Comparison of Trunk Muscle Strength in Collegiate Wrestlers with Lumbar Intervertebral Disc Degeneration

Abstract

1402 We reported at the 50th ACSM annual meeting that collegiate wrestlers without radiological abnormalities (RA) showed a significant relationship between trunk extensor strength and the level of low back pain. The same tendency could not be observed in wrestlers with RA. However, the RA group showed a variety of abnormalities. PURPOSE: For further characterization of the RA group, we particularly focused on the lumbar intervertebral disc degeneration (DD). We examined whether wrestlers with DD have lower trunk extensor strength than those without DD. Also, we confirmed the relationship between trunk extensor strength and the disability level of low back pain in wrestlers with DD. METHODS: The subjects were 41 male collegiate wrestlers. To focus on DD, we excluded the wrestlers who had RA other than DD. Based on the MR imaging, the three intervertebral lumbar discs from L3 to S1 were assessed. We classified the 41 wrestlers into two groups: the DD and the non-DD groups. Isokinetic trunk extensor strength was measured at three angular velocities (60, 90, 120°/sec). The indicators of trunk extensor strength were determined as peak torque, average torque, average power and work. All the trunk extensor strength parameters were divided by the subject's body weight. The functional disability level of low back pain was estimated by using a questionnaire developed by Osaka City University (the OCU test). Scores on the OCU test increased as the level of pain increased. Analyses were conducted using the unpaired t-test and Spearman's rank test. Statistical significance was positive at the 5% level. RESULTS: Without considering the level of low back pain, there were 12 wrestlers with low back pain (48%) in the DD group (N = 25) and 4 (25%) in the non-DD group (N = 16). The DD group showed a statistically significant low trunk extensor strength in most of the parameters compared with the non-DD group (peak torque at 90°/sec; P<0.01, 120°/sec; P<0.01, average torque at 90°/sec; P<0.01, 120°/sec; P<0.01, work at 60°/sec; P<0.05, 90°/sec; P<0.05, 120°/sec; P<0.01 and average power at 120°/sec; P<0.05). Body weight in the DD group was significantly heavy (P<0.05). On the contrary, trunk extensor strength did not significantly correlate with the disability level of low back pain in the DD group. CONCLUSION: We concluded that collegiate wrestlers with lumbar intervertebral disc degeneration show greater incidence of both low back pain and low trunk extensor strength. One of the reasons for the absence of significant correlation between disability level and extensor strength might be the overall low trunk muscle strength in the DD group.