Shoulder Flexion Muscle Test

Muscle Testing for Shoulder Flexion

• The coracobrachialis muscle is considered an accessory muscle during shoulder flexion.
• The range of motion (ROM) for shoulder flexion is 90°.

Therapist's Position and Patient Instructions

• The therapist should stand at the patient's side during the muscle test for shoulder flexion.
• The patient should be instructed to flex their shoulder against gravity.

Muscle Grading Criteria

• Grade 5 (Normal) muscle test requires full range of motion against gravity and maximum resistance.
• A patient who completes the test range of 90° but tolerates no resistance is graded 3 (Fair).
• A patient who completes partial range of motion as this is against gravity during shoulder flexion muscle testing is graded 2 (Poor).

Primary Muscle and Substitution

• The anterior deltoid muscle is primarily responsible for shoulder flexion.
• If the patient attempts to flex the shoulder with the biceps brachii by first externally rotating the shoulder, the biceps brachii is being substituted for shoulder flexion.
• If the patient attempts substitution with the pectoralis major, it results in horizontal adduction.

Alternate Test and Patient Positioning

• If the patient is unable to sit, the alternate test for Grades 2, 1, and 0 in shoulder flexion can be performed with the patient in a supine position.
• For Grade 1 (Trace) in shoulder flexion muscle testing, the patient's arm should be positioned in horizontal abduction.
• For Grade 2 (Poor) in shoulder flexion, the arm should be kept in adduction to avoid attempted substitution by the biceps brachii.

Muscle Characteristics

• The coracobrachialis muscle cannot be isolated, nor is it readily palpable.