Understanding that the foot and ankle complex has the greatest contributing factor to the Human Movement System, hence the greatest influence on each of the systems that Clark et al (2011) describe, any arthrokinomatic dysfunction or muscular imbalance, such as a decrease in control over the medial longitudinal arch, can result in an altered mechanical approach to the HMS leading to a possible cumulative injury cycle(Clark et al, 2011). As described by Clark and Lucett, in order for the body to operate in optimal neuromuscular control, there are three factors that must be in proper position:
- optimal length-tension relationship: which correlates to the amount of tension a muscle can produce at its resting length.
- Optimal force-couple relationship: which are the synergistic muscles or helper muscles that help produce force around a joint at different angles.
- Normal joint arthokinematics: which occurs when there is proper length-tension relationship and optimal force-couple relationships.
These three components, described by Lucett and Clark, provide optimal sensorimotor, neuromuscular efficiency, and optimal tissue recovery. When there is a deviation from them, the result is an altered joint dysfunction that creates an altered relationship of aforementioned components of the Human Movement System (HMS).
The medial longitudinal arch is a “load-bearing and shock-absorbing structure of the foot,” as described by Neumann. This arched configuration provides the bones the ability to receive and diminish the excessive loads that are placed on the body during impact situations, such as running and jumping. During neutral stance on healthy feet, the connective tissue of the longitudinal arch is optimal to support the body weight without the integration of intrinsic and extrinsic muscles of the foot (Neumann, 2011). When the longitudinal arch is not able to support the pressure of the body weight, this can result in “flat feet” or Pes Planus. A person with pes planus, lacks the ability of the foot to dissipate loads, and requires intrinsic and extrinsic muscles of the foot to engage to help compensate for the lack of tension in the connective tissue. Neumann states that even during standing that the client may develop fatigue and overuse symptoms, such as “shin splints,” bone spurs and plantar fasciitis. Hyperpronation, as defined by Khamis et al(2006), is “the rear foot pronation that is excessive, prolonged, and as a result, causing the foot to remain in maximum pronation, too late or never resupinate in terminal stance for push off (Khamis et al, 2006)”. The kinematic dysfunction of the foot will throw the tibia into internal rotation which puts the hip into internal rotation and a flexed position, causing genu valgum and increasing the Q-Angle of the hip joint. This kinetic dysfunction places the hip into anterior pelvic tilt and lordosis of the spine.
Throughout this kinetic dysfunction of the Human Movement System places the body into a neuromuscular dysfunction creating synergistic muscles to become over-stressed and introducing muscle injuries throughout multiple joint locations. Understanding the principal of Optimal Length-Tension Relationships of the intrinsic muscles of the foot and ankle and help restore strength and mobility to the ankle joint, reducing possible injuries along the kinetic chain of movement.
If you want to learn more and how to correct, make sure you visit my site to register for the Live Workshop on Saturday October 20th at 9am EST.
Clark, Michael, and Scott Lucett. NASM Essentials of Corrective Exercise Training. Philadelphia, PA: Lippincott Williams & Wilkins, 2010. Pr
Denegar, C., Hertel, J., & Fonseca, J. (2002). The effect of lateral ankle sprain on dorsiflexion range of motion, posterior talar glide, and joint laxity. Journal of Orthopaedic and Sports Physical Therapy, 32(4), 171.
Clark, Michael and Scott Lucett, NASM Functional Anatomy Presentation, Unit 3 Handout. Print.
Khamis, Sam and Yizhar, Ziva, Effect of feet hyperpronation on pelvic alignment in a standing position, Gait and Motion Analysis Laboratory, Dana Children’s Hospital, Tel Aviv, Israel, September 14, 2005.