You’re no doubt familiar with the Achilles tendon, named after the Greek demigod whose singular physical weakness brought him to his knees. But how much do you know about tendon functionality? When it comes to mobility, tendons are the unsung heroes of our anatomy. These tough yet flexible cords of fibrous tissue connect muscle to bone—unlike ligaments, which connect bone to bone.
Tendons are found throughout the body, to help facilitate movement. When a muscle contracts, the tendon absorbs some of the impact and pulls the attached bone into action.
Read on to learn more about these heavy lifters:
- A common affliction of the tendon is tendinitis, inflammation or irritation of a tendon. This condition results from sudden injury or repetitive impact on tissue. Tendinitis occurs most frequently in the knee, shoulder, elbow, hip and ankle (WebMD 2018).
- Tendon health can be improved with vitamins A, C, D and E; protein and calcium; B group vitamins; and chondroitin (Stening 2011).
- Tendons vary in size and shape, depending on the function of the attached muscle. Muscles with a higher output of force and strength have short, wide tendons, while muscles that power finer movements are attached to long, thin tendons (Lee, Thomas & Lowe 2017).
- A tendon is made up of dense connective tissue composed of collagen fibers. These fibers are bunched together into primary bundles (subfascicles), groups of which form secondary bundles (fascicles). These in turn are grouped into tertiary bundles (multiple fascicles), and the tertiary bundles make up the tendon. A surrounding sheath of connective tissue (endotenon) helps the bundles glide against one another during movement (Encyclopedia Britannica 2017).
- An estimated $30 billion is spent on musculoskeletal injuries every year in the United States, with tendon and ligament injuries making up about 45% of that cost. Approximately 30%–50% of all sporting injuries involve tendons (Docheva et al. 2015).
- The place where a tendon attaches to muscle is called the musculotendinous junction. The point at which a tendon attaches to bone is known as the osteotendinous junction (Lee, Thomas & Lowe 2017).