Joint dysfunctions that occur in the body begin by a breakdown in optimal neuromuscular control, which is comprised by three major components that occur simultaneously (Clark et al, 2011):
1. A normal length-tension relationship, which happens when the agonist has an optimal length that allows for the most actin and myosin attachments in the sarcomere thus providing optimal force that muscle can create.
2. A Normal force-couple relationships since each muscle involved in the movement of the joint has different attachment points on the bone providing different force to that joint.
3. A altered joint dysfunction leads to altered reciprocal inhibition which Clark et al (2011) define as a decrease in neural drive to an overactive or shortened muscle which decreases the effectiveness of the functional antagonist. This dysfunction leads to our synergistic muscles having to work to produce the necessary force minimized by the intended agonist of the joint movement.These major components of the human movement system allow for proper joint arthrokinematics and reduce impairments in the human movement system.
Without question, each of the components involved is of equal importance in maintaining proper joint arthrokinematics, given that when one is inefficient, the person is susceptible to the cumulative injury cycle. Sahrmann describes this pattern of musculoskeletal health as the pathokinesiologic model (2002). In this model, the path to good musculoskeletal health is categorized into four main components: our muscular and skeletal system; our nervous system, our biomechanical system and our cardiac system. When there is an abnormality in our kinematics, this creates a functional limitation, inducing a movement impairment, which in turn an impairment of its components of the surrounding joints, causing an abnormality leading to an injury (Sarhmann, 2002). Narrowing this down to a single event of importance is impossible, however as building a solid structure begins with its foundation, this is true for our human movement system. Examining the factors of overcoming muscle impairments to create an optimum joint kinematics to the HMS(human movement system): inhibit(altered length-tension relationship), lengthen, activate, integrate; all are of equal importance in disengaging from the cumulative injury cycle.
• Inhibitory techniques such as self myofascial release can help release muscle adhesions that alter the neuromuscular control leading to muscle imbalance and altered force-couple relationships. This altered length-tension relationship may lead to altered muscle recruitment which is caused by altered reciprocal inhibition, in which overactive muscles decreases the neural drive which inhibits recruitment of its optimal antagonistic muscle (Clark et al, 2011). Breaking up these adhesions can help begin to restore normal length-tension relationships of the agonist and antagonist muscle group.
• Lengthening of the muscle that is accomplished through static stretching to restore proper length-tension relationship to help restore proper force-couple relationships thus minimizing synergistic dominance restoring structural and functional efficiency.
• To activate a muscle through isolated strengthening exercises will begin to restore proper neural drive to that specific muscle restoring an optimal force-couple relationship to the muscles of a given joint. Increasing the strength of an injured or underactive muscle will help minimize synergistic dominance to that area restoring optimal joint kinematics.
• Lastly, integrating the underactive or injured muscle is the last important step to decreasing or eliminating muscle impairments or imbalances. Dynamic movements that involve multi-plane involvement help integrate agonist and synergistic muscles throughout a full range of motion and help increase motor unit activation and synchronization to provide optimal neuromuscular control.To summarize, there is no single component that would stress more importance in the HMS to minimize or eliminate impairments, as each add value that prevent entering the cumulative injury cycle thus creating musculoskeletal pain.
Clark, Micheal, and Scott Lucett. NASM Essentials of Corrective Exercise Training. Philadelphia, PA: Lippincott Williams & Wilkins, 2010. Pr
Sahrmann, S. (2002). Diagnosis and Treatment of Movement Impairment Syndromes. St. Louis, MO: Mosby, Inc.