The purpose of this study is to identify the risk factors which affect the consecutive onset of throwing shoulder injury of a collegiate baseball team, and to calculate regression formula which could predict the future onset.Prospective study. The subjects are 69 asymptomatic collegiate baseball players. We executed medical checkups and investigated who got throwing shoulder injury during this year. We did logistic regression analysis with the medical checkup findings and the data of the onset and found out the factors which significantly affected the onset. We also calculated Odds ratio of these factors and regression formula which predict the probability of the onset of throwing shoulder injury and evaluated the validity of regression model.52%(36/69 cases) of the players suffered throwing shoulder injury during this year. Among the medical checkup findings of asymptomatic phase, pitcher and catcher, past history of throwing shoulder injury, abnormality of scapula-humeral rhythm, heel-buttock distance were thought to be the risk factors which were near-related to the onset of throwing shoulder injury. We calculated regression formula using the medical checkup findings of asymptomatic phase and we could predict the onset of throwing shoulder injury with 82.5% accuracy.In order to prevent this injury, the method used in this study could be useful for field players to predict the onset of throwing shoulder injury.

The purpose of this study was to investigate the effects of running training on bone formation in rats in relation to the age training started. The first experimental period was set from 6 to 12 weeks (wks) old and the second from 12 to 19 wks old. Sixty-four Wistar strain 6-wk-old male rats were initially divided into a non-exercise (N) and an exercise (E) group. At 12 wks old, each group was subdivided into two groups, providing four groups: non-exercise·non-exercise (NN), non-exercise·exercise (NE), exercise·non-exercise (EN) and exercise·exercise (EE) . Exercise consisted of treadmill running at a speed of 30 m/min, 60 mm day, 5 days wk. The animals were sacrificed before the experiment (6 wks old), post-first experiment (12wks old) and postexperiment (19 wks old), the bilateral tibiae were removed and their lengths, bone mineral content (BMC), bone mineral density (BMD) and bone histomorphometric parameters were measured. The tibial length was significantly shorter in 12-wk-old E than N rats and in 19-wk-old EE than NN. At 19 wks old, the total tibial BMD values were significantly higher in EE than NN, and the BMD values of the proximal and distal tibiae, where the cancellous bone was the main component, had increased markedly, whereas no differences between the diaphyseal BMD of each group were noted. Bone histomorphometry at 12 wks old, considered the immature period, showed that the osteoid surfaces and labeled surfaces tended to be increased by running training, but the bone volume was unchanged. In contrast, at 19 wks old, considered the early mature period, the osteoid surfaces showed a tendency to decrease and labeled surfaces to increase and consequently the bone volume increased albeit not significantly. These results suggest that: 1) running training started in immature rats represses longitudinal tibial growth, 2) the cancellous bone is more sensitive then the cortical bone to this type of training and 3) training of early mature rats increases bone volume by increasing the efficiency of osteoid calcification.

To investigate the influence of long-distance running on bone metabolism, we measured bone metabolism markers in eight healthy young men before and 4 months after the start of training program of 10 km running. Measurements were then taken the day before a marathon race, immediately after, and 1 day, 2 days and 5 days after.
As a result of exercise, the levels of serum osteocalcin (OC), a bone formation marker, and urinary deoxypyridinolin (D-Pyr), a bone resorption marker, decreased significantly. After the marathon race, the OC level decreased further corresponding to an increase of hydrocortisone right after the race. However, from the day following the race, the OC level showed a slight increase. D-Pyr showed an increasing tendency immediately after the race, and the levels of OC and D-Pyr increased significantly 5 days after the race.
Bone formation and resorption decreased as a result of light, low-frequency endurance exercise. However, both of them increased after intense physical stress. From this result, it is suggested that the intensity and frequency of exercise affect bone metabolism differently, even though the type of exercise load is similar.

Delayed Onset Muscle Soreness (DOMS) is characterized by a sensation of discomfort that usually develops 24-48 hours after unaccustomed exercise, with muscle swelling and stiffness that usually results in a reduced range of movement. Muscle weakness is often seen. It may be surmised that DOMS is a problem that affects all athletes.
We examined six male subjects to determine the effect of acupuncture stimulation on DOMS, which was induced experimentally in both legs using a heel raising exercise. Acupuncture stimulation has long been used in the treatment of pain, but there is insufficient proof of its efficacy. A problem acupuncture research has had to face is the concept of a control group. To deal with this, we used non-invasive acupuncture stimulation, which would allow the simulation of the acupuncture procedure without penetrating the skin. The leg that would receive actual acupuncture stimulation and the leg that would receive non-invasive stimulation after the induction of DOMS were determined by randomization.
The muscle stiffness, ankle range of movement, maximal voluntary contraction, one-legged vertical jump, muscle tenderness, pain on muscle stretching, pain on muscle contraction, ankle mobility and subjective muscle strain were measured as indices of stimulation efficacy. Pain on muscle stretching was significantly less (p<0.05) at 48 hours after exercise for the side stimulated by acupuncture as compared with the side stimulated non-invasively. The other indices did not differ significantly between the side stimulated using acupuncture stimulation and the side stimulated non invasively. These results suggest that the early relief of DOMS can be achieved by acupuncture stimulation.

[Objective] The purpose of this study was to determine whether icing treatment has an effect on muscle reaction time and functional performance of a sprained ankle. [Methods] Subjects were six persons (healthy group) and six persons who had an acute ankle sprain (patient group) . Anterior talar translation and talar tilt of the six patient group were evaluated by the stress X-ray measure. Ice treatment was applied for 20 minutes. [Results] The following points were clarified : 1) Reaction times of peroneus longus (PL) and peroneus brevis (PB) for the sprained ankle group (SA) were significantly longer than those for the non-sprained ankle group (NA) (p<0.05) . Length of time of standing on one leg with closed eyes for SA was significantly shorter than for NA (p<0.05) . 2) After icing treatment, reaction time of PL for SA tended to be shorter. Furthermore, PB significantly decreased after icing treatment (p<0.05) . Side-steps for SA were significantly increased after icing treatment (p<0.05) . 3) Reaction times of PL and PB for NA significantly increased after icing treatment (p<0.05) . Standing on one leg with closed eyes for NA significantly decreased after icing treatment (p<0.05) . [Conclusion] It was shown that icing treatment of a sprained ankle leads to a shorter muscle reaction time and an increase in the number of side-steps. Therefore, it was concluded that icing treatment of a sprained ankle might be able to improve incapacitated neuromuscular function and functional performance by acute trauma.

The present study was designed to examine the positive impact of collagen and glucosamine hydrate supplementation on joint markers, matrix metalloproteinase-3 (MMP-3), tissue inhibitor of metalloproteinases-1 (TIMP-1) and keratane sulfate (KS) . Thirteen healthy fun-runners supplemented collagen and glucosamine hydrate for 30 days. Blood samples were collected on days 0, 15 and 30. The test-drink supplement, however, significantly decreased MMP-3 and KS on days 15 and 30. These results suggest that the supplementation of collagen and glucosamine hydrate may prevent injury and inflammation of joint cartilages and be useful for joint conditions.

The purpose of this study was to evaluate the change of the hardness of the gastrocnemius muscle (GM) and the Achilles tendon (AT) using Real-time Tissue Elastography (RTE) before and after acute exercise. Nine healthy young male without any exercising custom performed a total of 100 reps. of one-leg heel-rise exercise and the hardness of the gastrocnemius muscle and the Achilles tendon before and after the exercise was examined in comparison. The strain ratio (SR) was even measured in comparison to a reference material. The result indicated that the SR of the GM significantly increased immediately, 15min, 30min and 24h after the exercise, whereas the SR of the AT significantly increased just immediately and 15min after the exercise. In summary, the hardness of GM and AT increased after exercise. These findings suggest that RTE is a useful technique for assessing specific hardness of muscles and tendon, More RTE measurements of various parts of the body and the examination of the relationship between injury and RTE are required for the conditioning of muscles and tendons.

[Objective] The purpose of this study is to examine the relationships between shoulder's function and damage for handball players. Subjects were nine female handball players with dominant shoulder pain.[Methods] Clinical diagnosis was done from the medical doctor's opinion and MRI. Then, the shoulder joint movement was measured with X rays.[Results] Most of them had admitted a lot the impingement syndrome and the subacromial bursitis. The trunk rotation angle at zero-positions was significantly larger in the symptomatic shoulder (dominant shoulder) than in the asymptomatic shoulder (nondominant shoulder). That is, it was obvious that the damage of the shoulder changed tilting angle of scapula medially.[Conclusion] It is reported that the damage of the shoulder causes abnormality to the “scapulohumeral rhythm” by the previous research. But, these results, suggested to need to understand not only “scapulohumeral rhythm” but also movement to the position of the scapula, when the shoulder joint function was observed for the handball player mainly composed of throwing motion.

The aim of this study is to examine the potential of the two-dimensional posture evaluation method as a screening tool for detecting the high-risk population for anterior cruciate ligament injury.Eleven healthy adults participated in this study. They jumped from a 31 cm-high box and landed on their dominant leg. Three-dimensional knee flexion/extension, knee valgus/varus and hip adduction/abduction angle during single-legged landing were calculated. At the same time, the Frontal-plane Knee Displacement index (FKD)-the knee joint position relative to the line between the hip and ankle joint-was measured.FKD reflects the time variation of three-dimensional knee valgus and hip adduction angle very well.Our results suggest that FKD has potential as a screening tool particularly for movement occurring primarily in the frontal-plane.

PURPOSE : To determine the patterns of electromyographic (EMG) responses and torques of upper extremity muscles in overhead throwers during maximal, eccentric muscle action for shoulder flexion (Flex_Ecc), abduction (Abd_Ecc) and diagonal activities (Dia_Ecc) with full glenohumeral internal rotation, at 60, 120, and 180°/s on the dynamometer.METHODS : Seven asymptomatic subjects (7 men, 4 women) who participate in overhead sports at least three days a week volunteered to participate in this study. Subjects were randomly performed with the test procedure which consisted of at least 5 grade maximal-effort repetitions on the three different testing conditions, at 60, 120, and 180°/s on the dynamometer, while we assessed muscle activation of the anterior deltoid (AD), middle deltoid (MD), posterior deltoid (PD), upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and biceps brachii (BB) muscles by surface electromyography. EMG data was expressed as a percentage of maximum voluntary isometric contraction (%MVIC) that was obtained from the highest root mean square (RMS, 50 ms) of each muscle and was normalized and averaged.RESULT : AD muscle elicited lower muscle activity during Dia_Ecc than Flex_Ecc and Abd_Ecc (P＜0.05) while the MD, PD, UT, MT, and LT muscles elicited overall greater muscle activities during Dia_Ecc. MD and MT muscle activities were significantly greater for the faster speed than for the slower speed as 60°/s during Abd_Ecc (P＜0.05). Peak torque generated greater muscle strength for Dia_Ecc than Flex_Ecc and Abd_Ecc, and it was significantly greater for the faster speed than slower speed during Dia_Ecc (P＜0.05).CONCLUSION : Posterior upper extremity muscle activities and peak torque values were found to be dependent on eccentric muscle action for diagonal shoulder activity at the faster speed. This study provided evidence that isokinetic eccentric muscle strength testing of the posterior upper extremity muscle was effective to develop of a proper program for overhead sports athletes require forceful stability during deceleration phase.