Muscles that Move the Glenohumeral Joint | Origin, Insertion, Action, & More

The video tutorial explores the anatomy and functions of muscles that produce movements at the glenohumeral joint, excluding rotator cuff and shoulder girdle muscles. It covers the deltoid, pectoralis major, latissimus dorsi, and teres major muscles, detailing their origins, insertions, actions, and innervations. The tutorial also explains the role of these muscles in shoulder movements such as flexion, extension, abduction, and internal rotation.

Which muscle is NOT part of the rotator cuff group?

• Teres Minor

• Deltoid

• Infraspinatus

• Supraspinatus

What is the primary action of the anterior head of the deltoid muscle?

• Shoulder abduction

• Shoulder external rotation

• Shoulder flexion

• Shoulder extension

Which nerve innervates the deltoid muscle?

• Axillary nerve

• Median nerve

• Ulnar nerve

• Radial nerve

The pectoralis major muscle inserts on which part of the humerus?

• Lateral lip of the bicipital groove

• Lesser tubercle

• Greater tubercle

• Medial lip of the bicipital groove

Which head of the pectoralis major is responsible for shoulder flexion?

• Clavicular head

• Sternocostal head

• Abdominal head

• All of the above

What is the primary action of the latissimus dorsi muscle?

• Shoulder abduction

• Shoulder flexion

• Shoulder extension

• Shoulder external rotation

Which nerve innervates the latissimus dorsi muscle?

• Ulnar nerve

• Median nerve

• Axillary nerve

• Thoracodorsal nerve

Where does the teres major muscle originate?

• Greater tubercle of the humerus

• Inferior angle of the scapula

• Lateral lip of the bicipital groove

• Medial lip of the bicipital groove

Which action is NOT performed by the teres major muscle?

• Shoulder extension

• Shoulder internal rotation

• Shoulder abduction

• Shoulder adduction

Why is the teres major not considered a rotator cuff muscle?

• It is not involved in shoulder rotation

• It does not insert on the greater or lesser tubercle

• It is not innervated by the axillary nerve

• It does not originate on the scapula