Ever found yourself following your physiotherapist’s instructions to “Hold it right there,” “Lower it slowly,” or “Push upwards with energy” during a rehabilitation session? You’re not alone. These directives are part and parcel of injury rehab, often reflecting various stages of recovery and the specific goals of different exercises. But why do physios emphasise these seemingly peculiar movements, such as maintaining an awkward pose or using one leg for lifting and the other for lowering?
The rationale for incorporating isometric (holding), eccentric (lengthening), and concentric (shortening) exercises into rehab protocols is rooted in how they apply different types of stress or load to injured tissues, achieving diverse outcomes.
Static loads, such as those experienced during isometric exercises, can significantly mitigate tendon pain and even provide short-term pain relief. These exercises are especially beneficial for sore, irritable tendons, allowing individuals to participate more effectively in rehab or sports activities. The phenomenon of stress relaxation, where the tendon fibres gradually unwind under sustained load, plays a crucial role here, though it's sometimes avoided in the early stages of injury to protect the delicate tissue.
Physiotherapists often highlight the importance of "heavy, slow eccentrics" or controlling the muscle’s lengthening phase during early rehab. Eccentric contractions are more efficient and consume less energy than concentric ones, making them ideal for early rehabilitation. They allow for a higher force production, providing a strategic advantage when aiming to overload the muscle before it's fully capable of completing an entire movement.
As rehabilitation progresses, the focus shifts towards enhancing muscle power through fast, explosive concentric movements. This phase aims to increase neural drive and maximise force production in a brief period. Achieving this requires a solid foundation of muscle strength and healthy, robust tendons, thus it typically features towards the later stages of rehab.
Physiotherapists meticulously design exercise regimens to achieve specific physiological outcomes, manage pain, or adapt to the unique load-bearing capabilities of the injured tissue. By strategically applying the right type of movement at the appropriate stage of recovery, they ensure optimal rehabilitation outcomes.
Scientific research supports these practices, underscoring their effectiveness in tissue repair, pain reduction, and the enhancement of muscle and tendon function. Whether it’s the immediate pain relief offered by isometric holds, the muscle-building efficiency of eccentric actions, or the strength and speed cultivated through concentric exercises, each method plays a vital role in the journey back to health and performance.
By expertly navigating the complexity of isometric, eccentric, and concentric exercises, physiotherapists in Australia and beyond provide not just immediate symptomatic relief but also long-term recovery and resilience against future injuries.
References
Baar, K. (2019). Stress Relaxation and Targeted Nutrition to Treat Patellar Tendinopathy. Int. J. Sport Nutr. Exerc. Metab., 435-457.
Franchi, M., Reeves, N., & Narici, M. (2017). Skeletal Muscle Remodeling in Response to Eccentric vs. Concentric Loading: Morphological, Molecular, and Metabolic Adaptations. Front. Physiol., 1-13.
Khan, K., & Scott, A. (2009). Mechanotherapy: how physical therapists' prescription of exercise promotes tissue repair. Br J Sports Med, 247-251.
Rio, E., Kidgell, D., Purdam, C., Gaida, J., Moseley, L., Pearce, A., & Cook, J. (2015). Isometric exercise induces analgeisa and reduces inhibition in patellar tendinopathy. Br J Sports Med, 1277-1283.
