Lower limb joint moment during walking in water.
OBJECTIVE
Walking in water is a widely used rehabilitation method for patients with orthopedic disorders or arthritis, based on the belief that the reduction of weight in water makes it a safer medium and prevents secondary injuries of the lower-limb joints. To our knowledge, however, no experimental data on lower-limb joint moment during walking in water is available. The aim of this study was to quantify the joint moments of the ankle, knee, and hip during walking in water in comparison with those on land.


METHODS
Eight healthy volunteers walked on land and in water at a speed comfortable for them. A video-motion analysis system and waterproof force platform were used to obtain kinematic data and to calculate the joint moments.


RESULTS
The hip joint moment was shown to be an extension moment almost throughout the stance phase during walking in water, while it changed from an extension- to flexion-direction during walking on land. The knee joint moment had two extension peaks during walking on land, whereas it had only one extension peak, a late one, during walking in water. The ankle joint moment during walking in water was considerably reduced but in the same direction, plantarflexion, as that during walking on land.


CONCLUSIONS
The joint moments of the hip, knee, and ankle were not merely reduced during walking in water; rather, inter-joint coordination was totally changed.
Department of Motor Dysfunction, Research Institute, National Rehabilitation Center for Persons with Disabilities, Saitama, Japan. tasuku@rehab.go.jp
Tasuku
T
Miyoshi
Takashi
T
Shirota
Shin-Ichiro
S
Yamamoto
Kimitaka
K
Nakazawa
Masami
M
Akai
D000328:Adult; D000843:Ankle Joint / Q000502:physiology*; D006621:Hip Joint / Q000502:physiology*; D006801:Humans; D007719:Knee Joint / Q000502:physiology; D008297:Male; D016059:Range of Motion, Articular / Q000502:physiology; D016138:Walking / Q000502:physiology*; D014867:Water
D014867:Water