The relatively low strength of trunk extensors may be one of the factors related to nonspecific chronic low back pain in collegiate wrestlers.

This study evaluated the sport-specific characteristics of the cross-sectional areas (CSAs) of trunk muscles and trunk muscle strength in wrestlers and judokas. We also examined whether their trunk muscles and muscle strength depended on athletic performance levels in each sport. The subjects comprised 14 male collegiate wrestlers and 14 judokas. Magnetic resonance imaging was used to assess the trunk muscle CSAs at the L3-4 level parallel to the lumbar disc space. A Biodex System3 was used to measure isokinetic trunk flexor and extensor muscle strength of peak torque, work, average torque, and average power. The absolute and relative CSAs of the trunk muscles in the wrestlers and judokas were significantly different (rectus abdominis: wrestling > judo, P < 0.05; obliques: wrestling < judo, P < 0.05; quadratus lumborum: wrestling < judo, P < 0.01). We confirmed that the absolute and relative trunk extensor and flexor strength of peak torque, work, and average torque were significantly higher in the collegiate wrestlers than in judokas. On athletic performance, the tendency of the CSAs and muscular strength of trunk muscles was not consistent with athletic performance levels in each sport. Our findings indicated that the sport-specific characteristics of the CSAs of the trunk muscles and trunk muscle strength obviously differed between the 2 similar sports. Athletes should practice the sport-specific training of trunk muscles and develop sport specificity in their sports. Particularly, wrestlers have to train in trunk flexion and extension motions, and judokas need to strengthen trunk rotation and lateral flexion motions. This information will be available for athletes as well as strength and technical training coaches in wrestling, judo, and the other sports.

Grip style may be associated with ACL injury occurrence in judo. In addition, direct contact due to the opponent's attack may be a common mechanism for ACL injuries in judo.

STUDY DESIGN: Cross-sectional study of a specific population. OBJECTIVES:To investigate the prevalence and coprevalence of nonspecific low back pain (nsLBP) and lumbar radiological abnormalities (LRA) in judo athletes.BACKGROUND: nsLBP and LRA occur frequently in judo athletes. High body mass has been reported to be associated with both nsLBP and LRA. METHODS AND MEASURES:The subjects comprised 82 male judo athletes (mean SD age, 20.1 0.9 years) from 3 weight categories: lightweight (n = 29), middleweight (n = 31), and heavyweight (n = 22). The presence of nsLBP was evaluated using a questionnaire. LRA were examined using plain-film radiographs and magnetic resonance imaging. The prevalence of nsLBP and LRA were compared among weight categories. RESULTS:The prevalence of nsLBP in the lightweight, middleweight, and heavyweight categories was 34.5%, 32.3%, and 40.9%, respectively. For LRA, prevalence for the 3 weight categories was 65.5%, 90.3%, and 90.9%, respectively (middleweight and heavyweight greater prevalence than lightweight [P .05]). The prevalence of LRA in athletes with nsLBP in each category was 50.0%, 100%, and 88.9%, respectively (middleweight greater prevalence than lightweight [P .05]). The prevalence of LRA in athletes without nsLBP in each category was 73.7%, 85.7%, and 92.3%, respectively. CONCLUSIONS:The prevalence of LRA was approximately 90% in the middleweight and heavyweight categories, which was greater than for the lightweight category. There was a large coprevalence of nsLBP and LRA. However, many judo athletes without nsLBP had LRA. The presence of LRA may not have a direct association with nsLBP.

BackgroundLumbar intervertebral disc degeneration (LDD) frequently occurs in athletes. Associations between LDD and trunk muscles still remain unclear.PurposeThis study examined whether there is an association between the prevalence of LDD and the symmetry and size of the cross-sectional areas (CSAs) of the trunk muscles in combat sports athletes.MethodsParticipants in this study were 151 collegiate male combat sports athletes. A total of 755 lumbar intervertebral discs from L1–2 to L5–S1 in 151 athletes were assessed using magnetic resonance imaging (MRI) and a comprehensive grading system of LDD (grades I–V). All 151 athletes were divided into 2 groups: LDD and non-LDD. CSAs of trunk muscles at the L3–4 disc level were measured using MRI.ResultsSixty-nine athletes had LDD at 1 or more disc levels (45.7 %). The LDD grade for the lower 2 disc levels was significantly higher than that for the other disc levels (p < 0.001). The CSAs of the left and right sides in trunk muscles were significantly asymmetrical, independent of the LDD which was prevalent in the disc levels (obliques: p = 0.040; quadratus lumborum: p < 0.001). The relative CSAs of trunk muscles to their body weight in the LDD group were significantly smaller than those in the non-LDD group (rectus abdominis: p = 0.011; obliques: p = 0.024; quadratus lumborum: p = 0.006; lumbar erector spinae plus multifidus: p = 0.001).ConclusionThis study suggests that the prevalence of LDD is associated with asymmetrical and relatively smaller CSAs of trunk muscles in combat sports athletes.