External force that is applied to the human body can impose stress on tissues. The adaption of the stress that is placed on the musculoskeletal tissue is a response from the force of stress. This excessive stress on a tissue is through a single episode or multiple episodes that have re-occurred over time. An excessive force that impacts an athlete at high velocity often results in a traumatic rupture of tissue or other injuries (F=MA, Force has both mass and acceleration). Results from injury that occur over time, is considered to be an overuse injury, and this may predispose the athlete to a traumatic injury in the future (Denegar, E. Saliba, & S. Saliba, 2016).
In contrast to deep heating modalities, superficial heating typically does not work on deep rooted injuries such as deep tissues or muscles due to the hypodermic layers of the skin and anything beneath it. Inferior to the skin, the subcutaneous layer of fat works as a thermal barrier that insulates and inhibits heat transfer (Klein, 2013). In comparison to heat modalities, therapeutic cold applications (cryotherapy) is also applied to athletic injuries. Upon application of this method the basic and most common effects are to help reduce swelling/ edema, burns, spasticity, muscle spasms, restricted knee flexion and more.
Superficial heat is one of the most common modalities for patients who are experiencing tension and hypertonicity (high pressure of body fluids). Often times, superficial heat such as hot packs or heating pads are used as inappropriate methods, such as low back pain or muscle soreness that may be caused from exercise (New York, n.d.). Due to the effects of the injury taking time to be felt by the patient (hours after the site is injured) the superficial heat my not be traced to the injury area, which implies that it may not be beneficial. Education and knowledge of superficial heat and cold modalities are important for both the patient and the professional to understand.
The Use of Heat
Heat is commonly used for its soothing and palliative effects. Although these benefits are distinguished among many, the other benefits of heat is “increased extensibility of collagen, decreased joint stiffness, relief of muscle spasm, reduced inflammation, edema, exudates and increased blood flow” (New York, n.d.). Applying heat prior to exercise and stretching may help muscle fibrosis and contracted joints increase flaccidity. It has been noted through research that moist heat does not influence involuntary motoneuron pool recruitment anywhere from 1-30 minutes after application. Any decrease in recruitment of motoneurons from moist heat applications have been questioned for the ability of an injured athletes return to competition. Through research, it remains that moist heat has not affected this ability of an athlete's performance (Long & Hopkins, 2009).
The Use of Cold
In contrast like heat, cold can also be used to ease pain. During the process of acute injuries, bleeding, inflammation, and swelling occur around the injured site. Obviously, these occurrences should be immediately reduced in the case of a serious medical condition like excessive bleeding. Aside from the inflammation that takes place to help protect and heal the injury, it can be extremely painful to the athlete. In this case, ice can be applied to “cool the tissues, reduce their metabolic rate and nerve conduction velocity and cause vasoconstriction of the surrounding blood vessels” (Sports Injury Clinic, n.d.).
Understanding the complexities of the healing process is vital for all professionals involved in the care of an injured athlete. “The quality of repair can be quite variable depending upon the extent of injury, vascular status of tissue, function of resident cells, and the person’s overall health. That is to say, not all tissues heal similarly, and different patients’ healing capacity depends on many local and systemic factors” (Denegar, E. Saliba, & S. Saliba, 2016, p 82).
Denegar, C.R., Saliba, E., & Saliba, S. (2016). Therapeutic modalities for musculoskeletal injuries(4th ed.). Champaign, IL: Human Kinetics.
Klein, M. (2013, August 28). Superficial heat and cold. Retrieved from website http://emedicine.medscape.com/article/1833084-overview
Long, B.C., & Hopkins, J.T. (2009, August). Superficial moist heat’s lack of influence on soleus function. Journal of sport rehabilitation, 18(3), 438-447. Retrieved from EBSCOhost.
New York, Chiropractic College. (n.d.). Chapter 4- Physiological therapeutics: Superficial heat. Retrieved from http://www.nycc.edu/webdocs/ic/IQA/IQAFiles/Protocols/Chapter4/SuperficialHeat4_2.pdf
Sports Injury Clinic. (n.d.). Hot vs cold therapy. Retrieved from website http://www.sportsinjuryclinic.net/treatments-therapies/cryotherapy-cold-therapy/hot-cold-therapy