Biopsychosocial risk factors associated with chronic low back pain after lower limb amputation

Spinal Pathology and Muscle Morphologies with Chronic Low Back Pain and Lower Limb Amputation

INTRODUCTION

Low back pain (LBP) is highly prevalent after lower limb amputation (LLA) and contributes to substantial reductions in quality of life and function. Towards understanding pathophysiological mechanisms underlying LBP after LLA, this article compares lumbar spine pathologies and muscle morphologies between individuals with LBP, with and without LLA.

MATERIALS AND METHODS

We queried electronic medical records of Service members with and without LLA who sought care for LBP at military treatment facilities between January 2002 and May 2020. Two groups with cLBP, one with (n = 15) and one without unilateral transtibial LLA (n = 15), were identified and randomly chosen from a larger sample. Groups were matched by age, mass, and sex. Lumbar muscle morphology, Pfirrmann grades, Modic changes, facet arthrosis, Meyerding grades, and lordosis angle were determined from radiographs and magnetic resonance images available in the medical record. Independent t-tests compared variables between cohorts while multiple regression models determined if intramuscular fat influenced Pfirrmann grades. Chi-square determined differences in presence of spondylolysis and facet arthrosis.

RESULTS

Lordosis angle was larger with LLA (P = 0.01). Spondylolysis was more prevalent with LLA (P = 0.008; 40%) whereas facet arthrosis was similar between cohorts (P = 0.3). Muscle area was not different between cohorts, yet intramuscular fat was greater with LLA (P ≤ 0.05). Intramuscular fat did not influence Pfirrmann grades (P > 0.15).

CONCLUSIONS

Despite similar lumbar muscle size, those with unilateral LLA may be predisposed to progress to symptomatic spondylolisthesis and intramuscular fat. Surgical and/or rehabilitation interventions may mitigate long-term effects of diminished spinal health, decrease LBP-related disability, and improve function for individuals with LLA.

Quality of Life, Physical Activity Participation, and Perceptions of Physical Rehabilitation Among Community-Reintegrated Veterans With Lower Limb Amputation in Sri Lanka: Convergent Parallel Mixed Methods Study

BACKGROUND

Lower limb amputation (LLA) impacts physical activity (PA) participation and quality of life (QoL). To minimize the effects of these challenges, LLA survivors need to have opportunities to engage in appropriately tailored rehabilitation throughout their lives. However, in Sri Lanka, where a 3-decade civil war resulted in trauma-related LLA among young male soldiers, access to rehabilitation was limited to the immediate postinjury period. Developing rehabilitation interventions for these veterans requires an understanding of their current health status and rehabilitation perceptions.

OBJECTIVE

This study was conducted to evaluate the QoL and PA participation of veterans with LLA and explore perceptions of factors influencing their PA participation and expectations for a future community-based physical rehabilitation (CBPR) intervention.

METHODS

This mixed methods study combined a comparative cross-sectional quantitative survey with qualitative semistructured interviews in 5 districts of Sri Lanka. QoL and PA participation were assessed among community-reintegrated veterans with LLA (n=85) and compared with a matched able-bodied cohort (control; n=85) using Mann-Whitney U and Chi-square tests. PA was assessed in terms of metabolic equivalent of task (MET) minutes per week and was computed for walking, moderate-intensity, and vigorous-intensity activities. PA was classified as sufficiently active, low, or sedentary. The design of interview questions was guided by the Theoretical Domains Framework and followed a phenomenological approach. Interviews were conducted with 25 veterans and were analyzed thematically, and the perceptions regarding PA participation and CBPR were codified using the Consolidated Framework for Implementation Research (CFIR).

RESULTS

Based on the quantitative survey findings, scores for both physical (P<.001) and psychological (P<.001) well-being and participation in walking (P=.004) and vigorous-intensity activities (P<.001) were significantly lower among veterans than among controls. A "sedentary" classification was made for 43% (34/79) of veterans and 12% (10/82) of controls. Veterans mostly engaged in moderate-intensity PA inside the house (49/79, 62%) and in the yard (30/79, 38%). Qualitative interviews revealed that barriers to PA exist at individual (eg, comorbidity burden), primary care (eg, absence of community rehabilitation services), and policy levels (eg, limited resources) and facilitators exist primarily at societal (eg, inclusive community) and individual levels (eg, preinjury activity baseline and positive attitudes toward exercise). Expectations regarding CBPR included individualized rehabilitation parameters; functional exercises; and involvement of peers, amputee societies, and community health care providers. The nonresponse rate for interviews was 7% (2/27).

CONCLUSIONS

The findings of reduced PA participation, poor QoL, and physical and psychological impairments among relatively young veterans reveal the long-term impacts of living with LLA in the absence of long-term rehabilitation. Policy-level changes need to be implemented along with behavior-change strategies to promote PA participation and minimize physical inactivity-induced health issues. Veterans' perceptions regarding future CBPR programs were positive and centered on holistic, individualized, and peer-led activities.

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.

Pre-neuromusculoskeletal injury Risk factor Evaluation and Post-neuromusculoskeletal injury Assessment for Return-to-duty/activity Enhancement (PREPARE) in military service members: a prospective, observational study protocol

BACKGROUND

Non-battle related musculoskeletal injuries (MSKI) are one of the primary medical issues diminishing Service member medical readiness. The MSKI problem is challenging because it is difficult to assess all of the factors that increase MSKI risk and influence post-MSKI outcomes. Currently, there are no high-throughput, clinically-feasible, and comprehensive assessments to generate patient-centric data for informing pre- and post-MSKI risk assessment and mitigation strategies. The objective of the "Pre-neuromusculoskeletal injury Risk factor Evaluation and Post-neuromusculoskeletal injury Assessment for Return-to-duty/activity Enhancement (PREPARE)" study is to develop a comprehensive suite of clinical assessments to identify the patient-specific factors contributing to MSKI risks and undesired post-MSKI outcomes.

METHODS

This is a phased approach, multi-center prospective, observational study (ClinicalTrials.gov number: NCT05111925) to identify physical and psychosocial factors contributing to greater MSKI risk and undesired post-MSKI outcomes, and to identify and validate a minimal set of assessments to personalize risk mitigation and rehabilitation strategies. In Phase I, one cohort (n = 560) will identify the physical and psychosocial factors contributing to greater MSKI risks (single assessment), while a second cohort (n = 780) will identify the post-MSKI physical and psychosocial factors contributing to undesired post-MSKI outcomes (serial assessments at enrollment, 4 weeks post-enrollment, 12 weeks post-enrollment). All participants will complete comprehensive movement assessments captured via a semi-automated markerless motion capture system and instrumented walkway, joint range of motion assessments, psychosocial measures, and self-reported physical fitness performance and MSKI history. We will follow participants for 6 months. We will identify the minimum set of clinical assessments that provide requisite data to personalize MSKI risk mitigation and rehabilitation strategies, and in Phase II validate our optimized assessments in new cohorts.

DISCUSSION

The results of this investigation will provide clinically relevant data to efficiently inform MSKI risk mitigation and rehabilitation programs, thereby helping to advance medical care and retain Service members on active duty status.

TRIAL REGISTRATION

PREPARE was prospectively registered on ClinicalTrials.gov (NCT05111925) on 5 NOV 2021, prior to study commencement.

Biomechanical risk factors for knee osteoarthritis and lower back pain in lower limb amputees: protocol for a systematic review

INTRODUCTION

There is a limited research exploring biomechanical risk factors for the development of knee osteoarthritis (KOA) and lower back pain (LBP) between lower limb amputee subgroups, (eg, transtibial amputees (TTA) vs transfemoral amputees (TFA), or TTA dysvascular vs TTA traumatic). Previous reviews have focused primarily on studies where symptoms of KOA or LBP are present, however, due to limited study numbers, this hinders their scope and ability to compare between amputee subgroups. Therefore, the aim of this systematic review is to descriptively compare biomechanical risk factors for developing KOA and LBP between lower limb amputee subgroups, irrespective of whether KOA or LBP was present.

METHODS AND ANALYSIS

This review is currently in progress and screening results are presented alongside the protocol to highlight challenges encountered during data extraction. Five electronic databases were searched (Medline-Web of Science, PubMed, CINAHL, Embase and Scopus). Eligible studies were observational or interventional, reporting biomechanical gait outcomes for individual legs in adult lower limb amputees during flat walking, incline/decline walking or stair ascent/descent. Two reviewers screened for eligibility and level of agreement was assessed using Cohen's Kappa. Data extraction is ongoing. Risk of bias will be assessed using a modified Downs and Black method, and outcome measures will be descriptively synthesised.

ETHICS AND DISSEMINATION

There are no ethical considerations for this systematic review. Due to its scope, results are expected to be published in three separate manuscripts: (1) biomechanical risk factors of KOA between TTA and TFA, relative to non-amputees, (2) biomechanical risk factors of LBP between TTA and TFA, relative to non-amputees and (3) biomechanical risk factors of KOA and LBP between TTA with traumatic or dysvascular causes, relative to non-amputees.

PROSPERO REGISTRATION NUMBER

CRD42020158247.

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.

Lower back kinetic demands during induced lower limb gait asymmetries

BACKGROUND

Gait asymmetries are common in many clinical populations (e.g., amputation, injury, or deformities) and are associated with a high incidence of lower back pain. Despite this high incidence, the impact of gait asymmetries on lower back kinetic demands are not well characterized due to experimental limitations in these clinical populations. Therefore, we artificially and safely induced gait asymmetry during walking in healthy able-bodied participants to examine lower back kinetic demands compared to their normal gait.

RESEARCH QUESTION

Are lower back kinetic demands different during artificially induced asymmetries than those during normal gait?

METHODS

L5/S1 vertebral joint kinetics and trunk muscle forces were estimated during gait in twelve healthy men and women with a musculoskeletal lower back model that uniquely incorporated participant-specific responses using an EMG optimization approach. Five walking conditions were conducted on a force-measuring treadmill, including normal unperturbed "symmetrical" gait, and asymmetrical gait induced by unilaterally altering leg mass, leg length, and ankle joint motion in various combinations. Gait symmetry index and lower back kinetics were compared with repeated-measures ANOVAs and post hoc tests (α = .05).

RESULTS

The perturbations were successful in producing different degrees of step length and stance time gait asymmetries (p < .01). However, lower back kinetic demands associated with asymmetrical gait were similar to, or only moderately different from normal walking for most conditions despite the observed asymmetries.

SIGNIFICANCE

Our findings indicate that the high incidence of lower back pain often associated with gait asymmetries may not be a direct effect of increased lower back demands. If biomechanical demands are responsible for the high incidence of lower back pain in such populations, daily tasks besides walking may be responsible and warrant further investigation.

Are lower back demands reduced by improving gait symmetry in unilateral transtibial amputees?

BACKGROUND

Gait asymmetry and a high incidence of lower back pain are typical for people with unilateral lower limb amputation. A common therapeutic objective is to improve gait symmetry; however, it is unknown whether better gait symmetry reduces lower back pain risk. To begin investigating this important clinical question, we examined a preexisting dataset to explore whether L5/S1 vertebral joint forces in people with unilateral lower limb amputation can be improved with better symmetry.

METHODS

L5/S1 compression and resultant shear forces were estimated in each participant with unilateral lower limb amputation (n = 5) with an OpenSim musculoskeletal model during different levels of guided gait asymmetry. The amount of gait asymmetry was defined by bilateral stance times and guided via real-time feedback. A theoretical lowest L5/S1 force was determined from the minimum of a best-fit quadratic curves of L5/S1 forces at levels of guided asymmetry ranging from -10 to +15%. The forces found at the theoretical lowest force and during the 0% asymmetry level were compared to forces at preferred levels of asymmetry and to those from an able-bodied group (n = 5).

FINDINGS

Results indicated that the forces for the people with unilateral lower limb amputation group at the preferred level of asymmetry were not different then at their 0% asymmetry condition, theoretical lowest L5/S1 forces, or the able-bodied group (all p-values > .23).

INTERPRETATION

These preliminary results challenge the premise that restoring symmetric gait in people with unilateral lower limb amputation will reduce risk of lower back pain.

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.

Deleterious Musculoskeletal Conditions Secondary to Lower Limb Loss: Considerations for Prosthesis-Related Factors

Significance: The intent of this work was to summarize the existing evidence of, and highlight knowledge gaps specific to, prosthetic devices/componentry and training regimes, particularly in the context of the human-device interaction and deleterious musculoskeletal conditions secondary to lower limb loss. Recent Advances: With the recent and evolving technological advancements in prostheses, there are numerous devices available to individuals with lower limb loss. Current literature demonstrates the importance of expanding the knowledge of all prosthetic device-specific factors and the significance of proper prescription, fit, and alignment, along with adequate device-/activity-specific training, to enhance human-device interaction, reduce gait abnormalities and compensatory motions, and as a result, mitigate risk for secondary musculoskeletal conditions. Critical Issues: Inadequate device prescription, fit, alignment, and training are evident owing to the lack of knowledge or awareness of the many device-specific properties and factors, leading to suboptimal use, as well as, biomechanical compensations, which collectively and adversely affect the function, activity level, and overall health of the prosthesis user. Future Directions: To maximize optimal outcomes after lower limb loss, it is essential to better appreciate the factors that affect both prosthesis use and satisfaction, particularly any modifiable factors that might be targeted in rehabilitation interventions such as device prescription, fit/alignment, and training regimes. A better understanding of such device-specific factors will help enhance the human-device interaction and resulting functional performance, thereby reducing secondary musculoskeletal conditions, allowing for the readiness of the fighting force (return-to-duty/redeployment) and/or improved reintegration into civilian society/work, and overall enhancing quality of life after lower limb loss.

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.

The burden of non-specific chronic low back pain among adults in KwaZulu-Natal, South Africa: a protocol for a mixed-methods study

INTRODUCTION

Low back pain (LBP) is a major public health concern, affecting individuals of all age groups across the world. In about 90% of LBP cases, there is no specific cause identified and is, therefore, referred to as non-specific LBP. Due to the non-specific nature of LBP, investigations such as radiological and laboratory investigations are unnecessary and results to delayed diagnosis and improper treatment culminating in LBP progressing into chronic LBP (CLBP). LBP is now the leading cause of disability with a significant socioeconomic burden. Despite all these challenges, CLBP is regarded as a trivial condition in low-and-middle-income countries and remains poorly investigated. The distribution of CLBP in Africa is unclear.

METHODS AND ANALYSIS

The research will be conducted in two phases. The initial phase will be an observational, cross-sectional hospital-based study that will be recruiting 650 participants, to determine the prevalence and risk factors of CLBP. A standardised questionnaire will be used to collect baseline data on the socio-demographic characteristics of participants and other variables of interest (exercise history, occupational posture, level of education and the income status). Disability will be assessed using the Oswestry Disability Questionnaire and the psychological risk factors will be assessed using the Illness-Behaviour Questionnaire (IBQ) and the Fear-Avoidance Belief Questionnaire (FABQ). The second phase will be a retrospective, top-down, prevalence-based cost-of-illness study of the 2018-2019 health records, to estimate the burden of CLBP from the healthcare system's perspective. The SPSS V.25.0 statistical package will be used for data entry and analysis. Statistical analysis will include descriptive statistics by means of graphs and cross tabulations, inferential statistics by means of logistic regression and χ² test. A p value of 0.05 will be deemed statistically significant.

ETHICS AND DISSEMINATION

This protocol was approved by the University of KwaZulu-Natal's Biomedical Research Ethics Committee (Ref. No.: BREC/00000205/2019) and the KwaZulu-Natal Department of Health Research Ethics (Ref. No.: KZ_201909_002). This will be the first LBP cost-of-illness study in the sub-Saharan Africa, and, therefore, it will close these knowledge gaps and present important evidence on the estimated burden of CLBP in this context. The results of this study will be presented to the Department of Health and to the respective stakeholders and decision-makers to discuss the findings and draw their attention to the prioritisation of LBP research, its management, prevention programmes and implementation of educational programme and for the planning of cost-containment policies.

Evolution of Fatigue Damage in the L5-S1 Intervertebral Disc Resulting from Walking Exposures Among Persons with Lower Limb Loss

The risk of fatigue damage within the L5-S1 spinal disc was calculated for a sample of 52 individuals with unilateral limb loss (26 transtibial; 26 transfemoral) and 26 uninjured controls using a non-linear multi-axial fatigue model of the spine motion segments. Time to complete damage was calculated for each participant and walking pace; the influences of walking activity were determined by varying daily step counts. Assuming similar activity across groups (10,000 steps per day), times to failure were not different between persons with and without limb loss (50 [23] vs. 46 [24] years, respectively); walking faster was associated with shorter times to failure. Greater daily step counts similarly decreased time to failure in all groups. While such a similarity in fatigue damage evolution does not necessarily downplay the role of biomechanical factors, it may highlight the important influences of psychosocial factors in the development of low back pain in persons with limb loss. Nevertheless, with additional work to include activities beyond walking, computational damage models can provide a predictive platform for evaluating specific clinical interventions (e.g., behavior modification, movement retraining, prosthetic devices) that are ultimately intended to mitigate physical risk factors for low back pain following limb loss.

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.

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.

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.