Association Between Changes in Subjective and Objective Measures of Mobility in People With Lower Limb Amputations After Inpatient Rehabilitation

The effect of exercise interventions on gait outcomes in subacute and chronic rehabilitation from lower-limb amputation: A systematic review and meta-analysis

Successful walking is a substantial contributor to quality of life in people with lower-limb amputation (PLLA), yet gait difficulties are common. Evidence-based exercise guidelines are necessary for PLLA with different clinical characteristics and at different phases of recovery. To systematically review the literature evaluating effects of exercise interventions on gait outcomes in PLLA at subacute and chronic stages of recovery. Databases MEDLINE, EMBASE, CINAHL, SPORTDiscus, Scopus, and the Cochrane Library were searched (inception to May 10, 2022). Inclusion criteria: randomized controlled trials assessing gait outcomes following exercise intervention; subjects were PLLA ≥18 years of age and used a prosthesis for walking. Meta-analysis using random effects with inverse variance to generate standardized mean differences (SMDs) was completed for primary gait outcomes. Subgroup analysis was conducted for the recovery phase (i.e., subacute and chronic) and level of amputation (e.g., transfemoral and transtibial). Of 16 included articles, 4 studies examined the subacute phase of recovery, whereas 12 examined the chronic phase. Subacute interventions were 30 minutes, 1-7 times/week, for 2-12 weeks. Chronic interventions were 15-60-minutes, 2-3 times/week, for 4-16 weeks. Low-moderate level evidence was shown for a small improvement in the subacute phase (SMD = 0.42, 95% confidence interval [0.06-0.79], I 2 = 46.0%) and a moderate improvement in the chronic phase (SMD = 0.67, 95% confidence interval [0.40-0.94], I 2 = 0.0%) in favor of exercise intervention groups. Multicomponent exercise programs consisting of gait, balance, and strength training are effective at improving gait outcomes in PLLA at subacute and chronic phases of recovery. The optimal duration and frequency of exercise is unclear because of variation between interventions, highlighting an area for future work.

Association between balance confidence and basic walking abilities in people with unilateral transtibial lower-limb amputations: A cross-sectional study

INTRODUCTION

Falls are common for people with lower-limb amputations (PLLA). Low balance confidence is also prevalent, is worse in PLLA not reporting walking automaticity, and is known to negatively affect prosthesis use, social engagement, and quality of life. Moreover, walking with a prosthesis requires continuous attention. Low balance confidence may act as a distractor imposing an additional cognitive load on the already cognitively demanding task of walking with a prosthesis.

METHODS

Adults with unilateral, transtibial amputations were recruited. The Activities-specific Balance Confidence (ABC) scale quantified balance confidence. The L Test assessed basic walking abilities under single-task (ST) (usual) and dual-task (DT) (walking while counting backwards) conditions. The relative change in gait and secondary task performance between conditions (ie, DT cost) was calculated. Separate multivariable linear regressions examined the association of balance confidence on the L Test.

RESULTS

Forty-four PLLA (56.6 ± 12.6 years) participated. An independent association of the ABC to ST ( P < 0.001, R 2 = 0.56) and DT ( P = 0.008, R 2 = 0.43) L Test performance was observed. A 1% ABC increase was related with a 0.24 (95% confidence interval, 0.35-0.14) and 0.23 (95% confidence interval, 0.39-0.06) second reduction with the ST and DT L Test, respectively. No association to DT cost was observed.

CONCLUSIONS

Balance confidence influences basic walking abilities yet does not modulate the added cognitive load associated with DT. Interventions that address balance confidence may be beneficial throughout rehabilitation. This research is novel and offers the possibility for alternative avenues for focus in rehabilitation and falls prevention in a population at high risk for falls.

Development of an item bank for measuring prosthetic mobility in people with lower limb amputation: The Prosthetic Limb Users Survey of Mobility (PLUS-M)

BACKGROUND

Achieving mobility with a prosthesis is a common post-amputation rehabilitation goal and primary outcome in prosthetic research studies. Patient-reported outcome measures (PROMs) available to measure prosthetic mobility have practical and psychometric limitations that inhibit their use in clinical care and research.

OBJECTIVE

To develop a brief, clinically meaningful, and psychometrically robust PROM to measure prosthetic mobility.

DESIGN

A cross-sectional study was conducted to administer previously developed candidate items to a national sample of lower limb prosthesis users. Items were calibrated to an item response theory model and two fixed-length short forms were created. Instruments were assessed for readability, effective range of measurement, agreement with the full item bank, ceiling and floor effects, convergent validity, and known groups validity.

SETTING

Participants were recruited using flyers posted in hospitals and prosthetics clinics across the United States, magazine advertisements, notices posted to consumer websites, and direct mailings.

PARTICIPANTS

Adult prosthesis users (N = 1091) with unilateral lower limb amputation due to traumatic or dysvascular causes.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Candidate items (N = 105) were administered along with the Patient Reported Outcome Measurement Information System Brief Profile, Prosthesis Evaluation Questionnaire - Mobility Subscale, and Activities-Specific Balance Confidence Scale, and questions created to characterize respondents.

RESULTS

A bank of 44 calibrated self-report items, termed the Prosthetic Limb Users Survey of Mobility (PLUS-M), was produced. Clinical and statistical criteria were used to select items for 7- and 12-item short forms. PLUS-M instruments had an 8th grade reading level, measured with precision across a wide range of respondents, exhibited little-to-no ceiling or floor effects, correlated expectedly with scores from existing PROMs, and differentiated between groups of respondents expected to have different levels of mobility.

CONCLUSION

The PLUS-M appears to be well suited to measuring prosthetic mobility in people with lower limb amputation. PLUS-M instruments are recommended for use in clinical and research settings.

Postamputation Cognitive Impairment Is Related to Worse Perceived Physical Function Among Middle-Aged and Older Prosthesis Users

OBJECTIVE

To compare characteristics between middle-aged and older prosthesis users with and without cognitive impairment and determine whether cognitive impairment contributes to variability in perceived physical function.

DESIGN

Cross-sectional, observational study SETTING: General community.

PARTICIPANTS

Adults 45 years or older, at least 1-year post lower limb amputation (LLA) who were walking independently with a prosthesis (N=119).

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURES

We identified cognitive impairment using an education-adjusted Telephone Interview for Cognitive Status-modified score. Perceived physical function was measured using the Prosthesis Mobility Questionnaire.

RESULTS

Of 119 participants (mean age, 62.6±8.2 years; male: 89.1%; vascular etiology: 82.4%; years since amputation: 4.9±4.7 years), 28 (23.5%) had cognitive impairment. Compared with participants without cognitive impairment, those with cognitive impairment were more likely to use an assistive device (60.7% vs 25.3%, P=.002); were older (66.3±7.3 vs 61.5±8.1 years, P=.006) and had more chronic conditions (7.1±3.4 vs 5.4±2.5, P=.004), more depressive symptoms (6.6±5.1 vs 4.2±3.8, P=.008), and worse perceived physical function (2.0±0.6 vs 2.6±0.7, P<.001). Using backward stepwise linear regression, we found that participants with cognitive impairment had worse perceived physical function (standardized parameter estimate [β]=-0.15, P=.02), even after adjusting for depressive symptoms (β=-0.31, P<.001), prosthesis satisfaction (β=0.34, P<.001), number of chronic conditions (β=-0.19, P=.006), and assistive device use (βcane=0.01, P=.93; βother=-0.20, P=.003). Together, these variables explained 59% of perceived physical function variability.

CONCLUSIONS

Cognitive impairment is common and associated with worse perceived physical function post LLA, even after controlling for physical and mental health differences. Tailored rehabilitation interventions may be needed to improve perceived physical function in prosthesis users with cognitive impairment.

The subjective minimal important change for the Six Spot Step Test in people with multiple sclerosis - The Danish MS Hospitals Rehabilitation study

INTRODUCTION

The Six Spot Step Test has shown good psychometric properties in terms of validity and reliability in people with multiple sclerosis. Yet, the responsiveness and minimal important change are unknown. The objective was to investigate the responsiveness of the Six Spot Step Test against the perceived change of walking limitations and establish estimates for the minimal important change in people with multiple sclerosis.

METHODS

The Six Spot Step Test was performed before and after four weeks of specialised multidisciplinary inpatient rehabilitation by 142 adults with mild to severe multiple sclerosis. Responsiveness was determined based on anchor- and distribution-based methods, using the Multiple Sclerosis Walking Scale-12 as external criterion. In a supplementary analysis, the Six-Minute Walking Test was used as an external criterion.

RESULTS

The correlation between the baseline (r = 0.56, p < 0.01) and discharge (r = 0.55, p < 0.01) Multiple Sclerosis Walking Scale-12 and Six Spot Step Test scores were acceptable. Furthermore, the change scores were weakly associated (r = 0.1, p = 0.27). This trend was similar for the Six-Minute Walking Test when used as anchor. The smallest detectable change was estimated to 1.7 seconds. An improvement in the Six Spot Step Test exceeding 2.1 (95% CI - 0.9 to 5.0) sec and 4.9 (95% CI 1.2-8.6) sec may be considered clinically important on a group level based on the Multiple Sclerosis Walking Scale-12 and the Six-Minute Walking Test, respectively.

CONCLUSION

In a sample of mild to severely disabled people with multiple sclerosis, the Six Spot Step Test showed fair responsiveness against a subjective and objective criterion, indicating a minimal important change between ≥ 2.1 and ≥ 4.9 seconds, respectively. However, a weak association between the change in the Six Spot Step Test and the subjective and objective external criterion calls for cautious interpretation. Hence, the results should be further verified against a valid external criterion.

Evaluation of an articulated passive ankle-foot prosthesis

Background

Current ankle prostheses for people with unilateral transtibial amputation (TTA) or transfemoral amputation (TFA) are unable to mimic able-bodied performance during daily activities. A new mechanical ankle–foot prosthesis was developed to further optimise the gait of people with a lower-limb amputation. This study aimed to evaluate the Talaris Demonstrator (TD) during daily activities by means of performance-related, physiological and subjective outcome measures.

Materials and methods

Forty-two participants completed a protocol assessing performance and functional mobility with their current prosthesis and the TD. The protocol comprised the L-test, 2 min of stair climbing, 2 min of inclined treadmill walking, 6 min of treadmill walking at 3 different speeds in consecutive blocks of 2 min, and a 3-m Backward Walk test (3mBWT). Heart rate was measured during each task, and oxygen uptake was collected during all tasks except for the L-test and 3mBWT. Time of execution was recorded on the L-test and 3mBWT, and the rate of perceived exertion (score = 6–20), fatigue and comfort (score = 0–100) were assessed after each task. Paired sample t-tests and Wilcoxon Signed-rank tests were performed to compare outcomes between prosthetic devices. Benjamini–Hochberg corrections were applied to control for multiple comparisons with a level of significance set at α = 0.05.

Results

Subjects with a TTA (N = 28) were faster with their current prosthesis compared to the TD on the L-test and 3mBWT (p = 0.005). In participants with a TFA (N = 14), we observed a tendency towards a higher heart rate during the L-test and towards increased comfort during inclined walking, with the TD compared to the participants’ current prosthetic device (0.05 < p < 0.10). Further, no significant results were observed.

Conclusion

The Talaris Demonstrator is a novel state-of-the-art passive ankle–foot prosthesis for both people with a TTA and TFA. Subjective measures indicate the added value of this device, while overall task performance and intensity of effort do not differ between the Talaris Demonstrator and the current prosthesis. Further investigations unravelling both acute and more prolonged adaptations will be conducted to evaluate the TD more thoroughly.

Association Between Balance Self-efficacy and Walking Ability in Those With New Lower Limb Amputations

BACKGROUND

A relationship between walking ability and self-efficacy has been demonstrated in various rehabilitation patient populations. In experienced prosthetic ambulators, walking ability is related to self-efficacy of balance, however, this relationship has not been quantified for those with newly acquired lower limb amputations (LLA).

OBJECTIVES

To investigate the association between walking performance (objective) and self-reported walking abilities (subjective) on balance self-efficacy in those with LLA.

METHODOLOGY

Cross-sectional study of 27 people (17 men; mean age=63.57±9.33) at discharge from inpatient prosthetic rehabilitation for first major unilateral LLA. Individuals completed 6m straight path walking and the L-Test under single- and dual-task conditions. The Prosthesis Evaluation Questionnaire (PEQ) was administered, and the Ambulation subscale provided subjective measures of walking ability. A single PEQ question on satisfaction with walking (16B) was also used as a proxy for subjective walking ability. The Activities-specific Balance Confidence Scale measured balance self-efficacy. Multivariable linear regression was used to evaluate the strength of association between walking ability (objective and subjective) and balance self-efficacy (dependent variable).

FINDINGS

Walking velocity on the 6m straight path under single-task (p=0.011) and dual-task conditions (p=0.039), the single-task L-Test (p=0.035) and self-reported satisfaction with walking (p=0.019) were associated with self-efficacy of balance.

CONCLUSIONS

Objective measures of walking ability that were independently associated with balance self-efficacy included straight path walking velocity under single and dual-task conditions and the single-task L-Test. Satisfaction with walking was also associated with balance self-efficacy. This highlights the interplay between physical and psychological factors during rehabilitation. More research in the area of self-efficacy and walking ability is needed to establish self-efficacy as a target during prosthetic rehabilitation for those with LLA.

Measurement properties of the L Test with fast walking speed in patients after lower limb amputation in initial prosthetic training phase

The L Test is a clinical mobility test used in patients after lower limb amputation. To assess dynamic balance, it should be performed with fast walking speed. Its measurement properties in the initial prosthetic training phase are not known yet. The objective of the study was to establish intra- and interrater reliability, concurrent and discriminant validity, minimal detectable change, effect size between the rehabilitation time points and ceiling effect of the L Test with fast walking speed in patients after lower limb amputation in initial prosthetic training phase. The study included 36 inpatients aged 19-86 years who were provided with a prosthesis for the first time. They were assessed repeatedly with the L Test, Ten-meter Walk Test and 6-min Walk Test. The intra- (ICC3, k = 0.94) and interrater reliability (ICC2, k = 0.96) of the L Test were excellent. Correlations with the walking tests were very good (r = 0.75-0.86). Regression analysis with respect to the level of lower limb amputation showed a linear relationship with other variables (R2 = 0.55). Influences of age, cause of lower limb amputation and walking aid were statistically significant. The L Test was responsive to change after two weeks of prosthetic training (Cohen's d = 1.21). No ceiling effect was identified. The L Test with fast walking speed is a feasible, reliable, valid, and responsive measure of basic mobility skills in patients after lower limb amputation in the initial prosthetic training phase.