This prospective study was designed to evaluate whether static stretching can prevent training-related injuries in Japan Ground Self-Defense Force military recruits. A total of 901 recruits between 1996 and 1998 were divided into two groups. Of which, 518 recruits were assigned to the stretching group and practiced static stretching before and after each physical training session. The control subjects (383 recruits in the nonstretching group) did not stretch statically prior to exercise. The static stretching consisted of 18 exercises. We collected injury data from medical records and assessed the incidence and the location of injury. The total injury rate was almost the same between two groups; however, the incidences of muscle/tendon injury and low back pain were significantly lower in the stretching group (p < 0.05). Static stretching decreased the incidence of muscle-related injuries but did not prevent bone or joint injuries.

Forty-three trigger thumbs and fingers in 33 children (15 boys and 18 girls, average age 2 years and 4 months) were treated using a polyethylene splint. Affected digits included 40 thumbs, one index finger, and two middle fingers. The IP joint was stabilized in maximum extension via a strap on the dorsal side. The splint was applied only at night and during day-time naps. Twenty-four digits recovered completely in an average of 10 months, seven digits improved, and two digits required surgery. Eight patients (10 digits) dropped out of treatment. Splint therapy is effective in treating trigger thumbs and fingers in children.

Distraction osteogenesis is a form of in vivo tissue engineering in which the gradual separation of cut bone edges results in the generation of new bone. In this study, the temporal and spatial expression of bone morphogenetic proteins (BMPs) 2, 4, and 7 was examined in a rabbit model of mandibular distraction osteogenesis. Fourteen skeletally mature male rabbits were studied. After osteotomy, a distractor was applied to one side of the mandible. After 1 week of latency, distraction was initiated at 0.25 mm every 12 hours for 3 weeks (distraction period), followed by a 3-week consolidation period. Two animals were killed each week after surgery. The generate bone was analyzed for the expression of BMP-2, -4, and -7 by using standard bone histological and immunohistochemical techniques. BMP-2 and -4 were highly expressed in osteoblastic cells during the distraction period and in chondrocytes during the consolidation period. BMP-7 demonstrated relatively minor expression in osteoblastic cells during the distraction period. All BMPs were strongly expressed in vascularized connective tissue during the distraction period. These data indicate that BMPs participate in the translation of mechanical stimuli into a biological response during mandibular distraction osteogenesis.