Study design: Experimental, controlled trial. Objectives: To identify the relationship between the muscular and articular factors in the progression of contractures after spinal cord injury (SCI). Setting: Hiroshima University, Hiroshima, Japan. Methods: In total, 48 female Wistar rats were used. The 24 experimental rats that underwent a spinal cord transection and the other 24 control rats that underwent a sham-operation were assessed at 2, 4, 8, 12, 16, or 24 weeks postsurgery. Knee joint motion was measured for flexion and extension. Myotomy of the transarticular muscles was then performed and range of motion was measured again. The degree of contractures was assessed by goniometry measuring the femorotibial angle before and after the myotomies. Results: The spinal cord-injured rats demonstrated flaccid paralysis during the first few days postsurgery and thereafter spastic paralysis. Intra-and inter-rater reliabilities for all measurements were 40.814. Knee flexion contractures developed in the all experimental rats, and progressed for the first 12 weeks and plateaued thereafter. Both the muscular (4875%) and articular (5275%) factors contributed almost equally to the overall progression of the contracture. Conclusion: The present findings may shed light on the underlying pathophysiology of contractures and should help guide research towards finding the elucidation of contracture development after SCI.

following central nervous system injuries remain a prevalent and significant complication, but no reports are available on evidence of contracture formation over time. The objective of this study was to determine the rate of contracture progression and the direction of loss in joint movement following spinal cord injuries (SCI). Forty-eight female Wistar rats were used. Twenty-four experimental rats underwent a spinal cord transection at the level of T8 and 24 control rats underwent a sham-operation. The animals were studied at each of 5 time points: 2, 4, 8, 12, 16, and 24 weeks after surgical intervention. The degree of contractures was assessed by measuring the femorotibial angle on both hindlimbs with the use of a goniometer. Knee joint motion was measured for flexion and extension direction. Knee flexion contractures developed in all experimental rats. The restriction in motion progressed during the first 12 weeks and plateaued thereafter. The contractures were produced almost exclusively by a loss in the extension range of motion. This study defined the time course that contracture progression was more rapid in the early stage after SCI and stabilized in the later stage of injury. Contractures following SCI occurred in flexion at the knees and resulted from a loss of extension. These findings should help guide timely treatment and provide a better understanding of contracture development. ----contracture; range of motion, articular; spinal cord injuries; rats

The objective of this study was to assess the effect of comprehensive exercise program widely accepted as a community-based physical intervention for the prevention of falling in the elderly persons on their controlling standing balance. Twenty-six community-dwelling elderly persons (13 males and females; 69.8 ± 2.8 years old) participated in this study. Daily exercise was comprised of walking for more than 30 min, stretching, muscle strengthening and balance exercise without exercise equipments. The intervention was continued for three months. Indicators of standing balance related to static balance, dynamic balance and postural response were measured before and after the intervention. As an effect of the intervention on static balance, the sway of center of pressure (COP) in the static stance significantly increased. In the dynamic balance, significant improvements were observed in one leg standing time, the 10-m gait time, functional reach. Additionally, the maximal movable length of COP which subjects can move voluntarily to right and left significantly increased. In the postural response, the integrated electromyography (IEMG) induced by postural response for sudden postural perturbation significantly decreased in the lower leg muscles. Since less muscular activities were sufficient to maintain posture, it was suggested that postural response was elicited more efficiently following the intervention. This study suggested that the comprehensive exercise program, which has been widely introduced as community-based interventions for the prevention of falling, have extensive effects on the control of standing balance covering static balance, dynamic balance and postural response in the elderly persons.

Reflecting the rapidly aging population, community-based interventions in the form of physical exercise have been introduced to promote the health of elderly persons. Many investigation studies have focused on muscle strength in the lower leg as a potent indicator of the effect of physical exercises. The objective of this study was to assess the effect of long-term daily exercises on neural command in lower leg muscle activations. Twenty-six community-based elderly persons (13 men and 13 women; 69.8 ± 0.5 years old) participated in this study. Daily exercise was comprised of walking for more than 30 min, stretching, muscle strengthening and balance exercise, and was continued for three months. Muscle strength and surface electromyography of the tibia anterior, rectus femoris, and biceps femoris were measured in maximum isometric voluntary contraction both before and after the intervention. The mean frequency of the firing of motor units was calculated based on fast Fourier transformation of the electromyography. As the results of the intervention, muscle strength increased significantly only in biceps femoris, whereas the mean frequency of motor units decreased significantly in every muscle, indicating that motor unit firing in lower frequency efficiently induces the same or greater strength compared with before the intervention. Thus, synchronization of motor units compensates for the lower frequency of motor unit firing to maintain muscular strength. In conclusion, long-term physical exercises in the elderly can modulate the neural adjustment of lower leg muscles to promote efficient output of muscle strength. electromyography; elderly person; physical exercise

No abstract