Superficial heat administration and foam rolling increase hamstring flexibility acutely; with amplifying effects

To compare the objective and subjective efficacy of three treatments on acute hip-flexion range of motion (ROM).

Assessor-blind, randomized within-subject cross-over.

University athletic training clinic.

Twenty-two female collegiate lacrosse and soccer athletes.

The passive straight-leg-raise (PSLR) was used to measure acute hip-flexion ROM pre- and post foam rolling (FR), superficial heating (SH), combination (SH + FR) and control treatments. A seven-point Likert scale statement measured the perceived effectiveness of each treatment.

Superficial heat (+10.4%, ES = 0.78), FR (+7.26%, ES = 0.52), and SH + FR treatment (+12.9%, ES = 1.26) improved hip ROM when compared to the control (+2.4%, ES = 0.24) (all p < 0.001). The SH + FR treatment resulted in a greater improvement in hip ROM compared to FR (p = 0.001, ES = 0.95), whereas no significant difference was observed between the SH and FR (p = 0.083, ES = 0.68) or SH and SH + FR treatment (p = 0.270, ES = 0.43). SH + FR was perceived as more effective than FR (p = 0.033, ES = 1.21), but not SH (p = 0.193, ES = 0.63). However, only a moderately positive correlation (r = 0.508) between objective and subjective measures of hamstring flexibility was found.

All treatments significantly improve hamstring flexibility with SH + FR being the most effective. Rehabilitation professionals should practice caution when relying on athlete perception and should prescribe treatments on an individual basis.