ABSTRACT
Objective：This study aimed to determine the difference in knee joint range of motion (ROM) and coefficient of variation (CV) during preoperative single-leg squatting in patients who developed ipsilateral lower limb anterior cruciate ligament (ACL) re-injury months after ACL reconstruction and in those who did not have the injury.Methods：Participants included 38 patients with non-contact ACL injuries. All patients underwent single-leg squatting the day before ACL reconstruction. Knee joint ROM and CV were assessed during single-leg squatting using a three-dimensional motion analysis system. We investigated the occurrence of ACL reinjury in the ipsilateral lower limb approximately 30 months after ACL reconstruction. Knee joint ROM and CV were then compared between the postoperative and non-injury groups.Results：The postoperative injury and non-injury groups included 9 and 29 patients, respectively. The knee internal/external rotation ROM and CV of knee varus/valgus ROM were greater in the postoperative injury group than in the postoperative non-injury group.Conclusion：During single-leg squatting before ACL reconstruction surgery, the knee internal/external rotation ROM and CV of knee varus/valgus ROM were suggested to be points of evaluation when considering ACL re-injury prevention.
ABSTRACT
In this study, we examined the relationship between physical function and muscle strain of hamstrings in junior high school soccer players. The subjects were 29 junior high school soccer players. The muscle strength of knee flexors and extensors relative to body weight and the hamstrings/quadriceps muscle strength ratio (H/Q ratio) were measured, and a tightness test, general joint looseness test and the New Physical Fitness Test of Japanese Ministry of Education and science were performed. We contacted the trainer to confirm occurrence of hamstrings strain, and we compared the above measurement and test results in subjects with and those without hamstring strain. Differences were analyzed by the unpaired t-test. There were significant differences between the two groups in muscle strength of knee extensors, H/Q ratio and tightness of hamstrings (p<0.05). The results suggest that increasing the H/Q ratio and stretching hamstrings are important for preventing hamstrings strain in junior high school soccer players.
ABSTRACT
<p><b>OBJECTIVE</b>Previous studies on the association between physical activity (PA) and neighborhood environments (NE) focused on either objectively measuring the NE or the residents' perception of NE. Here, we investigate which actual or perceived NE is associated with residents' PA in Japan.</p><p><b>METHODS</b>Two regions with an objectively assessed high and low residential density, land use mix-diversity, and street connectivity, respectively, were identified in one city. The subjects were selected using a stratified random sampling method by sex and age in each region. The NE of the subjects was objectively measured using the Geographic Information System (GIS), and the subjects' perception of the NE was assessed using a questionnaire. The daily total number of walking steps was measured with an accelerometer, and walking and cycling time were assessed by a questionnaire.</p><p><b>RESULTS</b>For the female subjects, the mean cycling time, subjectively assessed as a means of transport, was significantly longer in the group with a high GIS score for the number of land use types, while the score for total number of walking steps was significantly higher among those who were aware of places to walk to, and cycling time for transport was longer for those who perceived an accessibility to post offices, banks/credit unions, gymnasiums/fitness facilities, and amusement facilities in their neighborhood. For the male subjects, the score for walking time for leisure was longer for those who perceived aesthetics and an accessibility to parks, and the score for total walking steps was significantly higher for those who perceived an accessibility to bookstores or rental video stores in their neighborhood.</p><p><b>CONCLUSIONS</b>The results to this study demonstrate that daily PA was high among female subjects living in a NE with land use mix-diversity, and who had an awareness of places to walk to and the accessibility to facilities for daily necessities in their neighborhood. For male subjects, daily PA was high among those who perceived the aesthetics of and accessibility to facilities for pleasure in their neighborhood. Further research is needed to determine the association between PA and NE on the basis of sex differences.</p>