Knee extensor and flexor muscles are often injured due to an imbalance between these groups, which may lead to a deficit in muscle performance. Thermal resources, such as cryotherapy, and stretching techniques, such as the "hold-relax" of proprioceptive neuromuscular facilitation (PNF), influence flexibility and muscle strength and may reduce the chances of muscle tendon injuries. The aim of the study was to verify the effects of cryotherapy and of the PNF hold-relax technique on muscle strength at the flexor and extensor muscles of the knee. The sample was made up by 18 sedentary women aged 18 to 24 years old, who were divided into two groups: one was submitted to cryotherapy and the other, to the hold-relax technique. Before and after one session of either technique subjects were submitted to isokinetic evaluation. The hold-relax technique brought an increase in strength of both muscle groups in both limbs, reaching significance level at the right limb flexors (p=0.04). Cryotherapy reduced the strength of the extensors and had the opposite effect at the flexors, generating a significant increase at right limb flexors (p=0.035). When comparing both techniques, the hold-relax technique generated higher peak torque values, mainly at the extensor muscle of the left limb (p=0.042). Hence the PNF hold-relax technique was able to generate higher knee muscle peak torque than cryotherapy.
Cryotherapy; Evaluation of results of therapeutic interventions; Knee; Muscle strength
