How Injuries Occur and the Rehab Triangle

The information in this course can be found in the Understanding Human Movement Home Study Course.


The human body is a complex machine that consists of multiple parts engineered to work and function synergistically. At the helm is the central and peripheral nervous system, which directs traffic in a sense, choreographing gross and precise movements of the musculoskeletal system. The degree of injury that someone sustains is dependent upon the magnitude, duration, and velocity of applied force to the body and the underlying tissues involved. During an examination of a physical therapy patient, the mechanism of injury (MOI) is one of the most important pieces of information that a physical therapist acquires during the history taking. The mechanism gives the clinician a very strong indication of what tissues and structures may have been injured, how the injuries occurred, and the potential severity of these injuries. (Macgee et al 2007)  This information assists the physical therapist in treating all musculoskeletal injuries and movement dysfunctions.
So how does all of this pertain to the 21st century fitness professional? The human body breaks down because of injuries, surgeries, and movement dysfunctions. How can you better understand common injuries, post rehabilitation training, and program design to work with these types of clients? This series of three articles will look at the foundation science, functional assessments, and application of evidenced based movement science. This will help you, the fitness professional understand that having sound information in foundation science, will help your knowledge and understanding of helping all clients.

How Common Dysfunctions Develop
There are several reasons a dysfunction (pathology) develops. It is important for the personal trainer to thoroughly understand all potential causes of how a dysfunction develops. Familiarizing yourself with these different causes will not only strengthen your knowledge and understanding to help the client, but will also assist in the communication with other health care professionals as part of the Rehab Triangle. The rehab triangle is the communication between the client, personal trainer, and physical therapist.

Do not diagnose or try and ‘figure’ out a client’s problem. If you have a client who has an injury or is recently injured, it is important to first refer the client to either a physician or physical therapist for help.

Several common causes of how dysfunctions may develop:

  1. Degeneration due to overuse: Degeneration is simply defined as thinning of a tendon due to micro tears or in essence or the breaking down of a joint surface. For example, a postal worker who repeatedly uses one arm to file mail to one side for many months or even longer, all of a sudden feels a twinge in their medial deltoid for no reason. Another example is a farmer who for years lifted hay a certain way and then starts to experience shoulder pain. Both of these scenarios are examples of strain to a tendon (in this example, most commonly the supraspinatus). Tendonitis if ignored, eventually progresses to a tendinopathy.
  2. Injury or trauma: There are several mechanisms or causes where tissue can be injured. Someone who falls from a ladder will have a greater magnitude of force applied to the body, than someone who misjudges a step and falls. The forces can result in tissue overload that result from acceleration or deceleration injuries (i.e. sprains and strains), repetitive stress or overuse (i.e. repetitive stress injury), compression or crushing (i.e. contusions) or transections (lacerations or surgical incisions). In addition, both static and dynamic movements (i.e. walking, sit to stand) made by the patient, provide the clinician with insight into the irritability and severity of the injury. (Macgee et al 2007)
  3. Surgery: Like cars, individuals break down over time. Clinically, arthritis is common in both men and women, but tends to be more prevalent among those who work as tradesman, carpenters, plumbers, mechanics and similar fields. In these positions, individuals are consistently loading their spine, hips and knees. Whether someone is installing, building, or fixing, the body receives compressive loads (forces) that stress the joint and surrounding tissues. Over time these forces cause muscles to tighten, joints to break down, and eventually lead to the onset of arthritis. The severity of the arthritis is diagnosed by an x-ray. Therefore, an individual’s type of work, lifestyle, injury(s), or all, impact daily function.
  4. Sedentary lifestyle: Being sedentary stresses multiple systems including the cardiovascular, musculoskeletal, and neurological systems.  For example, there is a well established body of literature highlighting the relationship between lack of regular physical activity and hypokinetic diseases such as diabetes mellitus and cardiovascular disease.
  5. Systemic pain: Another source of pain is know as “referred” pain. There are three sources of referred pain that someone may experience. The first is cutaneous pain (related to the skin). Another is deep somatic pain, which is pain related to the wall of the body. Lastly, visceral pain, is pain that includes all body organs of the respiratory, digestive, urogenital, endocrine, spleen, heart, etc. Pain is not well localized in visceral pain because of innervation of the viscera which is connected via nerve endings.
  6. Repetitive stress injury (RSI): are injuries to the musculoskeletal and nervous systems that may be caused by repetitive tasks, forceful exertions, vibrations, mechanical compression, or sustained or awkward positions. ( Injuries come in all shapes and sizes, and are caused by many things. Injuries are classified as either acute (0-7 days), subacute (7-21 days), or chronic (21 days post injury or surgery).

The Rehab Triangle


The rehabilitation triangle is the synergistic connection between the client, personal trainer, and physical therapist (PT). I firmly believe that this relationship is very important. When evaluating a new patient for the first time, PTs are legally by insurance and Medicare standards, required to contact and send a plan of care to a physician. This not only educates the physician with the thoughts’ of the PT, but how the PT will help the patient and why skilled physical therapy is needed. When a PT sends a client your way, communicate and ask questions so you can provide safe and effective after therapy intervention.

Building Relationships

Building relationships with allied health professionals such as physical therapists, massage therapists, chiropractors, physicians, and others is beneficial. A strong referral network provides greater exposure for your training services and opens new client referral pipelines.


Proper training through good continuing education courses and specialization qualification is important when attempting to build these relationships.

Injuries are inevitable.  The landscape of providing fitness services is changing drastically, with qualified fitness professionals taking primary roles in prevention and after care of injury and chronic disease. The avenues for marketing and providing services have never been more robust and the ability to reach many markets is rapidly expanding with advancing technology.

A fitness professional who takes the time to advance their skill set with continued education or by obtaining specialty certifications, who develops professional relationships and delivers quality services informs prospect consumers and other professionals (e.g., physicians, PT, chiropractors) of their level of dedication, training and service quality will help lead to success. 


  • Gellert C. (2018) Understanding Human Movement. Fitness Continuing Education Alliance.
  • Magee, D, et al, 2007, Scientific Foundations and Principles of Practice in Musculoskeletal Rehabilitation, Saunders, pp. 5-10, 25-32.


Chris received his Bachelor’s Degree in Marketing from SUNY Plattsburgh, his Master’s Degree(MPT) in Physical Therapy from Nova Southeastern University and he received his advanced Master’s Degree in Musculoskeletal & Sports physiotherapy from the University of South Australia(equivalent to a U.S. Residency). Uniquely, Chris has been a personal trainer since 1996, changed careers in 1997 from Marketing to Physical Therapy.

His passion for learning is evident and contagious. He loves to present at conferences, private seminars and fitness venues. Chris has earned the prestigious C.S.C.S. credential through the National Strength and Conditioning Association in 2002. Chris has been a practicing physical therapist for 18 years with a strong clinical background in orthopedics, sports injuries and spinal dysfunctions and a personal trainer for 20 years. He has worked in industrial rehabilitation, outpatient, and private practice settings and has also been a fitness presenter for the past 15 years. He has created five dynamic live seminars for personal trainers, physical therapists and massage therapists, five home study and five Elearning courses on human movement. He is presently working as a physical therapist,  presents at fitness conferences, teaches live seminars for PTCS and other continuing education companies while consulting on various fitness and health-related projects.

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