Dynamic simulation analysis on gait features of hemiplegic patients / 医用生物力学

Objective To study the intrinsic relationship between hemiplegic gait features and abnormal muscle strength of lower limbs,so as to elucidate the muscle strength causes of hemiplegic gait and provide recommendations for its clinical treatment.Methods Models of hemiplegic gait and normal gait were established for simulation,and the validity of the models was verified by comparing the simulation model with measured data of the normal gait.The differences in kinetic data,ground reaction force (GRF) and muscle force between the two models were analyzed to explore the different dynamic characteristic of hemiplegic gait and normal gait.Results The complex correlation coefficient between LifeMOD simulation results and measured data was 0.922,indicating that the established dynamic model was reasonable and effective.Hemiplegic patient with low tibialis anterior muscle strength led to ankle dorsiflexion inadequacy during initial ground period,and low gastrocnemius muscle could not achieve the promoting effect from ground during preswing period.Conclusions The strength weakness of tibialis anterior muscle and gastrocnemius are the main reasons for foot drooping and other hemiplegic gait characteristics.LifeMOD modeling and simulation can assist the diagnosis of abnormal muscle strength in hemiplegia patients.

Dynamic simulation analysis on gait features of hemiplegic patients / 医用生物力学

Objective To study the intrinsic relationship between hemiplegic gait features and abnormal muscle strength of lower limbs, so as to elucidate the muscle strength causes of hemiplegic gait and provide recommendations for its clinical treatment. Methods Models of hemiplegic gait and normal gait were established for simulation, and the validity of the models was verified by comparing the simulation model with measured data of the normal gait. The differences in kinetic data, ground reaction force (GRF) and muscle force between the two models were analyzed to explore the different dynamic characteristic of hemiplegic gait and normal gait. Results The complex correlation coefficient between LifeMOD simulation results and measured data was 0.922, indicating that the established dynamic model was reasonable and effective. Hemiplegic patient with low tibialis anterior muscle strength led to ankle dorsiflexion inadequacy during initial ground period, and low gastrocnemius muscle could not achieve the promoting effect from ground during preswing period. Conclusions The strength weakness of tibialis anterior muscle and gastrocnemius are the main reasons for foot drooping and other hemiplegic gait characteristics. LifeMOD modeling and simulation can assist the diagnosis of abnormal muscle strength in hemiplegia patients.

Application of Surface Electromyography in Abnormal Gait Analysis for Stroke (review) / 中国康复理论与实践

The abnormal gait after stroke was mainly related to the decreasing strength with increasing tension of paretic lower limb muscles. Surface electromyography (sEMG) can respond to the neuromuscular function, that is valuable for abnormal gait analysis for stroke patients. This paper mainly introduced the anatomical basis with sEMG features of walking, the performance of abnormal gait and ab-normal gait analysis based on sEMG. It focused on the advances of sEMG in the analysis of temporal patterns and activating characteristics of muscles associated with abnormal gait, as well as abnormal gait pattern.

A new elastic suspension strap orthosis for stroke patients to improve their walking ability in the early stage of recovery / 中华物理医学与康复杂志

Objective To explore the efficacy of a new elastic suspension strap orthosis, designed by the authors, in improving the motor function and walking ability of stroke patients. Methods Thirty-nine stroke pa-tients less than 1 month after stroke were recruited and divided randomly into a treatment group and a control group. The patients in the treatment group accepted walking training with the assistance of an elastic suspension strap orthosis, 5 times a week for 8 weeks, while the control group accepted the same training without the assistance of the elastic suspension strap orthosis. Results The treatment group improved significantly more than the control group with regard to its average Fugl-Meyer score, the functional ambulation categories of its members, and their walking speeds. Conclusions The elastic suspension strap orthosis could help correct abnormal gait patterns, improve walking speed, and enhance the recovery of walking ability in stroke patients.

The Effects of Shoe Lifts to the Unaffected Limb on Gait Pattern in Hemiplegic Stroke Patients

OBJECTIVE: To evaluate the effects of shoe lift to the unaffected limb on hemiplegic gait after stroke. METHOD: Three dimensional gait analysis was performed in 20 chronic hemiplegic patients with shoe lifts (5, 10, 15 mm) to the unaffected limb. The order of experimental series was randomized among subjects. Temporal gait parameters were measured and compared according to the height of shoe lifts in the affected and unaffected limbs. RESULTS: The stride time of both limbs and step time of the affected limb were decreased, and stride length of both limbs and step length of unaffected limb were increased after shoe lift apply (p<0.05). Thus walking velocity and cadence were increased. In gait cycle, there was decreased double limb support phase of affected limb (p<0.05). These improvement of gait patterns of hemiplegics was maximum after shoe lift of 10 mm height. CONCLUSION: Weight bearing with shoe lift may contribute to improved postural control and gait performance in hemiplegics. Furthermore, the study about long-term effects of shoe lifts to the unaffected limb may be necessary.

The Development of Ankle Control Elastic Band for Improvement in Walking of Hemiplegic Patients

OBJECTIVE: The aims of this study were to verify that the newly developed ankle control elastic band (ACE band) can improve the gait pattern of hemiplegic patients by assessment of objective and subjective data. METHOD: ACE band consisted of medial ring, lateral ring, and elastic band was devised and 11 ambulatory stroke patients were evaluated with gait measurements, functional ambulation categories (FAC), functional reach test (FRT), and questionnaires for the effect of ACE band. Gait measurements were of 10 m walking time, cadence, stride length, stride period, stance phase, single support time, and single support time asymmetry ratio. RESULTS: Gait measurements with the ACE band showed significant improvement (p<0.05 or p<0.01). FAC and FRT with the ACE band were significantly increased (p<0.01), and the questionnaires suggested that wearing the ACE band helped improve toe dragging, swinging leg forward, taking weight through foot, confidence of gait, safety of gait, gait distance and gait velocity. CONCLUSION: ACE band was invented for improvement of hemiplegic gait, and its evaluation of gait measurements, FAC, FRT, and questionnaire showed that the ACE band was effective for hemiplegic gait after stroke.

Evaluation of Standing Balance in Hemiplegic Patients Using the Functional Reach Test

OBJECTIVE: To examine the validity of the fuctional reach test (FRT) for evaluation of standing balance in hemiplegic patients. METHOD: Twenty three hemiplegic patients who were capable of standing without assistive devices were assessed on the FRT only with intact upper limb, the one-legged stance, the timed up and go test (TUG), the 10 meter walking time (10 mWT), the 'Hauser' ambulation index (AI), and the standing balance of Bohannon. RESULTS: The forward reach of FRT demonstrated significant correlation with the TUG and the 10 mWT (p<0.01), but no significant relationship with the one-legged stance, standing balance of Bohannon and AI. CONCLUSION: The forward reach of FRT may be simple and useful tool for assessing the clinical balance function and reflecting gait ability and fall-down risk in hemiplegic patients.

Effect of Rhythmic Stimulation of Music on Hemiplegic Gait

OBJECTIVE: We used music as a rhythmic cue in gait training of patients with hemiplegia and analysed its effect on gait parameters. METHOD: Twenty hemiplegic patients were included in the study. Gait cycle, foot contact area, and center of pressure pathway were measured by F-scan with and without music. Four subjects were followed after 3 weeks of gait training using rhythmic cue with music. RESULTS: 1) In involved limb, stance phase was slightly increased from 65.8+/-9.9% to 67.8+/-7.9%, and single limb support was changed from 17.1+/-6.3% to 17.2+/-6.2%, without statistical significance. 2) Stance and swing symmetry was slightly increased from 0.77+/-0.13 and 0.52+/-0.21 to 0.83+/-0.09 and 0.54+/-0.16 respectively, without statistical significance. 3) Foot contact area and anteroposterior distance of center of pressure were not changed significantly. 4) All 4 subjects who were followed after 3 weeks showed increased single limb support of involved limb (from 14.5% to 18.8%) and swing symmetry (from 0.47 to 0.67). CONCLUSION: Though it was not proved to be effective for every hemiplegics, use of rhythmic cue with music in gait training may be helpful in some patients. Further study is needed to confirm these results.

Comparison of Gait Analysis and Energy Consumption between Various Types of Plastic Ankle Foot Orthoses in Hemiplegic Patients

OBJECTIVE: The purpose of this study were to investigate the temporospatial, kinematic data and energy consumption in hemiplegic patients according to the types of ankle-foot orthosis (AFO), and to determine the most effective type of AFO for gait training. METHOD: A prospective study was performed for 10 patients with hemiplegia who was able to walk independently at indoor level. The temporospatial, kinematic data and energy consumption were compared in each five different conditions: 1) barefoot, 2) donning AFO with posterior leaf spring (PLS), 3) donning PLS with the distal part of metatarsal head trimmed off (PLS-C), 4) donning hinged PLS (HPLS), 5) donning hinged PLS with the distal part of metatarsal head trimmed off (HPLS-C). RESULTS: With four types of PLS, maximal ankle plantar flexion was significantly decreased, however we didn't find any difference in kinematic data of the pelvis and hip as compared with barefoot and with PLS, HPLS, HPLS-C and maximal knee extension angle was significantly decreased compared with barefoot. With HPLS-C, cadence and walking speed significantly increased and double support time and oxygen cost significantly decreased as compared with barefoot. CONCLUSION: This study showed increased walking speed, decreased energy cost and improvedgait pattern after donning HPLS-C especially in hemiplegic patients. So HPLS-C may be effective in hemiplegic patients for gait training.

The Effects of Shoes Modification on Energy Consumption in Hemiplegic Gait

OBJECTIVE: To evaluate the effect of a contralateral shoe-lift and ipsilateral leather outsole on the energy consumption in hemiplegic gait. METHOD: Ten hemiplegic patients who could walk independently were enrolled. Using portable ergospirometer (K4b2, Cosmed, Italy), quantitative evaluation of oxygen consumption under varying shoes conditions was done: 1) regular shoes 2) a half-inch shoe-lift on the sound side 3) a half-inch shoe-lift on the sound side and leather outsole on the plegic side. The evaluation distance was 20 meter on comfortable walking speed. RESULTS: The oxygen consumption was significantly decreased after the application of shoe-lift compared with regular shoes (p<0.01), and the oxygen consumption was least with the application of shoe-lift and leather outsole (p<0.05). This effect was prominent in subject with poor muscle power in hemiplegic lower extremity. The walking speed was also increased with shoe-lift and leather outsole (p<0.05). CONCLUSION: The results of this study demonstrate that proper shoes modification can reduce the energy consumption in hemiplegic gait and can lead to more efficient functional ambulation.

Effect of Plastic Ankle Foot Orthosis and Functional Electrical Stimulation on Hemiplegic Gait

OBJECTIVE: To investigate the changes of gait patterns in hemiplegic patients with ankle foot orthosis (AFO) and with functional electrical stimulation (FES). METHOD: Fifteen hemiplegic patients who can walk independently with cane participated in this study. Kinematic gait analysis was performed for all subjects using three-dimensional gait analysis system in barefoot, wearing AFO, and applying FES. The mean values of each gait trials were taken and statistically analysed by repeated measures of ANOVA. RESULTS: Genu recurvatum at stance phase and excessive ankle plantar flexion at stance and swing phase were decreased after wearing AFO. Excessive ankle plantar flexion at swing phase were decreased after applying FES. CONCLUSION: The results showed that the FES is useful for the correction of hemiplegic gait as mush as of wearing AFO.

Analysis of the Stance Phase in a Hemiplegic Patient by the Measurement of Plantar Pressure

OBJECTS: The purpose of this study is to estimate the values of foot pressure of the stance phase during a gait cycle in hemiplegic gait. METHOD: Thirty patients who had a stroke and forty healthy adults were evaluated by the EMED-SF system to analyze the stance phase of hemiplegic gait. The stance phase was evaluated by 6 points according to the foot pressure and center of pressure proposed by Lee et al.2) RESULTS: 1) In hemiplegics, the stance time of involved limb decreased compared with that of the uninvolved limb and increased that of control groups (p<0.05). 2) In hemiplegics, the midstance time increased but the loading response and terminal stance decreased compared with the uninvolved limb and controls (p<0.05). 3) In hemiplegics, the midstance time decreased and the loading response and terminal phase increased according to the increased Brunnstrom stage (p<0.05). CONCLUSION: The results showed that an analysis of stance phase by the measurement of plantar pressure was a valuable parameter in the gait analysis of hemiplegic patients.

Effect of Ankle Foot Orthosis on Hemiplegic Gait

Hemiplegic gait is characterized by slow and poorly coordinated movements of the affected limb resulting from foot drop or equinus deformities. Ankle-foot orthoses(AFO) are frequently prescribed to improve the gait pattern of hemiplegics. Plastic AFO with different trimlines in controlling ankle motion can cause variable biomechanical effects. In this study, we analysed the biomechanical effect of donning AFO on hemiplegic gait and assessed whether any differences resulted when the AFO was modified. Gait events, plantar pressure, foot contact and centers of pressure(COP) parameters were measured with F-scan pressure sensitive insole system in 21 hemiplegic stroke patients with Brunnstrom's lower extremity stage 3. And those parameters were compaired in each of four different conditions: 1) before donning AFO, 2) donning AFO without any modification, 3) donning AFO with the dis tal part of metatarsal head trimmed off, 4) donning AFO with third condition and weaning a cushioned heel shoes. After donning AFO, total contact area and contact width were increased, and initial contact COP and mean COP were displaced medially. But contact length was not changed and initial contact COP and mean COP were not displaced anteroposteriorly. Anteroposterior displacement of COP, slope and velocity of COP were not also changed after donning AFO. Among various AFO adjustments, there were no significant changes of plantar pressure, foot contact and COP parameters. The results suggest that 1) AFO provides mediolateral stability, but does not provide additional functional rocker actions during stance phase and 2) There were no definite different biomechanical actions among various adjustments of plastic AFO in hemiplegic gait of Brunnstrom's lower extremity stage 3.