The Lat Test evaluates shoulder flexion which includes the flexibility of the latissimus dorsi muscle group, shoulder joint restrictions and scapular motion limitations. The lat muscle spans the entire back and inserts onto the arm. Tightness in the lat can lead to loss of spinal posture anytime the Latissimus Dorsi Innervation. The lats are innervated by the thoracodorsal nerve, C6,7,8. Assessing Latissimus Dorsi Length. The proper position to assess the length or stiffness of the lats is lying face up on a table. Follow these steps to asses a person's latissimus dorsi length: Lie face up on a flat surface with knees bent to 90?. Zone 3 (Axilla): pectoralis major (anterior wall), latissimus dorsi (posterior wall), ribs 2-6 and serratus anterior muscle (medial wall), bicipital groove of humerus (laterall wall), axillary lymph nodes, brachial plexus, axillary artery Manual Muscle Testing, MMT Manual Muscle Testing was developed for the first time in the world during the 1860-1880 century by Swedish physiotherapists from the Royal Central Institute of Gymnastics (G.C.I.) in Stockholm, Sweden. This university was founded by Pehr Henrik Ling in 1813.It was the first and it was unique, and at the time the leading college for all manual medicine and Lats muscle strains often occur from overuse or trauma, including a direct blow to the muscle or overstretching of the muscle fibers. The latissimus dorsi is often injured during sports activities. For example, this muscle is used during pitching activities — first as a shoulder stabilization during the cocking phase, then as a strong Movement through complete test range in gravity eliminated position and through more than one half of test range against gravity Latissimus Dorsi is often thought of as a shoulder muscle, but it has a major role in trunk movement. When training the core, it's essential to know all of the muscle attachments so you can integrate them into your training program. Having strong core m