Effect of heat and cold on tendon flexibility and force to flex the human knee

Abstract

BackgroundIt is commonly believed in medicine that using heat will increase the distensability and flexibility of soft tissue. If true, increased flexibility would be a positive factor to reduce injuries in sports. However, cold should have the opposite effect and is often used to treat sports injuries. This study was accomplished to quantify the effect of heat and cold on the force needed to flex the knee and laxness of the anterior and posterior cruciate ligaments.Material/MethodsThe present study examined 20 male and female subjects to determine if heat would increase extensibility of the anterior and posterior cruciate ligaments of the knee and reduce the force needed to flex the knee. Cold exposure was examined to see if it would have the opposite effect. There were 4 experiments in the series: The first was a room temperature series; the second was a series where cold was applied with an ice pack for 20 minutes; in the third, hydrocollator heat packs were applied for 20 minutes; and in the fourth, ThermaCare heat wraps were applied for 4 hours on the quadriceps and knee. Tendon extensibility was measured with a KT2000. The force for flexing the knee was measured by passive movement being applied (CPM) to the knee through 30° and the force required to move the leg was measured.ResultsThe results show that the anterior and posterior cruciate ligament flexibility increased and the force needed to move the knee decreased with heat by about 25% compared to cold application.ConclusionsHeat is beneficial in increasing muscle and ligament flexibility and may help reduce athletic injuries, but cold treatment may have the opposite effect.

Efeito agudo da crioterapia e diatermia na flexibilidade e força muscular de isquiotibiais

“…Estes estudos relatados anteriormente, apesar de terem submetidos os sujeitos a um programa de treinamento, diferentemente do nosso estudo, corroboram com os nossos achados no quesito força muscular associado ao calor profundo, em que verificamos que a diatermia por ondas curtas não altera de forma aguda a força muscular de isquiotibiais em mulheres jovens. Contrariando os estudos anteriores, Petrofsky et al 26 abordaram 20 sujeitos com calor e crioterapia no quadríceps femoral e foi constatada uma diminuição da tensão sobre as estruturas moles apenas com o uso do calor 26 . Para o presente estudo, foram selecionados apenas sujeitos do sexo feminino com idades entre 18 e 25 anos.…”

“…Segundo Carvalho et al 27 , as mulheres apresentam uma melhor flexibilidade quando comparadas aos homens. Já para Petrofsky et al 26 , mulheres apresentaram maior flexibilidade e elasticidade de tecidos moles do que os homens com qualquer temperatura aplicada.…”

Transparent Heaters: A Review

“…[ 252 ] Moreover, heating pads can be useful in physiotherapy to help tendons, ligaments, and muscles gain flexibility. [ 253 ] The two currently available technical solutions for thermotherapy are heat packs and wraps. [ 253,254 ] Heat packs are bulky and heavy, and must be preheated in water or in a microwave, often compromising the fine control of the temperature.…”

“…[ 253 ] The two currently available technical solutions for thermotherapy are heat packs and wraps. [ 253,254 ] Heat packs are bulky and heavy, and must be preheated in water or in a microwave, often compromising the fine control of the temperature. Heating wraps allow a better control of the temperature thanks to the Joule heating of resistors, but are usually rigid and heavy, which limits their wearability and their use in hospitals.…”

Low Level Continuous Heat Wraps can Increase the Efficiency of Transcutaneous Electrical Nerve Stimulation for Pain Management

“…Heat has long been established as a means of reducing pain with delayed onset muscle soreness [8,37], back pain [38], neck pain and shoulder pain [5,7,[39][40][41]. It works through the activation of TRPV1 and TPRV4 sensory channels in peripheral nerves by blocking Py and Px purine receptors that mediate peripheral pain [2,3].…”