The Effects of Fatigue in Hamstring Rehab

Are you considering the effects of fatigue in your hamstring rehab?

We must respect that fatigue, both acute and chronic, changes the way our body organizes movement. Our coordination strategies and force production capabilities will alter due to the changing internal capacities. 

Simply watch a 400m race early in a track and field season and watch how mechanics change as the sprinters round the final curve. 

Too often this part of the process is neglected by the rehab practitioner. However, failing to address this element before returning to play is like creating a full powerpoint presentation and not hitting save. The work done is only as good as the ability to carry it out under varying degrees of duress. 

Following a hamstring strain we must respect the effects of local fatigue on the muscle as well as how systemic fatigue alters movement strategy. Fatigue with sprinting has been shown to focally effect the EMG activity of the biceps femoris, the most often injured of the hamstring muscles, more so than the medial hamstring (Timmins et al. 2014). However, hamstring muscle fatigue will have a diverse pattern depending on activity and contraction type. 

Hamstring injuries have been shown to typically occur later in games (Woods et al. 2004; Brooks et al. 2006; Ekstrand et al. 2011) presumably due to the effects of fatigue. When returning an athlete back to play we must be conscious of the effects of fatigue and spikes in workload, especially in the 6 week window where re-injury risk is particularly high. A high five and good luck is not an appropriate discharge recommendation. We must guide the individual and their coach on a methodical and gradual approach to return to play that respects the effects of fatigue and allows time for re-acclimation. 

Want more info on best practices and nuanced clinical decision making for hamstring strain injuries? Check out our new Hamstring Strain Accelerator Course– now approved for .6 CEUs in 40+ States for Physical Therapists. Get all the Details and Start HERE

Credit: Sun Y, Wei S, Zhong Y, Fu W, Li L, Liu Y. How joint torques affect hamstring injury risk in sprinting swing–stance transition. Medicine & Science in Sports & Exercise. 2015;47(2):373-380.

Brain Fuel Newsletter