The teres major (L. teres, round and long ; major, larger.) is a thick, rounded muscle in the posterior shoulder region. It acts on the shoulder joint, with its main function as a synergist in shoulder adduction. It is classified as a one of the scapulohumeral (intrinsic shoulder) muscles, and is visible on the surface …
The subscapularis (L. sub, beneath ; scapularis, shoulder blade.) is the largest of the four rotator cuff muscles. As its name suggests, it is situated on the underside of the scapula. It acts on the shoulder joint and is the prime mover in shoulder internal rotation. It also promotes shoulder stability by resisting anterior translation …
The serratus anterior (L. serratus, saw ; anterior, front.), named for its saw-like appearance, is located on the side of the ribcage. It acts on the scapula and is the prime mover in both scapular protraction and scapular upward rotation. It’s also a key scapular stabilizer, keeping the shoulder blades against the ribcage when at …
The rhomboid major and minor (L. rhomboideus, parallelogram ; major, larger ; minor, smaller.) are two muscles located between the shoulder blades and spinal column. If you took geometry, you might’ve guessed that they’re named after the rhombus shape, which they both resemble. Acting on the shoulder blades, both of these muscles are prime movers …
The levator scapulae (L. levator, elevator ; scapulae, shoulder blades.) is a strap-like muscle in neck and shoulder region. It acts on the scapula and cervical spine, and as its name reveals, its most prominent role is scapular elevation. Classified as a superficial posterior axioappendicular (extrinsic shoulder) muscle, the levator scapulae is situated deep to …
The latissimus dorsi is the largest muscle in the upper body and the widest muscle in the entire body. It acts mainly on the shoulder joint, being the prime mover in both shoulder adduction and shoulder extension (and a strong synergist in internal rotation). Being such a broad muscle that crosses multiple joints, the latissimus …
The infraspinatus (L. infra, below ; spinus, spine [of scapula]) is a thick rotator cuff muscle covering the majority of the posterior surface of the shoulder blade below the scapular spine. It is a prime mover in shoulder external rotation and plays important roles in shoulder stability. Most notably, it prevents excessive anterior and posterior …
The erector spinae (erigere, to erect ; spina, spine.) consists of three long, thin muscle groups running vertically up each side of the vertebral column: the iliocostalis, longissimus and spinalis. These muscles act on different segments of the vertebral column (i.e. lumbar, thoracic, cervical). Collectively, they are the prime movers in spinal extension and spinal …
Discover the muscle anatomy of every muscle group in the human body. Find the best weight lifting exercises that target each muscle or groups of muscles. You can click the links in the image, or the links below the image to find out more information on any muscle group. Abdominals | Biceps | Calves …
The external oblique (L. externus, external ; obliquus, oblique.) is a broad, flat sheet of muscle on either side of the abs. It is named after its location (external to the internal oblique) and its fiber direction (oblique relative to the midline of the body). It is the prime mover in spinal rotation, and it …
External Oblique Muscle: Functional Anatomy Guide Read More »
