Some personal trainers and manual therapists emphasize that having your body in the a “symmetrical” body can help you alleviate back pain (and other types of musculoskeletal pain). While this premise may be apply to certain individuals and populations, a recent South African study that was published in Journal of Science and Medicine in Sport found that cricket fast bowlers with abdominal symmetry have higher incidences of low back pain than those who have abdominal muscle asymmetry. (1)
Twenty-five teenage cricket fast bowlers participated in the study in which sixteen of them have low back pain and nine don’t. Among those without low back pain, the researchers found that the thickness of their external obliques, internal obliques, and transversus abdominis on the non-dominant side was greater than those of the dominant side. But those with pain, both sides of the muscles were more symmetrical than the players without pain.
The researchers hypothesized that the asymmetry on the non-dominant side “would appear to be protective rather than provocative” for low back pain. Thus, it is possible that the muscle hypertrophy is an adaptation to pain. When cricket players are compared with healthy non-athletes, the latter have more trunk symmetry with minor variability among the individuals.
Rather than only focusing on making the body look more “equal,” therapists and trainers should examine other factors that could increase in the risk of pain and injury in their athletes. For example, among cricket fast bowlers, contralateral lumbar flexion and ipsilateral rotation of the trunk —combined with the fast pitch around the time the ball is released — show a strong risk for back injury (2). The relationship among injury risk, biomechanics, and asymmetry have not yet been established, which require further research.
1. Gray J, Aginsky KD, Derman W, Vaughan CL, Hodges PW. Symmetry, not asymmetry, of abdominal muscle morphology is associated with low back pain in cricket fast bowlers. Journal of Science and Medicine in Sport. 2015 Apr 23. pii: S1440-2440(15)00091-2. doi: 10.1016/j.jsams.2015.04.009.
2. Ranson CA, Burnett AF, King M, Patel N, O’Sullivan PB. The relationship between bowling action classification and three-dimensional lower trunk motion in fast bowlers in cricket. Journal of Sports Sciences. 2008 Feb 1;26(3):267-76.