By Dr Paul Batman, PhD.
The subscapularis is named according to its position on the scapula. It runs in front of the scapula across the chest wall and attaches on the front of the humerus. Its tendon merges with the joint capsule of the shoulder joint and helps stabilize it.
Subscapular fossa on the anterior scapula.
Lesser tubercle on the anterior humerus.
The subscapularis belongs to the following muscle groups:
Shoulder joint medial rotators, shoulder joint extensors, shoulder joint adductors.
Lat. pulldown (helper), one arm dumbbell row (helper), t-bench medial rotate.
CASE STUDY STRENGTHENING EXERCISE: LAT PULLDOWN.
1. Position yourself directly underneath the bar of a lat pulldown machine
2. Depending on the machine being used you can either sit or kneel under the bar
3. Contract your abdominals to protect your lower back
4. From this starting position pull the bar down in front of or behind your head to either the top of your shoulders or chest
5. Pause in this position and then slowly move the bar back to the starting position
Lat and triceps stretch. An extremely difficult muscle to stretch because of its position on a moving scapula.
CASE STUDY STRETCHING EXERCISE: LAT AND TRICEPS STRETCH
1. Stand in an upright position with your arms by the side of your body
2. Raise your right arm to the side of your body and place it behind your head with your right elbow bent
3. Grasp your right elbow with your left hand and gently push it down and towards your head
4. Hold the stretch for approximately 20 seconds and then return your right arm to the starting position
5. Repeat the stretch on your left arm
Lie a subject face down on a bench with the right arm hanging over the edge. Have the subject medially rotate the shoulder joint. At the same time palpate the subscapularis deep in the axilla near the humerus.
1. The subscapularis is one of the rotator cuff muscles that stabilize the shoulder joint. It works with the infraspinatus and teres minor to pull the humeral head down during flexion and abduction of the shoulder joint. It works particularly well in preventing shoulder joint dislocation during forced lateral rotation when the arm is abducted.
2. The subscapularis is most active in medial rotation when the arm is by the side of the body, making it antagonistic to the teres minor and the infraspinatus.
3. Its greatest involvement in adduction of the shoulder joint is at approximately 90 degrees.
4. The subscapularis contributes as a helper in shoulder joint extension, as seen in a narrow arm pull up with a supinated grip.