This study, conducted by Physiotherapy student Andrew Mooney, examined the flexibility of four major muscle groups associated with movement of the hip, with particular attention to imbalances between the left and right sides or between the dominant and non-dominant sides. A total of 33 male subjects were included in the study. Runners with lower back pain were recruited first. The first, relative flexibility, was related to the range of movement of the joint before postural compensations occurred, and the second was a measure of the maximal functional length of the muscle. Relative flexibility and functional length were measured for each muscle group on both the left and right sides of the body.
Positive numbers indicate above the horizontal, negative numbers below the horizontal.
A study in the flexibility of the hip muscles in runners with low back pain . Honours Thesis, Department of Physiotherapy, University of Queensland. The measurements are very variable, but the plots below show that the back pain group tends to have shorter and less flexible muscles than the other two groups. The dominant hamstring seems to be more flexible than the nondominant, although surprisingly this is mainly so for the sedentary group. Both the average hamstring flexibility, and the difference between the dominant and nondominant hamstring flexibility, increase with the weight of the subject.