Senda, Masuo

Muscle power in the lower extremities and body sway were measured in 57 healthy young women volunteers in their 20's. Body sway was measured with a stabilimeter for 30 sec during two-leg standing, and for 10 sec during one-leg standing with the eyes open or closed, alternating between right and left legs (5 times each). The measured parameters of body sway were locus length per time unit, locus length per environmental area, environmental area, rectangle area, root mean square area, and the ratio of sway with eyes closed to sway with eyes open. Knee flexor and extensor power and toe flexor and abductor power were the measures representing lower extremity muscle power. The increase in sway with the eyes closed was more marked during one-leg standing than two-leg standing, as expected. We found that 36 of 57 subjects (62%) were unable to maintain one-leg standing with their eyes closed, and this failure correlated with marked body sway (P = 0.0086). Many subjects had one leg that was classified as stable and the other leg classified as unstable. Clearly, testing of both legs alternately with eyes closed is necessary to measure the full range of sway in subjects. Lower extremity muscle power did not appear to be the dominant factor in maintaining balance in these young subjects.

Rheumatoid arthritis (RA) is often associated with deformities of the feet, and foot pain often arises in the talonavicular joint of patients with RA. The object of this study was to assess the relationship between magnetic resonance imaging (MRI) findings of the talonavicular joint and walking ability. The subjects were 35 RA patients (10 feet in 5 males and 56 feet in 30 females) aged 34-87 years (mean: 70 years +/- 12.1), with a disease duration from 1-54 years (mean: 14 years +/- 12.1). MRI findings were classified as follows: Grade 1, almost normal; Grade 2, early articular destruction; Grade 3, moderate articular destruction; Grade 4, severe articular destruction; and Grade 5, bony ankylosis dislocation. Walking ability was classified into one of 9 categories ranging from normal gait to bedridden status according to the system of Fujibayashi. As the grade of MRI images became higher the walking ability decreased, and these parameters showed a correlation by Spearman's rank correlation coefficient analysis (P = 0.003). Thus, in the present cohort group of patients with RA, the deterioration of walking ability increased with the severity of destruction of the talonavicular joint.

In order to examine fatigue of the knee flexor and extensor muscles and to investigate the characteristics of muscular fatigue in different sports, a Cybex machine was used to measure muscle fatigue and recovery during isokinetic knee flexion and extension. Eighteen baseball players, 12 soccer players and 13 marathon runners were studied. Each subject was tested in the sitting position and made to perform 50 consecutive right knee bends and stretches at maximum strength. This was done 3 times with an interval of 10 min between each series. The peak torque to body weight ratio and the fatigue rate were determined in each case. In all subjects, the peak torque to body weight ratio was higher for extensors than flexors. Over the 3 trials, the fatigue rate of extensors showed little change, while that of flexors had a tendency to increase. In each subject, knee extensors showed a high fatigue rate but a quick recovery, while knee flexors showed a low fatigue rate but a slow recovery. As the marathon runners had the smallest fatigue rates for both flexors and extensors, we concluded that marathon runners had more stamina than baseball players and soccer players.

To assess the effects of service dogs on health-related quality of life (HRQOL), we conducted a survey of 10 service dog owners using SF-36v2 (Medical Outcomes Study 36 Item Short-Form Health Survey Version 2.0) and compared it with a matched control group of people with physical disabilities who did not have service dogs but were eligible for one. The scores for mental health and role emotional of service dog owners were relatively high, and their mental component summary was higher than the general population norm. These results indicate that service dogs affect the mentality of their owners. The comparison with the control group indicated that service dogs alleviate the mental burden of daily activities, and subjectively improved the physical functioning of their owners. This study showed that service dogs have positive functional and mental effects on their disabled owners.