Thoracolumbar Fascia and Lumbar Muscle Stiffness in Athletes with A History of Hamstring Injury

The purpose of this study was to examine the differences in thoracolumbar fascia (TLF) and lumbar muscle modulus in individuals with and without hamstring injury using shear wave elastography (SWE). Thirteen male soccer players without a previous hamstring injury and eleven players with a history of hamstring injury performed passive and active (submaximal) knee flexion efforts from 0 degrees, 45 degrees and 90 degrees angle of knee flexion as well as an active prone trunk extension test. The elastic modulus of the TLF, the erector spinae (ES) and the multifidus (MF) was measured using ultrasound SWE simultaneously with the surface electromyography (EMG) signal of the ES and MF. The TLF SWE modulus was significantly (p < 0.05) higher in the injured group (range: 29.86 +/- 8.58 to 66.57 +/- 11.71 kPa) than in the uninjured group (range: 17.47 +/- 9.37 to 47.03 +/- 16.04 kPa). The ES and MF modulus ranged from 14.97 +/- 4.10 to 66.57 +/- 11.71 kPa in the injured group and it was significantly (p < .05) greater compared to the uninjured group (range: 11.65 +/- 5.99 to 40.49 +/- 12.35 kPa). TLF modulus was greater than ES and MF modulus (p < 0.05). Active modulus was greater during the prone trunk extension test compared to the knee flexion tests and it was greater in the knee flexonly (p < 0.05). SWE modulus of the TLF and ES and MF was from sustaining a new injury.