cycling, increases in stimulation intensity is required. However the current maximum stimulation intensity of 140mA may not be essential in maintaining constant pedalling speed at higher flywheel resistances.
Schiefer, M A; Gustafson, K J; Triolo, R J; Durand, D M; Tyler, D J
Standing Neuroprosthetics: Modeling Selective Stimulation with a FINE Inproceedings
In: Sawan, M (Ed.): pp. 062, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: Gait & Posture
@inproceedings{IFESS2005_062,
title = {Standing Neuroprosthetics: Modeling Selective Stimulation with a FINE},
author = {M A Schiefer and K J Gustafson and R J Triolo and D M Durand and D J Tyler},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_062_Schiefer.pdf},
year = {2005},
date = {2005-07-01},
pages = {062},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {The long-term goal of this research is to restore standing function through selective activation of target fascicles in the femoral nerve by a flat interface nerve electrode (FINE). The optimal number and location of contacts in a FINE had not been determined previously. A realistic three-dimensional finite element model based on a cross section of human femoral nerve and FINE is presented. Simulated voltages are applied as an extracellular field to the MRG double-cable axon model. Initial simulations indicate that optimal contacts may exist for each fascicular group. Further, nerve reshaping improves selectivity by 26%. Models indicate the FINE can be used for selective muscle activation in standing neuroprosthetics.},
keywords = {Gait & Posture},
pubstate = {published},
tppubtype = {inproceedings}
}
The long-term goal of this research is to restore standing function through selective activation of target fascicles in the femoral nerve by a flat interface nerve electrode (FINE). The optimal number and location of contacts in a FINE had not been determined previously. A realistic three-dimensional finite element model based on a cross section of human femoral nerve and FINE is presented. Simulated voltages are applied as an extracellular field to the MRG double-cable axon model. Initial simulations indicate that optimal contacts may exist for each fascicular group. Further, nerve reshaping improves selectivity by 26%. Models indicate the FINE can be used for selective muscle activation in standing neuroprosthetics.