Justifying the “Physical” in Physical Therapy
Physical therapists have long identified that exercise and mechanical forces can provide therapeutic effects, and many patients are familiar with the idea that physical therapy will likely have a component of exercise. However, as I have found with talking to many patients, the quantity and degree of difficulty in exercise can vary from clinician to clinician, even while treating the same ailment. This discrepancy can be very confusing and frustrating for people with pain, often perpetuating their skepticism for exercise. As a physical therapist it can feel like a challenge to get patients to keep compliance with exercise programs that could be perceived as too hard, too painful, or not quick enough in alleviating their condition. This is why it is important for our profession to talk with our patients, answer questions, and take time to provide the necessary education and reasoning about why exercise is important for tissue health.
The musculoskeletal system absorbs, generates, and transmits forces through your body to allow fluid-like movement. When you stand from a chair, go up stairs, or jump up and down, these mechanical loads are transferred to the tissue of your muscles, tendons, joints, and bones. When a physical therapist prescribes exercises, they are using this concept, known as “mechanotherapy,” to reduce or reverse injury to damaged tissue and promote the production of healthy tissues. (1). But what is actually happening inside these tissues and why is it important to our patients?
In 2009 Khan and Scott (2) published a paper in the British Journal of Sports Medicine outlining this precise process. When movement or a mechanical load is applied to a tissue, proteins known as “integrins” change shape and deform the cell’s nucleus. This creates a biochemical cascade of events which informs the nucleus to send and incorporate more protein into the cell’s wall, altering mass, structure, and tissue quality. These physical changes then allow the cells to maintain integrity and more effectively distribute future loads.
As published in the British Journal of Sports Medicine by Khan and Scott (2)
Each tissue type will respond to different types of forces. Muscles will stretch and contract, tendons will pull and be compressed, and bone will absorb vertical compression from activity, body weight, and gravity. Each tissue will respond differently to amounts and rate of force, and will require varying times to recovery and rebuild after loading. Understanding this biological process is important to all aspects of physical wellness, including rehabilitative care, injury-prevention training, and performance training. It has been well documented that a reduction in or sudden and excessive increase in mechanical loading of the body can lead to a wide range of musculoskeletal disorders ranging from osteoporosis, osteoarthritis, muscle atrophy, and tendinopathies. (3) Depending on your needs, a physical therapist can teach you to use a variety of exercises to provide each tissue with an optimum amount of mechanical force that will stimulate positive change. The human body is a robust, adaptable, and amazing organism that we continue to learn and uncover more about. Treat yours well and it will reward you.
References:
1. Huang C, Holfeld J, Schaden W, Orgill D, Ogawa R. Mechanotherapy: revisiting physical therapy and recruiting mechanobiology for a new era in medicine. Trends Mol Med. 2013;19(9):555‐564.
2. Khan KM, Scott A. Mechanotherapy: how physical therapists' prescription of exercise promotes tissue repair. Br J Sports Med. 2009;43(4):247‐252.
3. Ingber DE. Mechanobiology and diseases of mechanotransduction. Ann Med. 2003;35(8):564‐577.