Trunk Alignment of Elite Male Swimmers with a History of Low Back Pain during a Streamlined Position

Abstract

Objectives: By contrasting elite male swimmers without a history of low back pain, the aim of this study is to explain the characteristics of trunk alignment during a streamlined position in elite male swimmers with a history of low back pain.

Methods: A total of 24 male elite swimmers were divided into two groups: one with a history of low back pain and the other without (LP: 9 swimmers with low back pain, NP: 15 swimmers without low back pain). The trunk alignments during a stance and a streamlined position on the ground were assessed to investigate the differences in the flexibilities of the shoulder girdle, ribcage, and hip. To compare the outcomes of the two groups, a T-test was performed.

Results: During the streamlined position, there was a significant difference in the pelvis, trunk, and lumbar angle, while there were no significant differences during the stance position. In comparison with NP, the lumbar lordosis angle, pelvic anterior tilting angle, upper trunk posterior tilting angle, and upper trunk extension angle were all greater in LP. Moreover, the flexibility of the lower ribcage was also found to be slightly lower in LP during the streamlined position, with no differences in the stance position.

Conclusions: We clarified that swimmers with a history of low back pain were unable to control their trunk alignment during a streamlined position. In LP, the lack of flexibility in the lower ribcage was shown, implying that it may be a major contributor to excessive lumbar lordosis in a streamlined position.