Muscle architecture for pennate muscles. Pennate muscles can be further divided into uni-, bi- or multipennate. Unipennate muscles are those where the muscle fibers are oriented at one fiber angle to the force-generating axis and are all on the same side of a tendon. The pennation angle in unipennate muscles has been measured at a variety of resting length and typically varies from 0° to 30°. The lateral gastrocnemius of wild turkeys is an example of this muscle architecture. Muscles that have fibers on two sides of a tendon are considered bipennate. The stapedius in the middle ear of humans, as well
Longus colli muscle cause some whiplash patients to have an unnatural lack of curvature in the patients' neck. Acute calcific tendinitis of the longus colli muscle can occur. This presents with acute onset of neck pain, stiffness, dysphagia and odynophagia, and must be distinguished from retropharyngeal abscess and other sinister conditions. Imaging diagnosis is by CT or MRI, demonstrating calcification in the muscle in addition to retropharyngeal oedema. Treatment is supportive, with non-steroidal anti-inflammatory drugs. Longus colli muscle The Longus colli muscle (Latin for "long muscle of the neck") is a muscle of the human body. The Longus colli is situated on the