Chronic Lower Extremity Injury, Muscular Tightness, and Balance

Balance within the human movement system (HMS) involves the skeletal, nervous, and muscular systems (Clark, Sutton, & Lucett, 2015). The body always wants to reach static equilibrium as well as dynamic equilibrium with the coordination of proper normal tension-length, force-coupling, and normal joint arthrokinematics (Clark et al., 2015). The HMS does this by proprioceptively assessing the base of support and center of pressure (Yoo, Park, Yoon, Lim, & Ryu, 2018). Maintaining balance and postural control is an important part of the HMS not just for athlete, but for everyone who wish to be optimally functional (Endo & Sakamoto, 2014; Said, Manaf, Bukry, & Justine, 2015). When an individual present with muscular tightness, coupled with a chronic lower extremity injury, there is dysfunction and altered neuromuscular efficiency (Clark et al., 2015).

The cumulative injury cycle is a perpetual risk cycle that an injured athlete could experience injury again, but it is the muscle mechanoreceptors—the muscle spindles and the Golgi tendon organs (GTO)—that cause the reciprocal inhibition of the agonist and synergist muscles that cause neuromuscular imbalance (Clark et al., 2015). When the muscle afferents provide signals to the joints that are not optimally input to the central nervous system (CNS), the GTO is opt to dictate the tension and rate of tension change within the musculotendinous junction (Clark et al., 2015). With the tightness of the muscle in the lower extremity, the synergistic muscles are compensating, thereby producing an improper balance. Endo & Sakamoto (2014), found that the cumulative injury cycle from the tightness and weaker muscles of the lower extremity could cause injuries in the upper extremities in youth baseball players. 

In another study by Hoch, Staton, & Mckeon (2011), the dorsiflexion range of motion has been shown to decrease after an ankle sprain and other foot injuries. To maintain good posture and balance, the CNS initiates proper stability with neuromuscular control that properly recruit prime movers, not synergists (Clark et al., 2015). When there is a breakage in the lower kinetic chain, the main function of the lower extremity to maintain balance and gait would perform sub optimally (Said et al., 2015). The body will always try to compensate to balance the loads on muscles and joints to maintain postural stability.

With these lower extremity injuries with foot and ankles, one of the methods to improve balance and regain stability is to stretch the muscles that are connected to the joints (Hoch, Staton, & Mckeon, 2011). Good balance and posture require an optimal kinetic chain with a combination of ankle, knee, and hip working together to maintain equilibrium (Clark et al., 2015). The factors for muscle tightness and balance deficits, and additional known injuries, must be assessed together, and not individually. Because the proprioceptive nature does not belong only to the muscles, other internal peripheral neural mechanisms also help each part of the body to interact to maintain balance (Hubbard, Kramer, Denegar, & Hertel, 2007; Clark et al., 2015).

But there is hope to gain back the functional balance with proper training. Of course, the first step is to progressively train in a safe stabilization exercises to building functional strengths in balance (Clark et al., 2015). Strength training can improve balance, but balance and agility training with systematic diligent can improve and correct one’s balance deficits (Yoo et al., 2018). Once again, the body always want to get back to equilibrium!

References
Clark, M., Sutton, B. G., & Lucett, S. (2015). NASM essentials of sports performance training. Burlington, MA: Jones & Bartlett Learning.

Endo, Y., & Sakamoto, M. (2014). Relationship between lower extremity tightness and star excursion balance test performance in junior high school baseball players. Journal of Physical Therapy Science, 26(5), 661-663. doi:10.1589/jpts.26.661

Hoch, M. C., Staton, G. S., & Mckeon, P. O. (2011). Dorsiflexion range of motion significantly influences dynamic balance. Journal of Science and Medicine in Sport, 14(1), 90-92. doi:10.1016/j.jsams.2010.08.001

Hubbard, T. J., Kramer, L. C., Denegar, C. R., & Hertel, J. (2007). Correlations among multiple measures of functional and mechanical instability in subjects with chronic ankle instability. Journal of Athletic Training, 42(3), 361-366.

Said, A. M., Manaf, H., Bukry, S. A., & Justine, M. (2015). Mobility and balance and their correlation with physiological factors in elderly with different foot postures. BioMed Research International, 2015, 1-7. doi:10.1155/2015/385269

​Yoo, S., Park, S., Yoon, S., Lim, H. S., & Ryu, J. (2018). Comparison of proprioceptive training and muscular strength training to improve balance ability of taekwondo poomsae athletes: A randomized controlled trials. Journal of Sports Science and Medicine, 17, 445-454.