Reviewed by Austin Mowrey PT, DPT
Hamstring injuries are common in many sports that require repetitive acceleration and deceleration, including football, soccer, and basketball. There is also a correlation between hamstring mobility and pelvic, knee and low back pain. The aim of this study was to compare foam rolling and proprioceptive neuromuscular facilitation (PNF) to address hamstring mobility deficits.
Methods and Interventions:
This study consisted of 80 subjects over 18 years old with no history of hypermobility, hamstring injuries in the past 6 months, a diagnosed orthopedic problems or surgery in the lower limb, back pain or spine surgery, and systemic and neurological disorders. The sample consisted of 53 men and 27 women with an average age of 22.82 years. Subjects were randomly assigned to receive PNF treatment or foam rolling treatment. Hamstring mobility was assessed using a modified sit-and-reach test before interventions, during interventions and 2 minutes after interventions. The subject’s discomfort was also measured using the BORG RPE scale at the end of the intervention.
The PNF group consisted of 29 men and 11 women with an average age of 22.48. The PNF stretching protocol was performed with each participant in a long sitting position on a plinth. The participant was asked to perform a maximal isometric hamstring muscle contraction for 5 seconds followed by 5 seconds if relaxation and 20 seconds of stretching (30 seconds total). Each participant underwent four repetitions of the PNF stretching in which hamstring length was recorded at baseline, at the end of first repetition, and at the end of the protocol.
The foam roll group consisted of 24 men and 16 women with an average age of 22.50. For the foam rolling protocol, each participant assumed the long sitting position on a firm and even surface by placing their arms backward and transferring their weight to their palms. The foam roller was placed bilaterally under their hamstrings and slowly moved back forth from the ischial tuberosity and the popliteal fossa for two minutes. Hamstring length was recorded at baseline, 30 seconds from the start of the intervention and at the end of the protocol.
Baseline measurements of hamstring flexibility demonstrated no significant differences between each group, but both groups had statistically significant increase in hamstring flexibility during the interventions and after the intervention. The PNF group demonstrated a 56% total gain of hamstring mobility after the first bout of PNF stretching and the rest during the last three bouts. The foam roll group demonstrated 47% of the total gain after 30 seconds of foam rolling and the rest during the last 90 seconds. When comparing PNF stretching vs foam rolling for hamstring mobility, PNF stretching demonstrated statistically significant results during and after the interventions. There were no statistically significant results when comparing the participants’ perceived exertion between groups or with increased effort and flexibility gained.
The PNF group and foam rolling both experienced statistically significant increase in flexibility in their hamstrings during and after both interventions. When comparing the two groups, the PNF group had significant increase in hamstring flexibility compared to the foam rolling group, but both groups had similar sensation of perceived exertion.
Take Home Message:
It is important for clinicians to consider patients’ needs, body size, demographics and goals when deciding on the appropriate intervention. This study concludes that PNF stretching and foam rolling are both effective to improve hamstring flexibility, but PNF is more effective for the population studied. Further research should be performed to assess the duration of the physiological changes noted in this study.
Pérez-Bellmunt A, Casasayas-Cos O, Ragazzi P, Rodríguez-Sanz J, Hidalgo-García C, Canet-Vintró M, Caballero-Martínez I, Pacheco L, López-de-Celis C. Foam Rolling vs. Proprioceptive Neuromuscular Facilitation Stretching in the Hamstring Flexibility of Amateur Athletes: Control Trials. International Journal of Environmental Research and Public Health. 2023; 20(2):1439. https://doi.org/10.3390/ijerph20021439