Dataset Information

Using Clinical Balance Tests to Assess Fall Risk among Established Unilateral Lower Limb Prosthesis Users: Cutoff Scores and Associated Validity Indices.

ABSTRACT:

Background

Clinicians are routinely required to make decisions about fall risk among lower limb prosthesis (LLP) users. These decisions can be guided by standardized clinical balance tests but require population- and test-specific cutoff scores and validity indices to categorize individuals as probable fallers or nonfallers on the basis of test performance. Despite the importance of cutoff scores and validity indices to clinical interpretation of clinical balance test scores, they are rarely reported for LLP users. In their absence, clinicians cannot use results from clinical balance tests to assess the likelihood of a fall by any one patient.

Objective

Derive cutoff scores, and associated validity indices, for clinical balance tests administered to established unilateral LLP users.

Design

Cross-sectional study.

Setting

Outpatient clinic and research laboratory.

Participants

Established ambulatory unilateral transtibial and transfemoral prosthesis users (n?=?40).

Intervention

Not applicable.

Main outcome measure(s)

Optimal cutoff scores and related validity indices (ie, area under the curve, sensitivity, specificity, likelihood ratios) were computed for five balance tests, the activities-specific balance confidence scale (ABC), timed up and go (TUG), four square step test (FSST), Berg balance scale (BBS), and narrowing-beam walking test (NBWT).

Results

Cutoff scores were identified for the NBWT (?.43/1.0), TUG (?8.17?seconds], FSST (?8.49 seconds), BBS (?50.5/56), and ABC (?80.2/100). Validity indices (ie, area under the curve, sensitivity, specificity, and likelihood ratios) for the NBWT, TUG, and FSST had greater diagnostic accuracy and provided more information about the probability of a fall than those for the BBS or ABC.

Conclusion

Performance above or below identified cutoff scores for the NBWT, FSST, and TUG provides information about potentially important shifts in the probability of falling among established unilateral LLP users. These results can serve as initial benchmarks to reduce uncertainty surrounding fall risk assessment in established unilateral LLP users but require future prospective evaluation.

Level of evidence

III.

SUBMITTER: Sawers A

PROVIDER: S-EPMC6755076 | biostudies-literature | 2020 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Using Clinical Balance Tests to Assess Fall Risk among Established Unilateral Lower Limb Prosthesis Users: Cutoff Scores and Associated Validity Indices.

Sawers Andrew A Hafner Brian J BJ

PM & R : the journal of injury, function, and rehabilitation 20190503 1

<h4>Background</h4>Clinicians are routinely required to make decisions about fall risk among lower limb prosthesis (LLP) users. These decisions can be guided by standardized clinical balance tests but require population- and test-specific cutoff scores and validity indices to categorize individuals as probable fallers or nonfallers on the basis of test performance. Despite the importance of cutoff scores and validity indices to clinical interpretation of clinical balance test scores, they are ra ...[more]

PMID: 30900830

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Project description:BackgroundHip muscles play a prominent role in compensating for the loss of ankle and/or knee muscle function after lower limb amputation. Despite contributions to walking and balance, there is no consensus regarding hip strength deficits in lower limb prosthesis (LLP) users. Identifying patterns of hip muscle weakness in LLP users may increase the specificity of physical therapy interventions (i.e., which muscle group(s) to target), and expedite the search for modifiable factors associated with deficits in hip muscle function among LLP users. The purpose of this study was to test whether hip strength, estimated by maximum voluntary isometric peak torque, differed between the residual and intact limbs of LLP users, and age- and gender-matched controls.MethodsTwenty-eight LLP users (14 transtibial, 14 transfemoral, 7 dysvascular, 13.5 years since amputation), and 28 age- and gender-matched controls participated in a cross-sectional study. Maximum voluntary isometric hip extension, flexion, abduction, and adduction torque were measured with a motorized dynamometer. Participants completed 15 five-second trials with 10-s rest between trials. Peak isometric hip torque was normalized to body mass × thigh length. A 2-way mixed-ANOVA with a between-subject factor of leg (intact, residual, control) and a within-subject factor of muscle group (extensors, flexors, abductors, adductors) tested for differences in strength among combinations of leg and muscle group (α = 0.05). Multiple comparisons were adjusted using Tukey's Honest-Difference.ResultsA significant 2-way interaction between leg and muscle group indicated normalized peak torque differed among combinations of muscle group and leg (p < 0.001). A significant simple main effect of leg (p = 0.001) indicated peak torque differed between two or more legs per muscle group. Post-hoc comparisons revealed hip extensor, flexor, and abductor peak torque was not significantly different between the residual and control legs (p ≥ 0.067) but torques in both legs were significantly greater than in the intact leg (p < 0.001). Peak hip abductor torque was significantly greater in the control and residual legs than the intact leg (p < 0.001), and significantly greater in the residual than control leg (p < 0.001).ConclusionsOur results suggest that it is the intact, rather than the residual limb, that is weaker. These findings may be due to methodological choices (e.g., normalization), or biomechanical demands placed on residual limb hip muscles. Further research is warranted to both confirm, expand upon, and elucidate possible mechanisms for the present findings; and clarify contributions of intact and residual limb hip muscles to walking and balance in LLP users.Clinical trial registrationN/A.

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Dataset Information

Using Clinical Balance Tests to Assess Fall Risk among Established Unilateral Lower Limb Prosthesis Users: Cutoff Scores and Associated Validity Indices.

Background

Objective

Design

Setting

Participants

Intervention

Main outcome measure(s)

Results

Conclusion

Level of evidence

Publications

Using Clinical Balance Tests to Assess Fall Risk among Established Unilateral Lower Limb Prosthesis Users: Cutoff Scores and Associated Validity Indices.

Similar Datasets

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