Determination of the correlation between muscle forces obtained from OpenSim and muscle activities obtained from electromyography in the elderly.

Measurement of muscle forces related to aging can help to better identify the gait impairment mechanisms in the elderly. To this end, musculoskeletal modeling has been developed to estimate muscle forces. This study aimed to check the validity of OpenSim modeling (i.e., computed muscle control) approach in elderly subjects. Kinematic and kinetic data and Electromyography (EMG) signals for four different muscles were collected in nine healthy elderly males during walking. Dynamic simulation was done within OpenSim. Correlation analysis was performed to quantitatively compare the maximum estimated muscle forces with maximum measured muscle activities during the first double limb support, single limb support, and the second double limb support phases. The area-time plots of OpenSim and EMG data during gait cycle were obtained for qualitative assessment. In quantitative assessment, a low to moderate correlation was observed for the peak of muscle force and muscle activation of four muscles during sub phases of gait. The muscle forces pattern from OpenSim was found to be relatively similar to the muscle activity pattern from EMG especially for Gastrocnemius Medialis. A low to moderate consistency between OpenSim and EMG in the elderly can be explained by using a single mathematical estimation approach.

The physiological cost index of walking with a powered knee-ankle-foot orthosis in subjects with poliomyelitis: A pilot study.

BACKGROUND: A powered knee-ankle-foot orthosis was developed to provide restriction of knee flexion during stance phase and active flexion and extension of the knee during swing phase of gait. OBJECTIVE: The purpose of this study was to determine its effect on the physiological cost index, walking speed and the distance walked in people with poliomyelitis compared to when walking with a knee-ankle-foot orthosis with drop lock knee joints. STUDY DESIGN: Quasi experimental study. METHODS: Seven subjects with poliomyelitis volunteered for the study and undertook gait analysis with both types of knee-ankle-foot orthosis. RESULTS: Walking with the powered knee-ankle-foot orthosis significantly reduced walking speed (p = 0.015) and the distance walked (p = 0.004), and also, it did not improve physiological cost index values (p = 0.009) compared to walking with the locked knee-ankle-foot orthosis. CONCLUSION: Using a powered knee-ankle-foot orthosis did not significantly improve any of the primary outcome measures during walking for poliomyelitis subjects. CLINICAL RELEVANCE: This powered knee-ankle-foot orthosis design did not improve the physiological cost index of walking for people with poliomyelitis when compared to walking with a knee-ankle-foot orthosis with drop lock knee joints. This may have been due to the short training period used or the bulky design and additional weight of the powered orthosis. Further research is therefore warranted.

Comparison of gait between healthy participants and persons with spinal cord injury when using the advanced reciprocating gait orthosis.

BACKGROUND: The advanced reciprocating gait orthosis (ARGO) has a rigid structure which provides restricted movement at the hip, knee, and ankle joints and incorporates a pelvic section with an extended section in the lumbar region. Healthy subjects, when walking with an RGO in situ, could feasibly demonstrate the level of limitation in movement imposed by ARGO-assisted ambulation. OBJECTIVE: The aim of this study was to compare the function of the advanced reciprocating gait orthosis when fitted with the dorsiflexion-assist ankle-foot orthoses on temporal-spatial parameters and kinematics of walking in both able-bodied people and those with spinal cord injury. STUDY DESIGN: Quasi experimental design. METHODS: Data were acquired from six able-bodied and four spinal cord injury subjects who used an advanced reciprocating gait orthosis which incorporated dorsiflexion-assist ankle-foot orthoses. Kinematics and temporal-spatial parameters were calculated and compared. RESULTS: All able-bodied individuals walked with speeds which were only approximately one-third that of when walking without an orthosis. The mean step length and cadence were both reduced by 48% and 6%, respectively. There were significant differences in hip, knee, and ankle joint range of motions between normal walking and walking with the advanced reciprocating gait orthosis both in able-bodied subjects and patients with spinal cord injury. There were also significant differences in the speed of walking, cadence, step length, hip range of motion, and ankle range of motion when using the advanced reciprocating gait orthosis between the two groups. CONCLUSION: Temporal-spatial parameters and lower limb sagittal plane kinematics of walking were altered compared to normal walking, especially when spinal cord injury subjects walked with the advanced reciprocating gait orthosis compared to the able-bodied subjects. CLINICAL RELEVANCE: To produce an improvement in RGO function, an increase in walking performance should involve attention to improvement of hip, knee, and ankle joint kinematics, which differs significantly from normal walking.

The influence of thermoplastic thoraco lumbo sacral orthoses on standing balance in subjects with idiopathic scoliosis.

BACKGROUND: Idiopathic scoliosis patients have postural equilibrium problems. OBJECTIVE: The objective of this study was to assess postural control in subjects with idiopathic scoliosis following a 4-month intervention in an unbraced position. STUDY DESIGN: Quasi-experimental. METHODS: Eight healthy girls and eight girls with idiopathic scoliosis took part. A Kistler force platform was used with a frequency of 100 Hz for recording data. The center of pressure was recorded in different positions out of brace for scoliosis and healthy subjects. Test conditions were single limb and double limb stance, with eyes open and closed, and foam and rigid surfaces. RESULTS: The data reflected a weak balance of idiopathic scoliosis subjects compared to healthy subjects. After 1 and 4 months of wearing the brace, center of pressure and center of gravity sway increased in the majority of the tests, although there were no significant differences in any of the test conditions (p > 0.05). While the center of pressure sway in medio-lateral direction decreased after 4 months of wearing a brace, in other variables center of pressure and center of gravity sway increased. CONCLUSION: Idiopathic scoliosis patients have weak balance in comparison to healthy subjects. In addition, following a period of 4 months of wearing a brace, balance parameters in the scoliosis subjects did not improve. The results show that we need more follow-up of orthoses wearing in idiopathic scoliosis subjects and suggest more studies at least 1-year follow-up to identify the efficiency of brace wear on balance. CLINICAL RELEVANCE: Scoliosis can alter postural stability and balance performance during quiet standing. Spinal deformity can alter a subject's ability to compensate for postural changes and cause gait deviations. This study investigated balance differences between the healthy and idiopathic scoliosis patients and the results of thoraco lumbo sacral orthosis brace wear. It might provide some new insight into the conservative treatment of idiopathic scoliosis patients for clinicians and researchers.

The effect of trunk extension on physiological cost index in spinal cord injury patients when using the advanced reciprocating gait orthosis: A pilot study.

BACKGROUND: People with spinal cord injury walk with a flexed trunk when using reciprocating gait orthoses for walking. Reduction in trunk flexion during ambulation has been shown to improve gait parameters for reciprocating gait orthosis users. OBJECTIVE: The aim of this study was to investigate the effect on energy expenditure when spinal cord injury patients ambulate with an advanced reciprocating gait orthosis while wearing a thoracolumbosacral orthosis to provide trunk extension. STUDY DESIGN: Quasi experimental study. METHODS: Four patients with spinal cord injury were fitted with an advanced reciprocating gait orthosis after completing a specific gait training program. Patients walked along a flat walkway using the advanced reciprocating gait orthosis as a control condition and also while additionally wearing a thoracolumbosacral orthosis at their self-selected walking speed. A stopwatch and a polar heart rate monitor were used to measure walking speed and heart rate. RESULTS: Walking speed, the distance walked, and the physiological cost index all improved when walking with the advanced reciprocating gait orthosis/thoracolumbosacral orthosis test condition compared to walking with no thoracolumbosacral orthosis in situ. CONCLUSION: Spinal cord injury patients can improve their walking speed, walking distance, and physiological cost index when wearing a thoracolumbosacral orthosis in conjunction with an advanced reciprocating gait orthosis, which may be attributed to the trunk extension provided by the thoracolumbosacral orthosis. CLINICAL RELEVANCE: It is concluded that wearing thoracolumbosacral orthosis in association with an advanced reciprocating gait orthosis could be an effective alternative in rehabilitation for thoracic level of paraplegic patients to promote their health and well-being.

The influence of a powered knee-ankle-foot orthosis on walking in poliomyelitis subjects: A pilot study.

BACKGROUND: Traditionally, the anatomical knee joint is locked in extension when walking with a conventional knee-ankle-foot orthosis. A powered knee-ankle-foot orthosis was developed to provide restriction of knee flexion during stance phase and active flexion and extension of the knee during swing phase of gait. OBJECTIVE: The purpose of this study was to determine differences of the powered knee-ankle-foot orthosis compared to a locked knee-ankle-foot orthosis in kinematic data and temporospatial parameters during ambulation. STUDY DESIGN: Quasi-experimental design. METHODS: Subjects with poliomyelitis (n = 7) volunteered for this study and undertook gait analysis with both the powered and the conventional knee-ankle-foot orthoses. Three trials per orthosis were collected while each subject walked along a 6-m walkway using a calibrated six-camera three-dimensional video-based motion analysis system. RESULTS: Walking with the powered knee-ankle-foot orthosis resulted in a significant reduction in both walking speed and step length (both 18%), but a significant increase in stance phase percentage compared to walking with the conventional knee-ankle-foot orthosis. Cadence was not significantly different between the two test conditions (p = 0.751). There was significantly higher knee flexion during swing phase and increased hip hiking when using the powered orthosis. CONCLUSION: The new powered orthosis permitted improved knee joint kinematic for knee-ankle-foot orthosis users while providing knee support in stance and active knee motion in swing in the gait cycle. Therefore, the new powered orthosis provided more natural knee flexion during swing for orthosis users compared to the locked knee-ankle-foot orthosis. CLINICAL RELEVANCE: This orthosis has the potential to improve knee joint kinematics and gait pattern in poliomyelitis subjects during walking activities.

The gait and energy efficiency of stance control knee-ankle-foot orthoses: A literature review.

BACKGROUND: The use of knee-ankle-foot orthoses with drop locked knee joints produces some limitations for walking in subjects with quadriceps muscle weakness. The development of stance control orthoses can potentially improve their functionality. OBJECTIVES: The aim of this review was to compare the evidence of the effect of stance control orthoses to knee-ankle-foot orthoses with drop locked knee joints in improving kinematic variables and energy efficiency of walking by subjects with quadriceps muscle weakness caused by different pathologies. STUDY DESIGN: Literature review. METHODS: Based on selected keywords and their composition, a search was performed in Google Scholar, PubMed, ScienceDirect, and ISI Web of Knowledge databases. In total, 18 articles were finally chosen for review. RESULTS: The results of this study demonstrated that this type of orthosis can improve the walking parameters of subjects with quadriceps muscle weakness and spinal cord injury patients when compared to a locked knee-ankle-foot orthosis. CONCLUSION: There is evidence to show that stance control orthosis designs improve the gait kinematics but not energetic of knee-ankle-foot orthosis users. Development of new designs of stance control orthoses to provide a more normal pattern of walking is still required. CLINICAL RELEVANCE: Stance control orthoses are a new generation of orthotic intervention that could potentially be significant in assisting to improve the gait kinematics by knee-ankle-foot orthosis users.

The effect of new method of suspension on quality of life, satisfaction, and suspension in patients with finger prostheses.

BACKGROUND: The use of a finger prosthesis following finger amputation is a common approach that is linked to many factors. OBJECTIVES: The aim of this study was to evaluate the effect of a new method of suspension on quality of life, satisfaction, and suspension in these patients. STUDY DESIGN: Quasi-experimental. METHOD: A total of 24 patients with finger amputation and 12 healthy subjects as control group participated in this study. Two types of finger prostheses with conventional suction suspension and new method suspension were provided. A force gauge was used to evaluate suspension force along with a World Health Organization Quality of Life-BREF questionnaire instrument. Satisfaction of the prosthesis was also evaluated using a visual analog scale. RESULTS: There was significant difference in quality of life assessment between the patient group and healthy control group, but there was no statistical difference (p > 0.05) between the two patients groups at baseline and after prosthesis use. Using finger prosthesis improved all domains after prosthesis wearing in patients with finger amputations. There were significant differences (p < 0.05) between the two types of prosthesis in terms of suspension and satisfaction. CONCLUSION: Wearing the prosthesis with the new method of suspension had an effective role in terms of providing suspension and an increase in satisfaction in patients with finger amputation. CLINICAL RELEVANCE: Patients with finger amputation usually use a prosthesis with a simple suspension technique, yet many of these patients experience atrophy and subsequently loss of appropriate suspension. This paper presents a new method of suspension and showed that using this approach improved satisfaction and suspension in patients with finger amputation.