Kinetic adaptations of the intact limb in transfemoral amputees using a microprocessor prosthetic knee.

BACKGROUND: In recent decades, high-tech prostheses, including microprocessor-controlled knee (MPK), have been developed to improve the functional abilities of lower limb amputees and to reduce gait asymmetry for the prevention of early joint degradation of the intact limb. The aim of this study was to determine the differences in joint moment and power of the intact limb of transfemoral amputees (TFAs) with an MPK compared to healthy individuals in 2 walking speed conditions. METHODS: Twenty-one TFAs with MPK and matched 21 healthy individuals performed a walking task at spontaneous and rapid self-selected speeds. Spatiotemporal gait parameters and intact limb kinetic data were recorded. RESULTS: The hip and knee moments in the frontal plane during rapid walking were not significantly higher than spontaneous walking in TFA group (respectively p = 0.08 and p = 0.48) and were lower than the control group. In the sagittal plane, the hip extensor moment in TFA was higher than the control group in the landing phase (p < 0.001 in both speed conditions). SIGNIFICANCE: The kinetics of the intact limb of active TFAs with an MPK showed a significant reduction at the knee internal abductor moment compared to the control, potentially limiting risk factors for knee osteoarthritis. However, in the sagittal plane, higher hip extensor moments could favor low-back pain appearance. Gait analysis of lower limb amputees should thus be performed to highlight these kinetic adaptations and then help to propose the most relevant rehabilitation and prevention exercises to limit the appearance of early musculoskeletal degeneration.

Transfemoral amputees adapt their gait during cross-slope walking with specific upper-lower limb coordination.

BACKGROUND: Unilateral lower limb amputees have asymmetrical gaits, particularly on irregular surfaces and slopes. It is unclear how coordination between arms and legs can adapt during cross-slope walking. RESEARCH QUESTION: How do transfemoral amputees (TFAs) adapt their upper-lower limb coordination on cross-slope surfaces? METHODS: Twenty TFA and 20 healthy adults (Ctrl) performed a three-dimensional gait analysis in 2 walking conditions: level ground and cross-slope with prosthesis uphill. Sagittal joint angles and velocities of hips and shoulders were calculated. Continuous relative phases (CRP) were computed between the shoulder and the hip of the opposite side. The closer to 0 the CRP is, the more coordinated the joints are. Curve analysis were conducted using SPM. RESULTS: The mean CRP between the downhill shoulder and the uphill hip was higher in TFA compared to Ctrl (p = 0.02), with a walking conditions effect (p = 0.005). TFA showed significant differences about the end of the stance phase (p = 0.01) between level ground and cross-slope, while Ctrl showed a significant difference (p = 0.008) between these walking conditions at the end of the swing phase. In CRP between the uphill shoulder and the downhill hip, SnPM analysis showed intergroup differences during the stance phase (p < 0.05), but not in the comparison between walking conditions in TFA and Ctrl groups. SIGNIFICANCE: TFA showed an asymmetrical coordination in level ground walking compared to Ctrl. Walking on cross-slope led to upper-lower limb coordination adaptations: this condition impacted the CRP between downhill shoulder and uphill hip in both groups. The management of the prosthetic limb, positioned uphill, induced a reorganization of the coordination with the upper limb of the amputated side. Identifying upper-lower limb coordination adaptations on cross-slope surfaces will help to achieve rehabilitation goals for effective walking in urban environments.

Walking abilities improvements are associated with pelvis and trunk kinematic adaptations in transfemoral amputees after rehabilitation.

BACKGROUND: Rehabilitation can be proposed to transfemoral amputees to improve functional abilities and limit the risk of early degeneration of the musculoskeletal system partly due to altered kinematic behavior. The main aim of this study was to assess the impact of functional rehabilitation on clinical walking tests, gait symmetry and pelvis and trunk kinematics in transfemoral amputees during overground walking. METHODS: Eleven transfemoral amputees followed a functional rehabilitation program with objectives aimed at improving walking abilities and gait symmetry. Clinical functional tests, symmetry between prosthetic and intact sides and trunk and pelvis motions were recorded before and after rehabilitation. FINDINGS: Clinical walking tests were improved after rehabilitation (p < 0.05), and step width was reduced (p = 0.04). Regarding symmetry between the single stances on the prosthesis and intact sides, only a significant decrease in trunk frontal inclination asymmetry was noted after rehabilitation (p = 0.01). Pelvic frontal obliquity was significantly increased during prosthetic (p = 0.02) and intact single stances (p = 0.005). INTERPRETATION: Our study showed a positive effect of rehabilitation on transfemoral amputees functional abilities. These improvements were associated with higher pelvic mobility in frontal plane and a more symmetrical redistribution of the frontal trunk sway around the vertical axis during gait. These results suggest the importance of a postural reeducation program for transfemoral amputees aimed at improving pelvic dynamic control while repositioning the trunk by postural corrections during gait.

Anticipatory postural adjustment during gait initiation in multiple sclerosis patients: A systematic review.

BACKGROUND: Multiple sclerosis (MS) causes balance and walking disorders. Gait initiation is the complex transition between standing and walking and is characterized by two distinct phases: the anticipatory postural adjustment (APA) phase followed by the execution of the first step phase. RESEARCH AIM: To determine alterations in the APA during gait initiation in patients with MS. METHODS: A systematic search was conducted in May 2018. The search was carried out by the use of the following databases: PubMed, Web of Science and the Cochrane Library. The following keywords were used: MS, gait initiation, step initiation, and postural adjustment(s). Outcomes of interest were the variables generally used to assess APA, including electromyography, force-plate data, or video-based data, duration of APA, and length of first step. The Ottawa scale was used to assess the quality of the studies. RESULTS: Eight case-control studies were included; one was a transverse study. A total of 215 MS patients and 116 healthy subjects were included with ages ranging from 22 to 76 years old. In MS patients, Expanded Disability Status Scale (EDSS) scores ranged from 0 to 7. APA CoP displacements were smaller in the anteroposterior axis. Four studies evaluated muscle activation during APA. The latencies of all muscles were delayed, and smaller magnitudes of muscle activity during APA were found, even in the early stage of disease. The first step was shorter in MS patients than in healthy patients. No previous study has reported joint movement or trunk inclination during gait initiation. SIGNIFICANCE: This review illustrates the gap in knowledge of APA alterations in MS patients. APA assessment in the early stage of MS could be an interesting measure to characterize balance, dynamic control and risk of fall for such patients.