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Differences in Measures of Strength and Dynamic Balance Among Individuals With Lower-Limb Loss Classified as Functional Level K3 Versus K4

Beisheim, Emma Haldane PT, DPT; Horne, John Robert CPO; Pohlig, Ryan Todd PhD; Sions, Jaclyn Megan PhD, PT, DPT

American Journal of Physical Medicine & Rehabilitation: September 2019 - Volume 98 - Issue 9 - p 745–750
doi: 10.1097/PHM.0000000000001183
Original Research Articles

Objective For individuals with lower-limb loss, functional mobility (ie, K-level) classification can be subjective. Performance-based outcome measures improve the objectivity of K-level assignment; therefore, this study aimed to determine differences in functional strength– and dynamic balance–based outcome measures performance between K3- and K4-classified adults with lower-limb loss.

Design Prosthetists used subjective information and prosthetic componentry to determine K-levels before outcome measures testing for adults with a unilateral transtibial (n = 50) or transfemoral amputation (n = 17). Outcome measures (ie, 5-Times Sit-to-Stand Test, Figure-of-8 Walk Test, 360-degree Turn Test, and modified Four-Square Step Test) were administered by a blinded examiner. Univariate analyses of variance were used to evaluate between-subgroup differences.

Results K4-classified participants with a unilateral transfemoral amputation performed better on all outcome measures when compared with K3-classified peers, whereas K4-classified individuals with a transtibial amputation performed better on the modified Four-Square Step Test compared with K3-classified peers (P < 0.050).

Conclusions K4-classified individuals demonstrated greater lower-limb functional strength and better dynamic balance compared with K3-classified peers. To assist with K-level classification, clinicians should consider selecting outcome measures that objectively differentiate between K-levels (ie, modified Four-Square Step Test for those with a unilateral transtibial or transfemoral amputation; 5-Times Sit-to-Stand Test, Figure-of-8 Walk Test, and 360-degree Turn Test for those with a transfemoral amputation).

From the University of Delaware, Department of Physical Therapy, Delaware Limb Loss Studies, Newark, Delaware (EHB, JMS); Independence Prosthetics-Orthotics, Inc, Newark, Delaware (JRH); and University of Delaware, Biostatistics Core Facility, Newark, Delaware (RTP).

All correspondence should be addressed to: Jaclyn Megan Sions, PhD, PT, DPT, 540 S College Ave, Suite 210JJ, Newark, DE 19713.

J.M.S. is a consultant for Independence Prosthetics-Orthotics, Inc.

The study was supported by the National Institutes of Health (Grant Numbers RO3HD088668 and 5T32HD007490-17).

The study has been accepted for presentation as a platform presentation at the American Academy of Orthotists and Prosthetists (AAOP) Annual Meeting, Orlando, FL, March 6–9, 2019.

Emma Haldane Beisheim is in training.

Financial disclosure statements have been obtained, and no conflicts of interest have been reported by the authors or by any individuals in control of the content of this article.

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Online date: April 4, 2019

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