What is eccentric strengthening?
According to Medical Dictionary (2009), an eccentric movement is the overall controlled lengthening of a muscle in response to an external force. Concentric movement is what we traditionally think of when strengthening. Concentric movement is when the muscle contracts to move the external force (ex: initial movement of a bicep curl). What is the functional difference between the two? Think of when you pick up a glass of water to drink. The movement you make with your arm to bring the glass up to your mouth to drink is a concentric contraction of the bicep. When you’re finished drinking you carefully lower the glass in a controlled manner so that you do not spill the water… or worse… break the glass when you put it back on the counter! That return would be an eccentric contraction. The glass (and gravity) being the external force lowering the arm while the bicep controls the decent as it lengthens!
Eccentric strengthening has been the subject of several studies and has proven to be a very effective approach to strengthening in not only a therapeutic setting but athletic training settings as well. Eccentric strengthening has proven to facilitate healing of soft tissue by modulating tissues containing nerve cells while encouraging collagen production and alignment (Chen et al., 2021). When a damaged tendon is subjected to forces that exceed the tolerable limits, this can result in degeneration of the tendon prolonging pain and dysfunction (Chen et al., 2021). Eccentric strengthening is considered a safer form of strengthening in the rehabilitation setting due to the decreased stress on the damaged or degenerative tendon (Chen et al., 2021).
Why is it safer?
This is safer because the muscle works as it is being stretched and elongated by the external force. This puts less stress on the effected tendon allowing it to safely sustain a controlled load while strengthening, promoting healing, and reducing pain (Chen et al., 2021).
What diagnoses could you use eccentric strengthening for?
General weakness
General global strengthening
To learn more about these diagnoses, check out our diagnoses database here.
References
Chen, Z., & Baker, N. A. (2021). Effectiveness of eccentric strengthening in the treatment of lateral elbow tendinopathy: A systematic review with meta-analysis. Journal of Hand Therapy, 34(1), 18–28. https://doi.org/10.1016/j.jht.2020.02.002
eccentric exercise. (n.d.) Medical Dictionary. (2009). Retrieved August 4 2021 from https://medical-dictionary.thefreedictionary.com/eccentric+exercise