Changes in Trunk and Pelvis Motion Among Persons With Unilateral Lower Limb Loss During the First Year of Ambulation

Implementation of relative phase analysis to evaluate continuous interlimb coordination and stability in individuals with lower limb loss: Design and protocol for a retrospective analysis

INTRODUCTION

The number of people with lower limb loss continues to grow, though most research to date has been non-committal and lacks the appropriate clinical guidance required for proper prosthetic prescription. Previous literature using traditional spatiotemporal and biomechanical measures has not accurately identified differences in gait patterns when using different prosthetic devices. Therefore, a knowledge gap remains. To aid in determining the impact of different devices on gait in individuals with lower limb loss, a more sensitive quantitative measure should be used to supplement traditional biomechanical analyses. Continuous measures of coordination and stability, evaluated using relative phase analysis, has been shown to detect changes in gait patterns when traditional variables cannot. However, these measures have yet to be fully assessed in this population. This investigation will fill the knowledge gap by using relative phase analysis to provide a comprehensive description of kinematic behaviour by evaluating continuous interlimb coordination and stability for individuals with lower limb loss.

METHODS AND ANALYSIS

Biomechanical analysis of individuals with lower limb loss during walking activities will be evaluated using relative phase analysis to identify the continuous interlimb coordination and stability relationships between the upper and lower extremities of these individuals. Three-dimensional motion capture will enable kinematic properties of movement to be captured and analysed. Non-traditional measures of analysis will be used.

ETHICS AND DISSEMINATION

This study was approved by the Veterans Affairs New York Harbor Healthcare System Institutional Review Board (IRBNet #1573135, MIRB #1775). Findings will be disseminated through peer-reviewed publications, academic conference presentations, invited workshops, webinars and seminars.

Lumbar Degenerative Disease and Muscle Morphology Before and After Lower Limb Loss in Four Military Patients

INTRODUCTION

Low back pain (LBP) is highly prevalent after lower limb amputation (LLA). Reports describing longitudinal changes in spine health before and after amputation are rare. This study describes lumbar spine pathology, muscle morphology, and the continuum of care for LBP before and after LLA.

MATERIALS AND METHODS

We queried electronic medical records of patients who sought care for LBP before and after unilateral LLA between January 2002 and April 2020 and who had documented lumbar imaging pre- and post-LLA. Patient demographics, muscle morphology, spinal pathology, premorbid and comorbid conditions, self-reported pain, and treatment interventions were assessed.

RESULTS

Four patients with LBP and imaging before and after LLA were identified. Intervertebral disc degeneration progressed after amputation in three patients, whereas facet arthrosis progressed in both female patients. The fat content of lumbar musculature generally increased after amputation. Conservative management of LBP before and after amputation was standard, with progression to steroidal injections.

CONCLUSIONS

Lumbar spine health may degrade after amputation. Here, lumbar muscle size did not change after LLA, yet the fat content increased in combination with increases in facet and intervertebral disc degeneration.

Functional Performance Outcomes of a Powered Knee-Ankle Prosthesis in Service Members With Unilateral Transfemoral Limb Loss

INTRODUCTION

Clinical knowledge surrounding functional outcomes of a powered knee-ankle (PKA) device is limited, particularly among younger and active populations with limb loss. Here, three service members (SM) with unilateral transfemoral limb loss received an optimally tuned PKA prosthesis and device-specific training.

MATERIALS AND METHODS

Once proficiency with the PKA device was demonstrated on benchmark activities, and outcomes with the PKA and standard-of-care (SoC) prostheses were obtained via a modified graded treadmill test, 6-minute walk test, and overground gait assessment.

RESULTS

All SM demonstrated proficiency with the PKA prosthesis within the minimum three training sessions. With the PKA versus SoC prosthesis, cost of transport during the modified graded treadmill test was 4.0% ± 5.2% lower at slower speeds (i.e., 0.6-1.2 m/s), but 7.0% ± 5.1% greater at the faster walking speeds (i.e., ≥1.4 m/s). For the 6-minute walk test, SM walked 83.9 ± 13.2 m shorter with the PKA versus SoC prosthesis. From the overground gait assessment, SM walked with 20.6% ± 10.5% greater trunk lateral flexion and 31.8% ± 12.8% greater trunk axial rotation ranges of motion, with the PKA versus SoC prosthesis.

CONCLUSIONS

Compared to prior work with the PKA in a civilian cohort, although SM demonstrated faster device proficiency (3 versus 12 sessions), SM walked with greater compensatory motions compared to their SoC prostheses (contrary to the civilian cohort). As such, it is important to understand patient-specific factors among various populations with limb loss for optimizing device-specific training and setting functional goals for occupational and/or community reintegration, as well as reducing the risk for secondary complications over the long term.

Comparison of clinical and biomechanical characteristics between individuals with lower limb amputation with and without lower back pain: A systematic review and meta-analysis

BACKGROUND

Lower back pain is a debilitating condition common to individuals with lower limb amputation. It is unclear what risk factors contribute to the development of back pain. This study systematically reviewed and analyzed the available evidence regarding the clinical and biomechanical differences between individuals with amputation, with and without lower back pain.

METHODS

A literature search was conducted in PubMed, Web of Science, Scopus, and CINAHL databases in November 2020 and repeated in June 2021 and June 2022. Studies were included if they reported comparisons of demographic, anthropometric, biomechanical, and other clinical variables between participants with and without LBP. Study quality and potential for reporting bias were assessed. Meta-analyses were conducted to compare the two groups.

FINDINGS

Thirteen studies were included, with aggregated data from 436 participants (239 with LBP; 197 pain free). The median reporting quality score was 37.5%. The included studies enrolled participants who were predominantly male (mean = 91.4%, range = 77.8-100%) and with trauma-related amputation. Meta-analyses showed that individuals with LBP exhibited moderate (3.4 out of 10) but significantly greater pain than those without LBP. We found no between-group differences in age, height, weight, BMI, and time since amputation (p = 0.121-0.682). No significant differences in trunk/pelvic kinematics during gait were detected (p = 0.07-0.446) between the groups.

INTERPRETATION

Demographic, anthropometric, biomechanical, and simple clinical outcome variables may be insufficient for differentiating the risk of developing back pain after amputation. Investigators should be aware of the existing gender bias in sampling and methodological limitations, as well as to consider incorporating psychosocial measures when studying LBP in this clinical population.

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.

Low back pain influences trunk-lower limb joint coordination and balance control during standing in persons with lower limb loss

BACKGROUND

Balance is sustained through multi-joint coordination in response to postural perturbations. Low back pain alters postural responses; however, it is unknown how coordination between the trunk and lower extremities affects center of mass control during standing balance among persons with limb loss, particularly those with back pain.

METHODS

Forty participants with unilateral lower limb loss (23 with back pain) stood with eyes open and closed on a firm surface, while wearing IMUs on the sternum, pelvis, and bilaterally on the thigh, shank, and foot. A state-space model with Kalman filter calculated sagittal trunk, hip, knee, and ankle joint angles. Fuzzy entropy quantified center of mass variability of sagittal angular velocity at the sacrum. Normalized cross-correlation functions identified coordination patterns (trunk-hip, trunk-knee, trunk-ankle). Multiple linear regression predicted fuzzy entropy from cross-correlation values for each pattern, with body mass and amputation level as covariates.

FINDINGS

With eyes open, trunk-lower limb joint coordination on either limb did not predict fuzzy entropy. With eyes closed, positive trunk-hip coordination on the intact limb predicted fuzzy entropy in the pain group (p = 0.02), but not the no pain group. On the prosthetic side, inverse trunk-hip coordination patterns predicted fuzzy entropy in pain group (p = 0.03) only.

INTERPRETATION

Persons with limb loss and back pain demonstrated opposing coordination strategies between the lower limbs and trunk when vision was removed, perhaps identifying a mechanism for pain recurrence. Vision is the dominant source of balance stabilization in this population, which may increase fall risk when visual feedback is compromised.