The relationship between pelvis-trunk coordination and low back pain in individuals with transfemoral amputations

Lower-extremity inter-joint coordination variability in active individuals with transtibial amputation and healthy males during gait

This study was aimed to compare the variability of inter-joint coordination in the lower-extremities during gait between active individuals with transtibial amputation (TTAs) and healthy individuals (HIs). Fifteen active male TTAs (age: 40.6 ± 16.24 years, height: 1.74 ± 0.09 m, and mass: 71.2 ± 8.87 kg) and HIs (age: 37.25 ± 13.11 years, height: 1.75 ± 0.06 m, and mass: 74 ± 8.75 kg) without gait disabilities voluntarily participated in the study. Participants walked along a level walkway covered with Vicon motion capture system, and their lower-extremity kinematics data were recorded during gait. The spatiotemporal gait parameters, lower-extremity joint range of motion (ROM), and their coordination and variability were calculated and averaged to report a single value for each parameter based on biomechanical symmetry assumption in the lower limbs of HIs. Additionally, these parameters were separately calculated and reported for the intact limb (IL) and the prosthesis limb (PL) in TTAs individuals. Finally, a comparison was made between the averaged values in HIs and those in the IL and PL of TTAs subjects. The results showed that the IL had a significantly lower stride length than that of the PL and averaged value in HIs, and the IL had a significantly lower knee ROM and greater stance-phase duration than that of HIs. Moreover, TTAs showed different coordination patterns in pelvis-to-hip, hip-to-knee, and hip-to-ankle couplings in some parts of the gait cycle. It concludes that the active TTAs with PLs walked with more flexion of the knee and hip, which may indicate a progressive walking strategy and the differences in coordination patterns suggest active TTA individuals used different neuromuscular control strategies to adapt to their amputation. Researchers can extend this work by investigating variations in these parameters across diverse patient populations, including different amputation etiologies and prosthetic designs. Moreover, Clinicians can use the findings to tailor rehabilitation programs for TTAs, emphasizing joint flexibility and coordination.

Lumbopelvic movement coordination during walking improves with transfemoral bone anchored limbs: Implications for low back pain

BACKGROUND

Low back pain (LBP) is more prevalent in patients with transfemoral amputation using socket prostheses than able-bodied individuals, in part due to altered spinal loading caused by aberrant lumbopelvic movement patterns. Early evidence surrounding bone-anchored limb functional outcomes is promising, yet it remains unknown if this novel prosthesis influences LBP or movement patterns known to increase its risk.

RESEARCH QUESTION

How are self-reported measures of LBP and lumbopelvic movement coordination patterns altered when using a unilateral transfemoral bone-anchored limb compared to a socket prosthesis?

METHODS

Fourteen patients with unilateral transfemoral amputation scheduled to undergo intramedullary hardware implantation for bone-anchored limbs due to failed socket use were enrolled in this longitudinal observational cohort study (7 F/7 M, Age: 50.2±12.0 years). The modified Oswestry Disability Index (mODI) (self-reported questionnaire) and whole-body motion capture during overground walking were collected before (with socket prosthesis) and 12-months following bone-anchored limb implantation. Lumbopelvic total range of motion (ROM) and continuous relative phase (CRP) segment angles were calculated during 10 bilateral gait cycles. mODI, total ROM, CRP and CRP variabilities were compared between time points.

RESULTS

mODI scores were significantly reduced 12-months after intramedullary hardware implantation for the bone-anchored limb (P = 0.013). Sagittal plane trunk and pelvis total ROM during gait were reduced after implantation (P = 0.001 and P < 0.001, respectively). CRP values were increased (more anti-phase) in the sagittal plane during single limb stance and reduced (more in-phase) in the transverse plane during pre-swing of the amputated limb gait cycle (P << 0.001 and P = 0.029, respectively). No differences in CRP values were found in the frontal plane.

SIGNIFICANCE

Decreases in mODI scores and lumbopelvic ROM, paired with the changes in lumbopelvic coordination, indicate that bone-anchored limbs may reduce LBP symptoms and reduce compensatory movement patterns for people with unilateral transfemoral amputation.

Comparing spinal loads in individuals with unilateral transtibial amputation with and without chronic low back pain: An EMG-informed approach

Chronic low back pain (cLBP) is highly prevalent after lower limb amputation (LLA), likely due in part to biomechanical factors. Here, three-dimensional full-body kinematics and kinetics during level-ground walking, at a self-selected and three controlled speeds (1.0, 1.3, and 1.6 m/s), were collected from twenty-one persons with unilateral transtibial LLA, with (n = 9) and without cLBP (n = 12). Peak compressive, mediolateral, and anteroposterior L5-S1 spinal loads were estimated from a full-body, transtibial amputation-specific OpenSim model and compared between groups. Predicted lumbar joint torques from muscle activations were compared to inverse dynamics and predicted and measured electromyographic muscle activations were compared for model evaluation and verification. There were no group differences in compressive or anterior shear forces (p > 0.466). During intact stance, peak ipsilateral loads increased with speed to a greater extent in the cLBP group vs. no cLBP group (p=0.023), while during prosthetic stance, peak contralateral loads were larger in the no cLBP group (p=0.047) and increased to a greater extent with walking speed compared to the cLBP group (p=0.008). During intact stance, intact side external obliques had higher activations in the no cLBP group (p=0.039), and internal obliques had higher activations in the cLBP group at faster walking speeds compared to the no cLBP group. Predicted muscle activations demonstrated similar activation patterns to electromyographic-measured activations (r = 0.56-0.96), and error between inverse dynamics and simulated spinal moments was low (0.08 Nm RMS error). Persons with transtibial LLA and cLBP may adopt movement strategies during walking to reduce mediolateral shear forces at the L5-S1 joint, particularly as walking speed increases. However, future work is needed to understand the time course from pain onset to chronification and the cumulative influence of increased spinal loads over time.

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.

Absent loading response knee flexion: The impact on gait kinetics and centre of mass motion in individuals with unilateral transfemoral amputation, and the effect of microprocessor controlled knee provision

BACKGROUND

Individuals with unilateral transfemoral amputation walk with increased levels of asymmetry, and this is associated with reduced gait efficiency, back pain and overuse of the intact limb. This study investigated the effect of walking with a unilateral absence of loading response knee flexion on the symmetry of anterior-posterior kinetics and centre of mass accelerations.

METHODS

A retrospective cohort study design was used, assessing three-dimensional gait data from individuals with unilateral transfemoral amputation (n = 56). The anterior-posterior gait variables analysed included; peak ground reaction forces, impulse, centre of mass acceleration, as well as rate of vertical ground reaction force increase in early stance. With respect to these variables, this study assessed the symmetry between intact and prosthetic limbs, compared intact limbs against a healthy unimpaired control group, and evaluated effect on symmetry of microprocessor controlled knee provision.

FINDINGS

Significant between-limb asymmetries were found between intact and prosthetic limbs across all variables (p < 0.0001). Intact limbs showed excessive loading when compared with control group limbs after speed normalisation across all variables (p < 0.0001). No improvement in kinetic symmetry following microprocessor controlled knee provision was found.

INTERPRETATION

The gait asymmetries for individuals with transfemoral amputation identified in this study suggest that more should be done by developers to address the resultant overloading of the intact limb, as this is thought to have negative long-term effects. The provision of microprocessor controlled knees did not appear to improve the asymmetries faced by individuals with transfemoral amputation, and clinicians should be aware of this when managing patient expectations.

Exercise Therapy in Nonspecific Low Back Pain among Individuals with Lower-Limb Amputation: A Systematic Review

Low back pain is very common condition that often becomes a long-lasting problem in prostheses users after lower limb amputation. The presented study aims to decide the potential benefits of exercise therapy on low back pain among lower limb amputees by using a systematic review. The PICO technique was used to answer the primary issue of this review: Does exercise treatment lessen the prevalence of low back pain in the population of lower limb amputees? Systematic review was conducted in the following databases: Medline-PubMed, EMBASE, Scopus, and Web of Science. Studies up to September 2010 published in English are included. Aim, target population, development and execution strategies, and treatment suggestions were among the data gathered. The primary outcomes of interest were exercise interventions as a therapy for low back pain but only two articles met including criteria. The search was broadened and 21 studies describing biomechanical changes in gait and pelvic-spine posture were analysed. This review indicates that movement therapy is a potential treatment strategy in low back pain among amputees. The major limitation of the study is the very heterogenous group of subjects in terms of amputation level, baseline activity level and comorbidities. We used a procedure that was registered in PROSPERO (CRD42022345556) to perform this systematic review of systematic reviews. There is a necessity of good quality research for concluding a consensus of exercise intervention.

The effect of muscle atrophy in people with unilateral transtibial amputation for three activities: Gait alone does not tell the whole story

Amputation imposes significant challenges in locomotion to millions of people with limb loss worldwide. The decline in the use of the residual limb results in muscle atrophy that affects musculoskeletal dynamics in daily activities. The aim of this study was to quantify the lower limb muscle volume discrepancy based on magnetic resonance (MR) imaging and to combine this with motion analysis and musculoskeletal modelling to quantify the effects in the dynamics of key activities of daily living. Eight male participants with traumatic unilateral transtibial amputation were recruited who were at least six months after receiving their definitive prostheses. The muscle volume discrepancies were found to be largest at the knee extensors (35 %, p = 0.008), followed by the hip abductors (17 %, p = 0.008). Daily activities (level walking, standing up from a chair and ascending one step) were measured in a motion analysis laboratory and muscle and joint forces quantified using a detailed musculoskeletal model for people with unilateral transtibial amputation which was calibrated in terms of the muscle volume discrepancies post-amputation at a subject-specific level. Knee extensor muscle forces were lower at the residual limb than the intact limb for all activities (p ≤ 0.008); residual limb muscle forces of the hip abductors (p ≤ 0.031) and adductors (p ≤ 0.031) were lower for standing-up and ascending one step. While the reduced knee extensor force has been reported by other studies, our results suggest a new biomechanically-based mitigation strategy to improve functional mobility, which could be achieved through strengthening of the hip abd/adductor muscles.

Continuous relative phases of walking with an articulated passive ankle-foot prosthesis in individuals with a unilateral transfemoral and transtibial amputation: an explorative case-control study

BACKGROUND

A mechanical ankle-foot prosthesis (Talaris Demonstrator) was developed to improve prosthetic gait in people with a lower-limb amputation. This study aims to evaluate the Talaris Demonstrator (TD) during level walking by mapping coordination patterns based on the sagittal continuous relative phase (CRP).

METHODS

Individuals with a unilateral transtibial amputation, transfemoral amputation and able-bodied individuals completed 6 minutes of treadmill walking in consecutive blocks of 2 minutes at self-selected (SS) speed, 75% SS speed and 125% SS speed. Lower extremity kinematics were captured and hip-knee and knee-ankle CRPs were calculated. Statistical non-parametric mapping was applied and statistical significance was set at 0.05.

RESULTS

The hip-knee CRP at 75% SS walking speed with the TD was larger in the amputated limb of participants with a transfemoral amputation compared to able-bodied individuals at the beginning and end of the gait cycle (p = 0.009). In people with a transtibial amputation, the knee-ankle CRP at SS and 125% SS walking speeds with the TD were smaller in the amputated limb at the beginning of the gait cycle compared to able-bodied individuals (p = 0.014 and p = 0.014, respectively). Additionally, no significant differences were found between both prostheses. However, visual interpretation indicates a potential advantage of the TD over the individual's current prosthesis.

CONCLUSION

This study provides lower-limb coordination patterns in people with a lower-limb amputation and reveals a possible beneficial effect of the TD over the individuals' current prosthesis. Future research should include a well-sampled investigation of the adaptation process combined with the prolonged effects of the TD.

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.

Low Back Pain in People With Lower Limb Amputation: A Cross-Sectional Study

STUDY DESIGN

A cross-sectional study based on an online questionnaire.

OBJECTIVE

The aim was to investigate the prevalence and intensity of low back pain (LBP) in people with lower limb amputation (LLA) and to analyze the association factors that can influence the genesis of LBP.

SUMMARY OF BACKGROUND DATA

It is still unclear whether LBP is more prevalent in the amputated population than in its nonamputated counterpart. Given the multifactorial nature of LBP, it is necessary to explore possible factors that can influence its presence and intensity, to build a solid background to define a better rehabilitation pathway for the management of these people.

METHODS

The online questionnaire included six sections: informed consent of the study, demographic information, comorbid conditions, history of LLA, history of LBP, and acceptance of the amputation.

RESULTS

Between March and June 2021, 239 participants [mean age (SD): 49.2 (11.5); female 11%] completed the survey (response rate: 32%). From the results of this study, LBP in LLA showed a prevalence of 82% postamputation and 70% in the last year. A logistic regression with a backward method showed that participants who had problems in the not affected leg presented 1.58 (95% confidence interval: 0.70; 2.45) times higher odds to have LBP after the amputation.

CONCLUSION

This study shows that the prevalence of LBP in lower limb amputees appears to be higher than in the general population, with similar levels of pain intensity and frequency. The highest percentage of people with a sedentary lifestyle not practicing any kind of sports emphasizes the importance of educating this population on the importance of physical activity. New strategies to invest in the education of this population in terms of physical activity are needed.

LEVEL OF EVIDENCE

Level 4.

Gait asymmetry is associated with performance-based physical function among adults with lower-limb amputation

BACKGROUND

Adults with lower-limb amputation walk with an asymmetrical gait and exhibit poor functional outcomes, which may negatively impact quality-of-life.

OBJECTIVE

To evaluate associations between gait asymmetry and performance-based physical function among adults with lower-limb amputation.

METHODS

A cross-sectional study involving 38 adults with a unilateral transtibial (N = 24; 62.5 ± 10.5 years) or transfemoral amputation (N = 14; 59.9 ± 9.5 years) was conducted. Following gait analysis (capturing step length and stance time asymmetry at self-selected (SSWS) and fast walking speeds (FWS)), participants completed performance-based measures (i.e. Timed Up and Go (TUG), the 10-Meter Walk Test (10mwt), and the 6-Minute Walk Test (6MWT)).

RESULTS

Step length and stance time asymmetry (at SSWS and FWS) were significantly correlated with each performance-based measure (p < .001 to p = .035). Overall, models with gait measures obtained at SSWS explained 40.1%, 46.8% and 40.1% of the variance in TUG-time (p = .022), 10mwt-speed (p = .003) and 6MWT-distance (p = .010), respectively. Models with gait measures obtained at FWS explained 70.0%, 59.8% and 51.8% of the variance in TUG-time (p < .001), 10mwt-speed (p < .001), and 6MWT-distance (p < .001), respectively.

CONCLUSIONS

Increases in step length or stance time asymmetry are associated with increased TUG-time, slower 10mwt-speed, and reduced 6MWT-distance. Findings suggest gait asymmetry may be a factor in poor functional outcomes following lower-limb amputation.

Parasport: Effects on Musculoskeletal Function and Injury Patterns

➤

Sports participation can improve gait, muscle strength, and functional abilities in patients with a wide variety of disabilities. Para athletes are also at substantial risk for injury during sports participation.

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Ambulant athletes with cerebral palsy are at risk for soft-tissue injuries about the knee as well as foot and ankle injuries. Wheelchair athletes are at risk for osteoporotic fractures and shoulder girdle injuries. Limb-deficient athletes are prone to low back pain and overuse injuries of the contralateral extremity.

➤

Para athletes are vulnerable to abuse during sports participation, and physicians should promptly report any possible abuse or mistreatment.

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Orthopaedic surgeons should understand disability and sport-specific risk factors for injury in para athletes in order to initiate early management and injury prevention protocols.

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.

Overall Greater Demands on the Musculoskeletal System at Multiple Walking Speeds in Service Members With Lower Limb Loss

Individuals with lower limb loss often walk with altered/asymmetric movement mechanics, postulated as a catalyst for development of low back and knee pain. Here, the authors simultaneously investigated trunk-pelvic movement patterns and lower limb joint kinematics and kinetics among 38 males with traumatic, unilateral lower limb loss (23 transtibial and 15 transfemoral), and 15 males without limb loss, at a self-selected and 2 standardized (1.0 and 1.6 m/s) speeds. Individuals with versus without lower limb loss walked with greater trunk range of motion in the frontal and transverse planes at all speeds (despite ∼10% slower self-selected speeds). At all speeds, individuals with versus without limb loss exhibited +29% larger medial ground reaction forces, and at 1.6 m/s also exhibited +50% to 110% larger vertical hip power generation, +27% to 80% larger vertical hip power absorption, and +21% to 90% larger medial-lateral hip power absorption. Moreover, pervasive biomechanical differences between transtibial versus transfemoral limb loss identify amputation-level movement strategies. Overall, greater demands on the musculoskeletal system across walking speeds, particularly at the hip, knee, and low back, highlight potential risk factors for the development/recurrence of prevalent secondary musculoskeletal conditions (eg, joint degeneration and pain) following limb loss.

The impact of transfemoral socket adduction on pelvic and trunk stabilization during level walking - A biomechanical study

BACKGROUND

It is common practice to align transfemoral prosthetic sockets in adduction, due to the physiologic, adducted femoral alignment in unimpaired legs. An adducted femoral and socket alignment helps tightening hip abductors to stabilize the pelvis and reduce pelvic and trunk related compensatory movements.

RESEARCH QUESTION

How do different socket adduction conditions (SAC) of transfemoral sockets affect pelvic and trunk stabilization during level ground walking in the frontal plane?

METHODS

Seven persons with transfemoral amputation with medium residual limb length participated in this study. The prosthetic alignment in the sagittal plane was performed according to established recommendations. SAC varied (0°, 3°, 6°, 9°). Kinematic and kinetic parameters were recorded in a gait laboratory with a 12-camera optoelectronic system and two piezoelectric force plates embedded in a 12-m walkway. The measurements were performed during level ground walking with self-selected comfortable gait speed.

RESULTS

In the frontal plane, nearly all investigated kinematic and kinetic parameters showed a strong correlation with the SAC. The pelvis was raised on the contralateral side throughout the gait cycle with increasing SAC. During the prosthetic side stance phase, the mean shoulder obliquity and mean lateral trunk lean to the prosthetic side tended to be reduced with increased SAC. Prosthetic side hip abduction moment decreased with increasing SAC.

SIGNIFICANCE

The results confirm that transfemoral SAC contributes to pelvic stabilization and reduced compensatory movements of the pelvis and trunk. Transfemoral SAC of 6 ± 1° for bench alignment seems adequate for amputees with medium residual limb length. However, the optimum value for the individual patient may differ slightly.

Coordination of Axial Trunk Rotations During Gait in Low Back Pain. A Narrative Review

Chronic low back pain patients have been observed to show a reduced shift of thorax-pelvis relative phase towards out-of-phase movement with increasing speed compared to healthy controls. Here, we review the literature on this phase shift in patients with low back pain and we analyze the results presented in literature in view of the theoretical motivations to assess this phenomenon. Initially, based on the dynamical systems approach to movement coordination, the shift in thorax-pelvis relative phase with speed was studied as a self-organizing transition. However, the phase shift is gradual, which does not match a self-organizing transition. Subsequent emphasis in the literature therefore shifted to a motivation based on biomechanics. The change in relative phase with low back pain was specifically linked to expected changes in trunk stiffness due to 'guarded behavior'. We found that thorax-pelvis relative phase is affected by several interacting factors, including active drive of thorax rotation through trunk muscle activity, stride frequency and the magnitude of pelvis rotations. Large pelvis rotations and high stride frequency observed in low back pain patients may contribute to the difference between patients and controls. This makes thorax-pelvis relative phase a poor proxy of trunk stiffness. In conclusion, thorax-pelvis relative phase cannot be considered as a collective variable reflecting the orderly behaviour of a complex underlying system, nor is it a marker of specific changes in trunk biomechanics. The fact that it is affected by multiple factors may explain the considerable between-subject variance of this measure in low back pain patients and healthy controls alike.

Lumbosacral injuries in elite Paralympic athletes with limb deficiency: a retrospective analysis of patient records

Background

Compared to injury data in able-bodied athletes, relatively little literature exists for Paralympic athletes. Injury data underpins the design and evaluation of injury prevention strategies in elite sport. The aim of this study was to investigate frequency, characteristics and management of lumbosacral injuries in elite athletes with limb deficiency.

Methods

A retrospective analysis of injuries in elite athletes with limb deficiency (2008 to 2017) was conducted using available data extracted from The English Institute of Sport (EIS) clinical records. Eligibility criteria: funded athletes, eligible for EIS physiotherapy support with full or partial limb deficiency. Data were analysed descriptively using frequencies.

Results

A total of 107 injuries from 32 athletes were included. Participants comprised 18 men (59%), from 9 sports, with mean age for index injuries of 27 years (range 18 to 38 years) and 15 with congenital limb deficiency (47%). Average number of index injuries for congenital and traumatic limb deficient groups were 13 and 19, respectively. Where injury onset was recorded (n=79), half of injuries occurred during training (40%, n=43). Arthrogenic structures accounted for 32.7% of injuries, myogenic 26.2%, with neurogenic, discogenic and osteogenic each <5%. The number of treatments delivered in each injury episode ranged from 1 to 43, with symptom resolution taking 2 to 439 days.

Conclusion

Elite athletes with limb deficiency experience lumbosacral injuries predominantly involving muscles and joints. While consistency and accuracy of data recording limits definitive conclusions, findings highlight the importance of precision in recording injury data as part of surveillance to enable implementation of effective injury prevention strategies.

Trunk Postural Control Strategies Among Persons With Lower-Limb Amputation While Walking and Performing a Concurrent Task

Altered trunk movements during gait in persons with lower-limb amputation are often associated with an increased risk for secondary health conditions; however, the postural control strategies underlying such alterations remain unclear. In this secondary analysis, the authors employed nonlinear measures of triplanar trunk accelerations via short-term Lyapunov exponents to investigate trunk local stability as well as spatiotemporal gait parameters to describe gait mechanics. The authors also evaluated the influence of a concurrent task on trunk local stability and gait mechanics to explore if competition for neuromuscular processing resources can assist in identifying unique strategies to control kinematic variability. Sixteen males with amputation-8 transtibial and 8 transfemoral-and 8 uninjured males (controls) walked on a treadmill at their self-selected speed (mean = 1.2 m/s ±10%) in 5 experimental conditions (8 min each): 4 while performing a concurrent task (2 walking and 2 seated) and 1 with no concurrent task. Individuals with amputation demonstrated significantly smaller Lyapunov exponents than controls in all 3 planes of motion, regardless of concurrent task or level of amputation (P < .0001). Individuals with transfemoral amputation walked with wider strides compared with individuals with transtibial amputation and controls (P < .0001). Individuals with amputation demonstrated more trunk kinematic variability in the presence of wider strides compared with individuals without amputation, and it appears that performing a concurrent cognitive task while walking did not change trunk or gait mechanics.

Can high-functioning amputees with state-of-the-art prosthetics walk normally? A kinematic and dynamic study of 40 individuals

BACKGROUND

Previous work has highlighted the highly functional post-rehabilitation level of military individuals who sustained traumatic amputation. Understanding how these individuals walk with their prosthesis could be key to setting a precedent for what is realistically possible in the rehabilitation of individuals with amputations.

OBJECTIVE

The aim of this paper is to answer how "normal" should the gait of an individual with an amputation(s) be and can we aspire to mimic able-bodied gait with the most advanced prosthetics in highly functioning individuals?

METHODS

This was a cross-sectional study comparing the gait of severely injured and highly functional UK trans-tibial (n=10), trans-femoral (n=10) and bilateral trans-femoral (n=10) military amputees after completion of their rehabilitation programme to that of able-bodied controls (n=10). Joint kinematics and kinetics of the pelvis, hip, knee and ankle were measured with 3-D gait analysis during 5min of walking on level ground at a self-selected speed. Peak angle, moment or range of motion of intact and prosthetic limbs were compared to control values.

RESULTS

Joint kinematics of unilateral trans-tibial amputees was similar to that of controls. Individuals with a trans-femoral amputation walked with a more anterior tilted pelvis (P=0.006), with reduced range of pelvic obliquity (P=0.0023) and ankle plantarflexion (P<0.001) than controls. Across all amputee groups, hip joint moments and power were greater and knee and ankle joint moments were less than for controls.

CONCLUSIONS

This is the first study to provide a comprehensive description of gait patterns of unilateral trans-tibial, trans-femoral and bilateral trans-femoral amputees as compared with healthy able-bodied individuals. The groups differed in joint kinematics and kinetics, but these can be expected in part because of limitations in prosthesis and socket designs. The results from this study could be considered benchmark data for healthcare professionals to compare gait patterns of other individuals with amputation who experienced similar injuries and rehabilitation services.

Relationships between mediolateral trunk-pelvic motion, hip strength, and knee joint moments during gait among persons with lower limb amputation

BACKGROUND

Repeated exposures to larger lateral trunk-pelvic motion and features of knee joint loading likely influence the onset of low back pain and knee osteoarthritis among persons with lower-limb amputation. Decreased hip abductor strength can also influence frontal plane trunk-pelvic motion and knee moments; however, it is unclear how these are inter-related post-amputation.

METHODS

Twenty-four participants with unilateral lower-limb amputation (14 transtibial; 10 transfemoral) and eight uninjured controls walked at 1.3 m/s while full-body biomechanical data were captured. Multiple linear regression and Cohen's f² predicted (P < 0.05) the influences of mediolateral trunk and pelvic ranges of motion and angular accelerations, and bilateral isometric hip abductor strength on peak (intact) knee adduction moment and loading rate.

FINDINGS

There were no group differences in hip strength, peak knee adduction moment or pelvis acceleration (p > 0.06). The combination of hip strength, and mediolateral trunk and pelvic motion did not predict (F_(5,29) = 2.53, p = 0.06, adjusted R² = 0.27, f² = 0.08) peak knee adduction moment. However, the combination of hip strength and trunk and pelvis acceleration predicted knee adduction moment loading rate (F_(7,29) = 3.59, p = 0.008, adjusted R² = 0.45, f² = 0.25), with peak trunk acceleration (β = 0.72, p = 0.008) and intact hip strength (β = 0.78, p = 0.008) significantly contributing to the model.

INTERPRETATION

These data suggest increased hip abductor strength counteracts increased lateral trunk acceleration, concomitantly influencing the rate at which the ground reaction force vector loads the intact knee joint. Persons with lower-limb amputation perhaps compensate for increased intact limb loading by increasing trunk motion, thereby increasing demand on hip abductors to attenuate this preferential loading.

Inter-segmental coordination of the spine is altered during lifting in patients with ankylosing spondylitis: A cross-sectional study

The abnormal inter-segmental coordination of the spine during lifting could be used to monitor disease progression and rehabilitation efficacy in patients with ankylosing spondylitis (AS). This study aimed to compare the inter-segmental coordination patterns and variability of the spine during lifting between patients with AS (n = 9) and control (n = 15) groups.Continuous relative (CRP) and deviation (DP) phases between each segment of the spine (two lumbar and three thorax segments) and lumbosacral joint were calculated. The CRP and DP curves among participants were decomposed into few functional principal components (FPC) via functional principal component analysis (FPCA). The FPC score of CRP or DP of the two groups were compared, and its relationship with the indexes of spinal mobility was investigated.Compared with the control group, the AS patients showed more anti-phase coordination patterns in each relative upper spine segment and lumbosacral joint. In addition, either less or more variation was found in the coordination of each relative lower spine segment and lumbosacral joint during different time periods of lifting for these patients. Some cases were considerably related to spinal mobility.the inter-segmental coordination of the spine was altered during lifting in AS patients to enable movement, albeit inefficient and might cause spinal mobility impairment.

Characterizing and Understanding the Low Back Pain Experience Among Persons with Lower Limb Loss

Objective

This study preliminarily characterizes and compares the impact of lower limb loss and development of chronic low back pain (cLBP) on psychosocial factors, as well as the relationship between these factors and low back pain–related functional disability.

Design

Cross-sectional study.

Methods

Participants were adults, active duty or retired military, with traumatic lower limb loss with and without chronic low back pain. Psychosocial factors and low back pain–related functional disability were measured using common clinical self-report questionnaires. The presence of psychosocial factors was compared between those with and without cLBP using multivariate analysis of covariance (P &lt; 0.05), and correlations determined relationships between psychosocial factors and cLBP-related functional disability.

Results

There were no statistically significant differences among psychosocial factors between those with vs without cLBP (F(4, 13) = 0.81, P = 0.54, η2= 0.19). Employment status (ρ = 0.43, P = 0.02), anxiety (ρ = 0.45, P = 0.04), and kinesiophobia (ρ = 0.47, P = 0.04) were moderately associated with low back pain–related disability.

Conclusions

Psychological (i.e., anxiety) and social (i.e., employment status) factors may influence how persons with traumatic lower limb loss respond to self-reported measures of low back pain–related disability. The findings suggest that the Modified Oswestry Disability Index identifies cLBP-related functional disability in the context of lower limb loss. These results support the interdependence among biological, psychological, and social factors, which should be collectively considered during the development of rehabilitative strategies to treat secondary musculoskeletal conditions within this population.

Trunk-Pelvis motions and spinal loads during upslope and downslope walking among persons with transfemoral amputation

Larger trunk and pelvic motions in persons with (vs. without) lower limb amputation during activities of daily living (ADLs) adversely affect the mechanical demands on the lower back. Building on evidence that such altered motions result in larger spinal loads during level-ground walking, here we characterize trunk-pelvic motions, trunk muscle forces, and resultant spinal loads among sixteen males with unilateral, transfemoral amputation (TFA) walking at a self-selected speed both up ("upslope"; 1.06 ± 0.14 m/s) and down ("downslope"; 0.98 ± 0.20 m/s) a 10-degree ramp. Tri-planar trunk and pelvic motions were obtained (and ranges-of-motion [ROM] computed) as inputs for a non-linear finite element model of the spine to estimate global and local muscle (i.e., trunk movers and stabilizers, respectively) forces, and resultant spinal loads. Sagittal- (p = 0.001), frontal- (p = 0.004), and transverse-plane (p < 0.001) trunk ROM, and peak mediolateral shear (p = 0.011) and local muscle forces (p = 0.010) were larger (respectively 45, 35, 98, 70, and 11%) in upslope vs. downslope walking. Peak anteroposterior shear (p = 0.33), compression (p = 0.28), and global muscle (p = 0.35) forces were similar between inclinations. Compared to previous reports of persons with TFA walking on level ground, 5-60% larger anteroposterior and mediolateral shear observed here (despite ∼0.25 m/s slower walking speeds) suggest greater mechanical demands on the low back in sloped walking, particularly upslope. Continued characterization of trunk motions and spinal loads during ADLs support the notion that repeated exposures to these larger-than-normal (i.e., vs. level-ground walking in TFA and uninjured cohorts) spinal loads contribute to an increased risk for low back injury following lower limb amputation.

Chronic low back pain influences trunk neuromuscular control during unstable sitting among persons with lower-limb loss

BACKGROUND

Persons with unilateral lower-limb loss are at increased risk for developing chronic low back pain. Aberrant trunk and pelvis motor behavior secondary to lower-limb loss potentially alters trunk postural control and increases demands on the trunk musculature for stability. However, it is unclear whether trunk postural control is associated with the presence or chronicity of low back pain within this population.

RESEARCH QUESTION

Is there a potential role of impaired trunk postural control among persons with lower limb loss and chronic low back pain?

METHODS

Two groups of males with unilateral lower-limb loss (n = 18 with chronic low back pain; n = 13 without pain) performed an unstable sitting task. Trunk postural control was characterized using traditional and non-linear measures derived from center-of-pressure time series, as well as trunk kinematics and the ratio of lumbar to thoracic erector spinae muscle activations.

RESULTS

Traditional and non-linear center-of-pressure measures and trunk muscle activation ratios were similar between groups, while participants with chronic low back pain demonstrated greater trunk motion and reduced local dynamic stability.

SIGNIFICANCE

Our results suggest that persons with both lower-limb loss and chronic low back pain exhibit impaired trunk postural control compared to those with limb loss but without pain. Aberrant trunk motor behavior may be a response to altered functional requirements of walking with a prosthesis. An inability to adequately control the trunk could lead to spinal instability and pain in the presence of repetitive exposure to aberrant motor behavior of these proximal structures during everyday activities.

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

OBJECTIVE

To retrospectively investigate trunk-pelvis kinematic outcomes among persons with unilateral transtibial and transfemoral limb loss with time from initial independent ambulation with a prosthesis, while secondarily describing self-reported presence and intensity of low back pain. Over time, increasing trunk-pelvis range of motion and decreasing trunk-pelvis coordination with increasing presence and/or intensity of low back pain were hypothesized. Additionally, less trunk-pelvis range of motion and more trunk-pelvis coordination for persons with more distal limb loss was hypothesized.

DESIGN

Inception cohort with up to 5 repeated evaluations, including both biomechanical and subjective outcomes, during a 1-year period (0, 2, 4, 6, 12 months) after initial ambulation with a prosthesis.

SETTING

Biomechanics laboratory within military treatment facility.

PARTICIPANTS

Twenty-two men with unilateral transtibial limb loss and 10 men with unilateral transfemoral limb loss (N=32).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Triplanar trunk-pelvis range of motion and intersegmental coordination (continuous relative phase) obtained at self-selected (∼1.30m/s) and controlled (∼1.20m/s) walking velocities. Self-reported presence and intensity of low back pain.

RESULTS

An interaction effect between time and group existed for sagittal (P=.039) and transverse (P=.009) continuous relative phase at self-selected walking velocity and transverse trunk range of motion (P=.013) and sagittal continuous relative phase (P=.005) at controlled walking velocity. Trunk range of motion generally decreased, and trunk-pelvis coordination generally increased with increasing time after initial ambulation. Sagittal trunk and pelvis range of motion were always less and frontal trunk-pelvis coordination was always greater for persons with more distal limb loss. Low back pain increased for persons with transtibial limb loss and decreased for persons with transfemoral limb loss following the 4-month time point.

CONCLUSIONS

Temporal changes (or lack thereof) in features of trunk-pelvis motions within the first year of ambulation help elucidate relationships between (biomechanical) risk factors for low back pain after limb loss.

Understanding Low Back Pain in Traumatic Lower Limb Amputees: A Systematic Review

Objective

This systematic review aims to evaluate current literature for the prevalence, causes, and effect of low back pain (LBP) in traumatic lower limb amputees, specifically its association with the kinematics and kinetics of the lumbar spine and lower extremities.

Data Sources

Databases (EMBASE, MEDLINE, Scopus, CINAHL, PsycINFO) were searched systematically for eligible studies from inception to January 2018.

Study Selection

The inclusion terms were synonyms of low back pain, lower limb amputation, and trauma, whereas studies involving nontraumatic amputee populations, single cases, or reviews were excluded. 1822 studies were initially identified, of which 44 progressed to full-text reading, and 11 studies were included in the review.

Data Extraction

Two independent reviewers reviewed the included studies, which were evaluated using a quality assessment tool and the Grades of Recommendation, Assessment, Development and Evaluation system for risk of bias, prior to analyzing results and conclusions.

Data Synthesis

There was an LBP prevalence of 52%-64% in traumatic amputees, compared to 48%-77% in the general amputee population (predominantly vascular, tumor, trauma), attributed to a mixture of biomechanical, psychosocial, and personal factors. These factors determined the presence, frequency, and severity of the pain in the amputees, significantly affecting their quality of life. However, little evidence was available on causality.

Conclusion

The high prevalence of LBP in traumatic amputees highlights the necessity to advance research into the underlying mechanics behind LBP, specifically the spinal kinematics and kinetics. This may facilitate improvements in rehabilitation, with the potential to improve quality of life in traumatic amputees.

Reproducibility and discriminant validity of two clinically feasible measurement methods to obtain coronal plane gait kinematics in participants with a lower extremity amputation

Introduction

Measuring coronal plane gait kinematics of the pelvis and trunk during rehabilitation of participants with a lower extremity amputation is important to detect asymmetries in gait which are hypothesised as associated with secondary complaints. The aim of this study was to test the reproducibility and discriminant validity of a three-dimensional (3-D; inertial measurement units) and a two-dimensional (2-D; video-based) system.

Methods

We tested the test-retest and inter-rater reproducibility of both systems and the 2-D system, respectively, in participants with a lower extremity amputation (group 1) and healthy subjects (group 2). The discriminant validity was determined with a within-group comparison for the 3-D system and with a between-group comparison for both systems.

Results

Both system showed to be test-retest reliable, both in group 1 (2-D system: ICC3.1_agreement 0.52–0.83; 3-D system: ICC3.1_agreement 0.81–0.95) and in group 2 (3-D system: ICC3.1_agreement 0.33–0.92; 2-D system: ICC3.1_agreement 0.54–0.95). The 2-D system was also inter-rater reliable (group 1: ICC2.1_agreement 0.80–0.92; group 2: ICC2.1_agreement 0.39–0.90). The within-group comparison of the 3-D system revealed a statistically significant asymmetry of 0.4°-0.5° in group 1 and no statistically significant asymmetry in group 2. The between-group comparison revealed that the maximum amplitude towards the residual limb (MARL) in the low back (3-D system) and the (residual) limb—trunk angle (2-D system) were significantly larger with a mean difference of 1.2° and 6.4°, respectively, than the maximum amplitude of healthy subjects. However, these average differences were smaller than the smallest detectable change (SDC) of group 1 for both the MARL (SDC_agreement: 1.5°) and the residual limb—trunk angle (SDC_agreement: 6.7°-7.6°).

Conclusion

The 3-D and 2-D systems tested in this study were not sensitive enough to detect real differences within and between participants with a lower extremity amputation and healthy subjects although promising reproducibility parameters for some of the outcome measures.

The relationship between lumbar lordosis angle and low back pain in individuals with transfemoral amputation

BACKGROUND:

Low back pain is a common secondary disabling condition in the transfemoral amputee population. Transfemoral amputees are at risk of excessive lumbar lordosis; it has been suggested that increased lumbar lordosis may be associated with low back pain. However, the relationship between lumbar lordosis angle and low back pain has not yet been studied in this population.

OBJECTIVE:

To determine whether the extent of lumbar lordosis is associated with low back pain in transfemoral amputees.

STUDY DESIGN:

Case-control observational study.

METHODS:

Participants included eight transfemoral amputees without low back pain and nine transfemoral amputees with low back pain. Etiology of amputation was primarily trauma. All participants underwent lateral view radiographs of the lumbar spine, from which lumbar lordosis angle and sacral inclination angle were measured.

RESULTS:

Lumbar lordosis angle mean ± standard deviation was 46.1° ± 12.4° in participants with low back pain and 51.0° ± 12.6° in those without. Sacral inclination angle mean ± standard deviation was 38.3° ± 8.7° in participants with low back pain and 39.1° ± 7.5° in those without. There was no significant difference in lumbar lordosis angle or sacral inclination angle between participants with and without low back pain.

CONCLUSION:

This study suggests that increased lumbar lordosis angle and sacral inclination angle are not significantly associated with low back pain in transfemoral amputees of a primarily traumatic etiology.

CLINICAL RELEVANCE

Low back pain (LBP) is a common, disabling condition in transfemoral amputees. In the clinical setting, increased lumbar lordosis is implicated in LBP. This study does not support an association between increased lumbar lordosis and LBP; further study is needed to understand the increased prevalence of LBP in this population.

Low back pain in persons with lower extremity amputation: a systematic review of the literature

BACKGROUND CONTEXT

Lower extremity amputation (LEA) is associated with an elevated risk for development and progression of secondary health conditions. Low back pain (LBP) is one such condition adversely affecting function, independence, and quality of life.

PURPOSE

The purpose of this study was to systematically review the literature to determine the strength of evidence relating the presence and severity of LBP secondary to LEA, thereby supporting the formulation of empirical evidence statements (EESs) to guide practice and future research.

STUDY DESIGN/SETTING

Systematic review of the literature.

METHODS

A systematic review of five databases was conducted followed by evaluation of evidence and synthesis of EESs.

RESULTS

Seventeen manuscripts were included. From these, eight EESs were synthesized within the following categories: epidemiology, amputation level, function, disability, leg length, posture, spinal kinematics, and osseointegrated prostheses. Only the EES on epidemiology was supported by evidence at the moderate confidence level given support by eight moderate quality studies. The four EESs for amputation level, leg length, posture, and spinal kinematics were supported by evidence at the low confidence level given that each of these statements had some evidence not supporting the statement but ultimately more evidence (and of higher quality) currently supporting the statement. The remaining three EESs that addressed function, disability and osseointegrated prosthetic use were all supported by single studies or had comparable evidence that disagreed with study findings rendering insufficient evidence to support the respective EES.

CONCLUSIONS

Based on the state of the current evidence, appropriate preventative and, particularly, treatment strategies to manage LBP in persons with LEA remain a knowledge gap and an area of future study.

Reference values for gait temporal and loading symmetry of lower-limb amputees can help in refocusing rehabilitation targets

Background

The literature suggests that optimal levels of gait symmetry might exist for lower-limb amputees. Not only these optimal values are unknown, but we also don’t know typical symmetry ratios or which measures of symmetry are essential. Focusing on the symmetries of stance, step, first peak and impulse of the ground reaction force, the aim of this work was to answer to three methodological and three clinical questions. The methodological questions wanted to establish a minimum set of symmetry indexes to study and if there are limitations in their calculations. The clinical questions wanted to establish if typical levels of temporal and loading symmetry exist, and change with the level of amputation and prosthetic components.

Methods

Sixty traumatic, K3-K4 amputees were involved in the study: 12 transfemoral mechanical knee users (TFM), 25 C-leg knee users (TFC), and 23 transtibial amputees (TT). Ninety-two percent used the Ossur Variflex foot. Ten healthy subjects were also included. Ground reaction force from both feet were collected with the Novel Pedar-X. Symmetry indexes were calculated and statistically compared with regression analyses and non-parametric analysis of variance among subjects.

Results

Stance symmetry can be reported instead of step, but it cannot substitute impulse and first peak symmetry. The first peak cannot always be detected on all amputees. Statistically significant differences exist for stance symmetry among all groups, for impulse symmetry between TFM and TFC/TT, for first peak symmetry between transfemoral amputees altogether and TT. Regarding impulse symmetry, 25% of TFC and 43% of TT had a higher impulse on the prosthetic side. Regarding first peak symmetry, 59% of TF and 30% of TT loaded more the prosthetic side.

Conclusions

Typical levels of symmetry for stance, impulse and first peak change with the level of amputation and componentry. Indications exist that C-leg and energy-storage-and-return feet can improve symmetry. Results are suggestive of two mechanisms related to sound side knee osteoarthritis: increased impulse for TF and increased first peak for TT. These results can be useful in clinics to set rehabilitation targets, understand the advancements of a patient during gait retraining, compare and chose components and possibly rehabilitation programs.

Walking speed differentially alters spinal loads in persons with traumatic lower limb amputation

Persons with lower limb amputation (LLA) perceive altered motions of the trunk/pelvis during activities of daily living as contributing factors for low back pain. When walking (at a singular speed), larger trunk motions among persons with vs. without LLA are associated with larger spinal loads; however, modulating walking speed is necessary in daily life and thus understanding the influences of walking speed on spinal loads in persons with LLA is of particular interest here. Three-dimensional trunk-pelvic kinematics, collected during level-ground walking at self-selected (SSW) and two controlled speeds (∼1.0 and ∼1.4 m/s), were obtained for seventy-eight participants: 26 with transfemoral and 26 with transtibial amputation, and 26 uninjured controls (CTR). Using a kinematics-driven, non-linear finite element model of the lower back, the resultant compressive and mediolateral/anteroposterior shear loads at the L5/S1 spinal level were estimated. Peak values were extracted and compiled. Despite walking slower at SSW speeds (∼0.21 m/s), spinal loads were 8-14% larger among persons with transfemoral amputation vs. CTR. Across all participants, peak compressive, mediolateral, and anteroposterior shear loads increased with increasing walking speed. At the fastest (vs. slowest) controlled speed, these increases were respectively 24-84% and 29-77% larger among persons with LLA relative to CTR. Over time, repeated exposures to these increased spinal loads, particularly at faster walking speeds, may contribute to the elevated risk for low back pain among persons with LLA. Future work should more completely characterize relative risk in daily life between persons with vs. without LLA by analyzing additional activities and tissue-level responses.

Aprovechamiento de energía, cinemática y estabilidad en la marcha de un paciente con amputación transfemoral sin abordaje de rehabilitación

Introducción. Los pacientes con amputación de miembros inferiores presentan marcadas asimetrías en la marcha, las cuales pueden aumentar cuando no se cumple con un adecuado proceso de rehabilitación, comprometiendo los objetivos fundamentales de la marcha e incrementando factores de riesgo.Objetivo. Analizar el grado de aprovechamiento de energía mecánica, la estabilidad dinámica y las variables cinemáticas de interés clínico en la marcha de un paciente con amputación transfemoral que no realizó el proceso de rehabilitación.Materiales y métodos. Con base en una reconstrucción 3D, se cuantificaron valores angulares para cadera, rodilla y tobillo y se estimó el intercambio de energía mecánica y la estabilidad dinámica en tres velocidades de marcha diferentes.Resultados. Se observaron variaciones en los parámetros espaciotemporales con el cambio de la velocidad que no son consistentes con los encontrados en otros estudios de amputados. Los valores angulares, principalmente a nivel de rodilla y tobillo, presentan asimetrías que se pueden asociar con una disminución en el aprovechamiento de energía mecánica mientras aumenta la estabilidad en diferentes velocidades.Conclusión. El uso de prótesis en las condiciones en las que fue realizada la evaluación compromete la recuperación de energía mecánica en la marcha del paciente.

Exercise intervention for unilateral amputees with low back pain: study protocol for a randomised, controlled trial

Background

Atraumatic lower limb amputation is a life-changing event for approximately 185,000 persons in the United States each year. A unilateral amputation is associated with rapid changes to the musculoskeletal system including leg and back muscle atrophy, strength loss, gait asymmetries, differential mechanical joint loading and leg length discrepancies. Even with high-quality medical care and prostheses, amputees still develop secondary musculoskeletal conditions such as chronic low back pain (LBP). Resistance training interventions that focus on core stabilization, lumbar strength and dynamic stability during loading have strong potential to reduce LBP and address amputation-related changes to the musculoskeletal system. Home-based resistance exercise programs may be attractive to patients to minimize travel and financial burdens.

Methods/design

This study will be a single-assessor-blinded, pre-post-test randomised controlled trial involving 40 men and women aged 18–60 years with traumatic, unilateral transtibial amputation. Participants will be randomised to a home-based, resistance exercise group (HBRX) or a wait-list control group (CON). The HBRX will consist of 12 weeks of elastic resistance band and bodyweight training to improve core and lumbopelvic strength. Participants will be monitored via Skype or Facetime on a weekly basis. The primary outcome will be pain severity (11-point Numerical Pain Rating Scale; NRS_pain). Secondary outcomes will include pain impact on quality of life (Medical Outcomes Short Form 36, Oswestry Disability Index and Roland Morris Disability Questionnaire), kinematics and kinetics of walking gait on an instrumented treadmill, muscle morphology (muscle thickness of multifidus, transversus abdominis, internal oblique), maximal muscle strength of key lumbar and core muscles, and daily step count.

Discussion

The study findings will determine whether a HBRX program can decrease pain severity and positively impact several physiological and mechanical factors that contribute to back pain in unilateral transtibial amputees with chronic LBP. We will determine the relative contribution of the exercise-induced changes in these factors on pain responsiveness in this population.

Trial registration

ClinicalTrials.gov, ID: NCT03300375. Registered on 2 October 2017.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2362-0) contains supplementary material, which is available to authorized users.

Trunk kinetic effort during step ascent and descent in patients with transtibial amputation using angular momentum separation

BACKGROUND

Patients with transtibial amputation adopt trunk movement compensations that alter effort and increase the risk of developing low back pain. However, the effort required to achieve high-demand tasks, such as step ascent and descent, remains unknown.

METHODS

Kinematics were collected during bilateral step ascent and descent tasks from two groups: 1) seven patients with unilateral transtibial amputation and 2) seven healthy control subjects. Trunk kinetic effort was quantified using translational and rotational segmental moments (time rate of change of segmental angular momentum). Peak moments during the loading period were compared across limbs and across groups.

FINDINGS

During step ascent, patients with transtibial amputation generated larger sagittal trunk translational moments when leading with the amputated limb compared to the intact limb (P=0.01). The amputation group also generated larger trunk rotational moments in the frontal and transverse planes when leading with either limb compared to the healthy group (P=0.01, P<0.01, respectively). During step descent, the amputation group generated larger trunk translational and rotational moments in all three planes when leading with the intact limb compared to the healthy group (P<0.017).

INTERPRETATION

This investigation identifies how differing trunk movement compensations, identified using the separation of angular momentum, require higher kinetic effort during stepping tasks in patients with transtibial amputation compared to healthy individuals. Compensations that produce identified increased and asymmetric trunk segmental moments, may increase the risk of the development of low back pain in patients with amputation.

Impact of Traumatic Lower Extremity Injuries Beyond Acute Care: Movement-Based Considerations for Resultant Longer Term Secondary Health Conditions

Significance: Advances in field-based trauma care, surgical techniques, and protective equipment have collectively facilitated the survival of a historically large number of service members (SMs) following combat trauma, although many sustained significant composite tissue injuries to the extremities, including limb loss (LL) and limb salvage (LS). Beyond the acute surgical and rehabilitative efforts that focus primarily on wound care and restoring mobility, traumatic LL and LS are associated with several debilitating longer term secondary health conditions (e.g., low back pain [LBP], osteoarthritis [OA], and cardiovascular disease [CVD]) that can adversely impact physical function and quality of life. Recent Advances: Despite recent advancements in prosthetic and orthotic devices, altered movement and mechanical loading patterns have been identified among persons with LL and salvage, which are purported risk factors for the development of longer term secondary musculoskeletal conditions and may limit functional outcomes and/or concomitantly impact cardiovascular health. Critical Issues: The increased prevalence of and risk for LBP, OA, and CVD among the relatively young cohort of SMs with LL and LS significantly impact physiological and psychological well-being, particularly over the next several decades of their lives. Future Directions: Longitudinal studies are needed to characterize the onset, progression, and recurrence of health conditions secondary to LL and salvage. While not a focus of the current review, detailed characterization of physiological biomarkers throughout the rehabilitation process may provide additional insight into the current understanding of disease processes of the musculoskeletal and cardiovascular systems.

Long-term outcomes following lower extremity press-fit bone-anchored prosthesis surgery: a 5-year longitudinal study protocol

BACKGROUND

Patients with lower extremity amputation frequently suffer from socket-related problems. This seriously limits prosthesis use, level of activity and health-related quality of life (HRQoL). An additional problem in patients with lower extremity amputation are asymmetries in gait kinematics possibly accounting for back pain. Bone-anchored prostheses (BAPs) are a possible solution for socket-related problems. Knowledge concerning the level of function, activity and HRQoL after surgery is limited. The aims of this ongoing study are to: a) describe changes in the level of function, activity, HRQoL and satisfaction over time compared to baseline before surgery; b) examine potential predictors for changes in kinematics, prosthetic use, walking ability, HRQoL, prosthesis comfort over time and level of stump pain at follow-up; c) examine potential mechanisms for change of back pain over time by identifying determinants, moderators and mediators.

METHODS/DESIGN

A prospective 5-year longitudinal study with multiple follow-ups. All adults, between May 2014 and May 2018, with lower extremity amputation receiving a press-fit BAP are enrolled consecutively. Patients with socket-related problems and trauma, tumour resection or stable vascular disease as cause of primary amputation will be included. Exclusion criteria are severe cognitive or psychiatric disorders. Follow-ups are planned at six-months, one-, two- and five-years after BAP surgery. The main study outcomes follow, in part, the ICF classification: a) level of function defined as kinematics in coronal plane, hip abductor strength, prosthetic use, back pain and stump pain; b) level of activity defined as mobility level and walking ability; c) HRQoL; d) satisfaction defined as prosthesis comfort and global perceived effect. Changes over time for the continuous outcomes and the dichotomized outcome (back pain) will be analysed using generalised estimating equations (GEE). Multivariate GEE will be used to identify potential predictors for change of coronal plane kinematics, prosthetic use, walking ability, HRQoL, prosthesis comfort and for the level of post-operative stump pain. Finally, potential mechanisms for change in back pain frequency will be explored using coronal plane kinematics as a potential determinant, stump pain as moderator and hip abductor strength as mediator.

DISCUSSION

This study may identify predictors for clinically relevant outcome measures.

TRIAL REGISTRATION

NTR5776 . Registered 11 March 2016, retrospectively registered.

Identification of trunk and pelvis movement compensations in patients with transtibial amputation using angular momentum separation

Patients with unilateral dysvascular transtibial amputation (TTA) have a higher risk of developing low back pain than their healthy counterparts, which may be related to movement compensations used in the absence of ankle function. Assessing components of segmental angular momentum provides a unique framework to identify and interpret these movement compensations alongside traditional observational analyses. Angular momentum separation indicates two components of total angular momentum: (1) transfer momentum and (2) rotational momentum. The objective of this investigation was to assess movement compensations in patients with dysvascular TTA, patients with diabetes mellitus (DM), and healthy controls (HC) by examining patterns of generating and arresting trunk and pelvis segmental angular momenta during gait. We hypothesized that all groups would demonstrate similar patterns of generating/arresting total momentum and transfer momentum in the trunk and pelvis in reference to the groups (patients with DM and HC). We also hypothesized that patients with amputation would demonstrate different (larger) patterns of generating/arresting rotational angular momentum in the trunk. Patients with amputation demonstrated differences in trunk and pelvis transfer angular momentum in the sagittal and transverse planes in comparison to the reference groups, which indicates postural compensations adopted during walking. However, patients with amputation demonstrated larger patterns of generating and arresting of trunk and pelvis rotational angular momentum in comparison to the reference groups. These segmental rotational angular momentum patterns correspond with high eccentric muscle demands needed to arrest the angular momentum, and may lead to consequential long-term effects such as low back pain.

Intralimb Coordination Patterns in Absent, Mild, and Severe Stages of Diabetic Neuropathy: Looking Beyond Kinematic Analysis of Gait Cycle

AIM

Diabetes Mellitus progressively leads to impairments in stability and joint motion and might affect coordination patterns, mainly due to neuropathy. This study aims to describe changes in intralimb joint coordination in healthy individuals and patients with absent, mild and, severe stages of neuropathy.

METHODS

Forty-seven diabetic patients were classified into three groups of neuropathic severity by a fuzzy model: 18 without neuropathy (DIAB), 7 with mild neuropathy (MILD), and 22 with moderate to severe neuropathy (SVRE). Thirteen healthy subjects were included as controls (CTRL). Continuous relative phase (CRP) was calculated at each instant of the gait cycle for each pair of lower limb joints. Analysis of Variance compared each frame of the CRP time series and its standard deviation among groups (α = 5%).

RESULTS

For the ankle-hip CRP, the SVRE group presented increased variability at the propulsion phase and a distinct pattern at the propulsion and initial swing phases compared to the DIAB and CTRL groups. For the ankle-knee CRP, the 3 diabetic groups presented more anti-phase ratios than the CTRL group at the midstance, propulsion, and terminal swing phases, with decreased variability at the early stance phase. For the knee-hip CRP, the MILD group showed more in-phase ratio at the early stance and terminal swing phases and lower variability compared to all other groups. All diabetic groups were more in-phase at early the midstance phase (with lower variability) than the control group.

CONCLUSION

The low variability and coordination differences of the MILD group showed that gait coordination might be altered not only when frank evidence of neuropathy is present, but also when neuropathy is still incipient. The ankle-knee CRP at the initial swing phase showed distinct patterns for groups from all degrees of neuropathic severity and CTRLs. The ankle-hip CRP pattern distinguished the SVRE patients from other diabetic groups, particularly in the transitional phase from stance to swing.

Pelvic and Spinal Motion During Walking in Persons With Transfemoral Amputation With and Without Low Back Pain

OBJECTIVE

Low back pain (LBP) is prevalent in people with transfemoral amputation (TFA), imposing significant disability. Yet, limited data exist describing spine kinematics in people with and without LBP despite the suggestion that gait adaptations required to walk with a prosthesis may be associated or causative of LBP. Hence, the purpose of this study was to determine if there were any differences in pelvic and spinal kinematics in persons with TFA with and without LBP.

DESIGN

With the use of a lower body model combined with a regional spine model, pelvic, lumbar, and thoracic kinematics were recorded while walking and compared for participants with TFA with (n = 12) and without (n = 11) self-reported LBP.

RESULTS

Opposite patterns of motion were observed between groups in sagittal and transverse lumbar kinematics but inferential analysis using the χ test was unable to confirm that these differing patterns were independently related to LBP.

CONCLUSIONS

For community ambulators with TFA who report low levels of LBP, differences in lumbar and thoracic motion do not seem to be independently related to LBP. Results may not generalize to those with higher levels of LBP and associated disability.