Episode 95: How Does Muscle Slack Impact Force Development?

This week we discuss limiters for rapid force production, specifically muscle slack. This narrative review breaks down the 6 processes that happen when contracting a muscle, and focus on the areas of potential delay. Muscles that do not have any pretension must first take up slack before being able to exert force, which could increase a mechanical delay time up to 100 milliseconds. This is important because a powerful action takes less than 300 milliseconds, and the athlete that can exert force quicker is going to have better performance. The authors talk through 3 strategies to reduce muscle slack by pretensioning: a countermovement, use of external load, and agonist/antagonist co-contraction. However, co-contraction is likely the most viable strategy in most athletic contexts. Therefore, practitioners may want to cue for or constrain movement so there is co-contraction. Listen to the episode to hear some strategies we use clinically to limit muscle slack!

The abstract can be found here: https://journals.lww.com/nsca-scj/fulltext/2016/10000/influence_of_muscle_slack_on_high_intensity_sport.7.aspx

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