title: Isokinetic trunk and knee muscle strengths and gait performance in walking patients with T-cell lymphotropic virus type 1-associated myelopathy/ tropical spastic paraparesis (HAM/TSP).
abstract: The aim of this study was to investigate the isokinetic trunk and knee muscle strengths, and examine the clinical relevance of dynamic muscle strengths and gait performance in walking patients with human T-cell lymphotropic virus type 1-associated myelopathy/ tropical spastic paraparesis (HAM/TSP). Thirteen patients with HAM/TSP (8 females and 5 males, aged 38-76) and 13 sex- and age-matched healthy control subjects participated in the study. We assessed gait speed, stride length, cadence; and maximal isokinetic torque of trunk and knee extensors and flexors at 30°/s, 60°/s and 90°/s using a Biodex System 3 dynamometer. Furthermore, we calculated the isokinetic trunk extensor/flexor (E/F) and hamstrings/quadriceps (H/Q) strength ratios (parameter of the muscle strength balance about the trunk and knee joint). Compared with the age-matched controls, the patients with HAM/TSP had significantly reduced gait speed, stride length and cadence (P < 0.05). Peak torque values related to body weight (PTBW) were significantly reduced, especially for the knee flexors (P < 0.05). For the knee extensors, the PTBW values were significantly reduced at an increased angular velocity (P < 0.05). The PTBW of knee flexors was positively correlated with gait speed and cadence in the patients with HAM/TSP. The H/Q ratio but not E/F ratio was significantly decreased compared with the control. Our results indicated that the isokinetic trunk and knee muscle performance had reduced from the ambulatory stage, and suggested the deterioration in knee muscle performance to be associated with gait disturbance in walking HAM/TSP patients.
authors: School of Health Sciences, Faculty of Medicine, Kagoshima University, 8-35-1, Sakuragaoka, Kagoshima, 890-8544, Japan.
authors: Masashi
authors: M
authors: Miyazaki
authors: School of Health Sciences, Faculty of Medicine, Kagoshima University, 8-35-1, Sakuragaoka, Kagoshima, 890-8544, Japan.
authors: Harutoshi
authors: H
authors: Sakakima
authors: School of Health Sciences, Faculty of Medicine, Kagoshima University, 8-35-1, Sakuragaoka, Kagoshima, 890-8544, Japan.
authors: Tatsushi
authors: T
authors: Goto
authors: School of Health Sciences, Faculty of Medicine, Kagoshima University, 8-35-1, Sakuragaoka, Kagoshima, 890-8544, Japan.
authors: Ryoji
authors: R
authors: Kiyama
authors: Department of Neurology and Geriatric, Kagoshima University.
authors: Toshio
authors: T
authors: Matsuzaki
authors: Department of Orthopaedic Surgery, Kagoshima University.
authors: Kosei
authors: K
authors: Ijiri
authors: School of Health Sciences, Faculty of Medicine, Kagoshima University, 8-35-1, Sakuragaoka, Kagoshima, 890-8544, Japan.
authors: Yoshihiro
authors: Y
authors: Yoshida
keywords: HAM/TSP; agonist/antagonist ratio; isokinetic muscle strength; muscle weakness