Jpn J Compr Rehabil Sci Vol 6, 2015 137 ABSTRACT Tanikawa H, Mukaino M, Matsuda F, Inagaki K, Ohtsuka K, Kagaya H, Saitoh E, Kanada Y. Influence of contralateral lower limb stabilization on hip abductor muscle strength measured by Hand-Held Dynamometer. Jpn J Compr Rehabil Sci 2015; 6: 137- 142. Objective: To investigate the influence of contralateral lower limb function on hip abductor muscle strength using a hand-held dynamometer. Method: Thirty healthy subjects and fifty-nine hemiplegic patients participated in this study. Hip abductor muscle strength was measured in the supine position with or without stabilization of the contralateral lower limb (stabilizing vs. nonstabilizing method, respectively). Strength as measured using both methods was compared on each side for the lower limb and correlation coefficients for the two methods were calculated. In addition, correlation coefficients between measurements of strength using the two methods on both sides were calculated. In the hemiplegic patients, multiple regression analysis was performed using the strength on the affected side as the dependent variable, and the strength on the unaffected side and the degree of paralysis as independent variables. Results: Strength measured using the stabilizing method was significantly lower than when using the nonstabilizing method. The correlation between the strength on both sides was high in the healthy subjects despite contralateral lower limb stabilization, but low in the hemiplegic patients when using the nonstabilizing method. The strength on the affected side was strongly influenced by the unaffected lower limb function in measurements using the stabilizing method. Discussion: Measurements of hip abduction strength when using the stabilizing method are not an accurate reflection of the strength due to the influence of contralateral lower limb function. Key words: hip abductor muscle strength, Hand-held dynamometer (HHD), hemiplegia, contralateral lower limb, stabilization Introduction In hemiplegic stroke patients, hip abductor muscle strength on the affected and unaffected sides correlates significantly with comfortable gait velocity, gait independence, and continuous gait distance [1]. Furthermore, in patients with unilateral coxarthrosis, the hip abductor muscle strength on the affected side is one of the determinants of maximum gait velocity [2] and the strength on both sides is correlated with gait speed [3]. In patients following total knee arthroplasty, hip abductor muscle strength on both sides strongly affects comfortable gait velocity and the time needed to climb stairs and to stand up [4]. For these reasons, hip abductor muscle strength is an important indicator of walking ability for predicting recovery potential. Many earlier investigations employed a Hand-held dynamometer (HHD) to quantitatively measure muscle strength. Although there is no standardized method for measuring hip abductor muscle strength using an HHD [5-12], high intra-rater reliability was reported when measuring strength in the supine position with or without stabilization of the contralateral lower limb [5-7]. In healthy subjects, strength measured with stabilization of the contralateral lower limb was lower than without stabilization [13, Japanese Journal of Comprehensive Rehabilitation Science (2015) Original Article Influence of contralateral lower limb stabilization on hip abductor muscle strength measured by Hand-Held Dynamometer Hiroki Tanikawa, RPT, MS, 1 Masahiko Mukaino, MD, DMSc, 2 Fumihiro Matsuda, RPT, MS, 1 Keisuke Inagaki, RPT, MS, 3 Kei Ohtsuka, RPT, DMSc, 1 Hitoshi Kagaya, MD, DMSc, 2 Eiichi Saitoh, MD, DMSc, 2 Yoshikiyo Kanada, RPT, DMSc 1 1 Faculty of Rehabilitation, School of Health Sciences, Fujita Health University, Toyoake, Aichi, Japan 2 Department of Rehabilitation Medicine I, School of Medicine, Fujita Health University, Toyoake, Aichi, Japan 3 Department of Rehabilitation, Fujita Health University Hospital, Toyoake, Aichi, Japan Correspondence: Hiroki Tanikawa, RPT, MS Faculty of Rehabilitation, School of Health Sciences, Fujita Health University, 1-98 Dengakugakubo, Kutsukake, Toyoake, Aichi 470-1192, Japan. E-mail: tanikawa@fujita-hu.ac.jp Accepted: November 18, 2015 Conflict of interest: The authors have no conflict of interest in this study. This study did not receive financial support.