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Corrective Exercise Is Functional - Part 2


This article is a continuation from Part 1....

Although working with clients in pain for the purpose of “treating” or “fixing” their pain is outside the scope of practice of the fitness professional, this does not mean that our clients do not have active symptoms. Many clients feel they have exhausted treatment options or have plateaued with their care. Managed care and capitation that has limited visits for physical therapy has created a new demographic seeking personal training. Add the aging baby boomer generation and the health history profile of many personal training clients is increasingly more complex. These individuals still want to be healthy, physically active, functional and productive. The appropriate training progressions can help them do that.

There is a critical point here I would like to emphasize. In my observations, many fitness professionals have adopted the "Far Right (FR)" philosophy, not recognizing the full complement of tools that a physical therapist or chiropractor - who also uses the FR philosophy - utilizes as part of their intervention. Aside from having a more in-depth education on joint mechanics, tissue tolerance, etc., physical therapists and chiropractors also apply joint mobilization, joint distraction, manual resistance and even orthotics to enhance what they will do with fully integrated, multiplanar exercises.

Following comprehensive assessments on their patients, these medical professionals will use these various other “tools” to prepare the patient’s body for fully integrated, multiplanar exercises. These tools are used to address dysfunctions at the local level to improve the global response. The fitness professional who applies exercise strategies from the FR philosophy without addressing the local segmental dysfunctions first provides the body an environment to perpetuate compensatory movement patterns.

The appropriate application of corrective exercise can produce benefits similar to many manual interventions. In fact, from a motor learning perspective, the benefits of corrective exercise can be even superior to manual intervention because the client can reproduce the benefits independently of the health professional. This allows for more frequent and proactive changes by the client that can not occur with manual interventions performed two or three times a week. This is assuming the fitness professional has the prerequisite knowledge of functional anatomy and application of specific corrective exercise.

A fitness professional who does not assess musculoskeletal function or who does not have a thorough understanding of the results of an assessment may incorrectly believe that getting an exercise done is the same as getting an exercise done right. Or that if an exercise does not produce immediate pain, it is not doing any harm. The reality is that cumulative mechanical stress from inappropriately applied functional exercises is the same as cumulative mechanical stress from any other activity.

Proprioceptive Flow Following Injury

The ligaments and joint capsules contain mechanoreceptors that provide feedback on joint position and acceleration. Certain mechanoreceptors also contain pain receptors. When a ligament or the joint capsule is injured, the amount and quality of proprioceptive information is reduced. During the healing process, scar tissue forms. The properties of scar tissue are not the same as the original ligament tissue. Therefore, proprioceptive information remains reduced, unless the injury was followed by a comprehensive rehabilitative process that challenged the local proprioceptive system.

Unless you are working with high level athletes, how many of your clients have gone through comprehensive proprioceptive training following an injury? Many people won’t even go to a doctor for a diagnosis following a sprain, never mind therapy.

Muscle spindles will adapt to injury as well. Edgerton et al. studied the muscle activation of spinal muscles during a variety of motor tasks in whiplash patients. Their research showed an under activity of agonists and over activity of synergist. They concluded that the nervous system can detect a reduced capacity to generate force from a specific muscle or muscle groups and compensate by recruiting more motor neurons. This compensation is achieved by recruiting more motor units from an uninjured area of the muscle or from other muscles capable of performing a similar task (synergist).

Babyar looked at a population that had experienced shoulder pain. As part of the patient’s compensation strategy, they elevated their scapula when the arm was raised. Patients were reevaluated after the shoulder pain was gone. Babyar observed that the scapular elevation continued even in the absence of pain.

Janda also describes muscles that have a low irritability threshold. These are posturally shortened and hypertonic muscles. These muscles will create a bias of the motor neuron pool and are prematurely active (or overactive) and exert inappropriate influence on selected movements.

Interestingly, joint range of motion (ROM) may return to pre-injury levels after the ligament or joint capsule heals. But ROM does not correlate directly with proprioceptive flow from the mechanoreceptors. Therefore, even if a previously injured joint has normal ROM, it may not be “feeding” the necessary proprioceptive information to the CNS during activity. Our internal feedback systems are based on the quality of the proprioceptive information we receive. Therefore, poor proprioceptive flow from the periphery will negatively affect the quality of the motor response based on that poor proprioceptive information.

For example, the client or athlete with a history of ankle sprains that were never rehabilitated properly will have poor proprioceptive flow from the damaged ligaments. The body will not sense the “stuck” talus that is inhibiting adequate dorsi flexion during midstance in gait. The body unconsciously figures out the best way to maintain equal stride lengths is by prematurely lifting the heel on the affected side during the stance phase. This creates biomechanical changes at the hip and lumbar spine.

Also associated with joint injuries are two muscular responses resulting from disruption of the joint integrity. Both are unconscious and neurologically based. One response is reflex spasming. This is a response to pain in which the muscles splint via co contraction around the joint to protect it by reducing movement and minimizing additional damage. Motion required at the protected joint must be transferred to joints proximal and distal to the protected joint.

An alternate response by the CNS is reflex inhibition. This is the complete opposite of spasms. As the result of the arthrogenic reflex, the muscles surrounding the joint become inhibited. This often follows distention of the joint due to effusion (swelling). Inhibition prevents the body from using that joint, thereby avoiding any potential additional harm. Biomechanical compensation is therefore necessary to compensate for the weak link.

An often overlooked example of this is the role a blocked sacroiliac (SI) joint has on the function of the ipsilateral gluteus maximus, internal oblique and multifidus. If the appropriate movement of the sacrum on the innominate does not occur, the activity of these three vital lumbo-pelvic stabilizers is delayed due to inhibition by the CNS. Force production is secondary to appropriate timing of muscle activation for joint stabilization. The role of the SI joint is critical in load transfer of forces from the ground to the upper body. Poor load transfer through the SI joint requires compensatory reactions at the knee, hip and lumbar spine, compromising optimal lumbo-pelvic stabilization.

Therefore, it is questionable if, for example, an anterior lunge with the trunk flexed forward can improve gluteus maximus function if the SI joint is blocked on the same side. According to Hungerford’s study, there is more likely to be an earlier onset and increase in activity of the biceps femoris, also a hip extensor. Clearing the SI joint with the appropriate corrective exercises prior to lunging will facilitate appropriate timing of gluteus maximus function in the lunge.

Stay tuned for the third and final part of this series... coming soon!

References:

  1. Babyar SR: Excessive scapular motion in individuals recovering from painful and stiff shoulders: causes and treatment strategies, Physical Therapy 76:226, 1996
  2. Brooks, VB The Neural Basis of Motor Control. New York: Oxford University Press 1986
  3. Edgerton, VR., Wolf, SL., Levendowski, DJ., Roy, RR. (1996). Theoretical basis for patterning EMG amplitudes to assess muscle dysfunction. Medical Science in Sports and Exercise 28: 744-51.
  4. Hungerford B, Gilleard W, Hodges P 2003 Evidence of altered lumbopelvic muscle recruitment in the presence of sacroiliac joint pain. Spine 28(14):1593
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  8. Magill, RA, (2001). Motor learning: Concepts and applications. New York. McGraw-Hill, 2001
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