If a muscle is overly long or short, what is the likely impact on its function?

When a muscle is either overly long or short, it can lead to diminished force production. The reason for this lies in the mechanics of muscle contraction, specifically the length-tension relationship.

Muscles have an optimal length at which they can produce maximum force, usually referred to as the resting length. When a muscle is elongated too much, it is positioned beyond this optimal length, resulting in fewer cross-bridges forming between the actin and myosin filaments that are essential for muscle contraction. Conversely, if a muscle is too short, the actin and myosin filaments overlap excessively, which also reduces the ability to generate force effectively.

This understanding is crucial for coaching and training, as it helps in designing exercises and strategies that keep muscles within their optimal functional range, thereby maximizing their performance during activities such as running.