Normal Shoulder Range of Motion

Shoulder Range of Motion needs to be assessed actively and passively. This is because patient may have reduced movement in the joint due to pain, weakness, tendon injuries and bony or soft tissue blockade to motion.

In the scenarios with pain, weakness and cuff injury the patient will have reduced active movements, but on testing the movements passively, one would see that the arc of motion is fairly preserved in some cases.

Additionally, the character of the blockade to motion can be assessed passively, with a soft and elastic end point suggesting soft tissue contractures and a firm end point pointing to a bony blockade.

If the patient is able to perform full active movements, there is no requirement for passive testing of movements.

What is the normal Shoulder Range of Motion Degrees?

The following Shoulder ROM need to be tested:

Shoulder Abduction

Normal Range of Shoulder Abduction is 170–180°.

The principle abductors of the shoulder joint are:

1. The middle portion of the deltoid,
2. The supraspinatus.

The secondary abductors are:

1. The anterior and posterior portions of the deltoid,
2. Serratus anterior.

See Also: Shoulder Examination

Normally, the abduction at the shoulder happens via the scapulohumeral rhythm which comprises of movement of the humerus, scapula and the clavicle. This is divided into 3 phases as follows:

Phase 1	– Humerus 30° abduction. – Scapula minimal movement (setting phase). – Clavicle 0–5° elevation.
Phase 2	– Humerus 40° abduction. – 20° of scapular rotation, with minimal protraction or elevation, making a total of 60° of abduction in this phase (2:1 ratio). – Clavicle 15° elevation.
Phase 3	– Humerus 60° abduction and 90° external rotation to clear the greater tuberosity from the acromion process. – Scapula 30° rotation (2:1 ratio). – Clavicle 30–50° posterior rotation and up to 15° elevation.

Shoulder Adduction

Shoulder range of motion for shoulder Adduction is normally 50–75°.

The primary adductors are:

1. The Pectoralis major
2. The Lattisimus dorsi.

The secondary adductors of the shoulder joint are:

1. The Teres major
2. The Anterior portion of the deltoid.

To accomplish Shoulder Adduction movement, the patient first flexes the arm to 90° and then moves the arm across the front of the body.

The examiner should watch the relative amount of scapular movement. If movement is limited in the glenohumeral joint, greater scapular movement will be seen.

On testing the passive adduction movement after stabilizing the scapula with the palm on the acromion and spine of scapula from behind and keeping the elbow flexed, terminally the patient may show pain in the front of the shoulder.

This is known as the Cross Body Adduction test and this signifies pathology of the acromioclavicular joint.

Shoulder Forward Flexion

Shoulder ROM for Forward Flexion is normally 160–180°.

The primary shoulder flexors include:

1. Anterior portion of the deltoid muscle
2. The coracobrachialis.

The secondary shoulder flexors include:

1. Pectoralis major
2. The biceps muscles.

To passively test flexion, stand behind the patient and stabilize the scapula by keeping the palm on the acromion and hold the arm above the elbow using the other hand.

Shoulder Extension

Normal Range of shoulder extension is 50–60°.

Primary shoulder extensors are:

1. Latissimus dorsi,
2. Teres major
3. Posterior portion of the deltoid.

Secondary shoulder extensors are:

1. Teres minor
2. Triceps long head.

Stay behind the patient with one hand on the acromion to stabilize the scapula and with the other hand hold the arm above the elbow and extend the shoulder passively.

Shoulder External Rotation

Normal shoulder ROM for External Rotation is 80–90.

The primary external rotators include:

1. The Infraspinatus,
2. The Teres minor.

The secondary external rotator is the posterior portion of the deltoid muscle.

The examiner moves to the front of the patient and asks the patient to flex both his forearms and the examiner stabilises both elbows into the waist to prevent the patient from substituting with adduction. The patient is now asked to rotate his arms outwards.

This can be passively tested one side at a time by continuing the stabilization of the elbow into the waist and holding the forearm with the other hand and moving it outwards.

See Also: Hip Range of Motion & Biomechanics

Shoulder Internal Rotation

Normal shoulder ROM for Internal Rotation is 60–100°.

The primary internal rotators of the shoulder are:

1. The Subscapularis,
2. Pectoralis major,
3. Lattisimus dorsi
4. The Teres major.

The secondary internal rotator of the shoulder is the anterior portion of the Deltoid.

Maintain the position as described for testing external rotation, the patient is asked to rotate his arms inward. If he/she is able to bring up to his abdomen, ask him/her to take the forearm behind his back.

For testing passive internal rotation, assume the position as described for testing passive external rotation and then move rotate the arm inward.

Once the abdomen is reached the forearm can be taken to the back.

A quick method to test all the above mentioned movements of the shoulder is to perform the Apley’s Scratch test.

Scapular Elevation (Shoulder Shrug)

The primary elevators are:

1. The Trapezius
2. Levator scapulae.

The secondary elevators include the Rhomboids.

Stand behind the patient and ask the patient to shrug. Note the scapular elevation and the contraction of the muscles and look for any abnormal winging suggestive of muscle weakness.

Scapular Retraction and Protraction

The Rhomboids are the primary retractors and the trapezius is the secondary retractor.

Stand behind the patient and instruct him/her to throw both his/her shoulder to the back into position of attention. Protraction of the scapula is enabled by the Serratus anterior muscle.

Stand behind the patient and ask him/her to flex the shoulder to 90° and flex the elbow so that his/ her hand touches the opposite shoulder.

Place one hand over the patient’s spine to prevent substitution by trunk rotation.

Now instruct the patient to reach further behind the opposite shoulder and look at the protraction of the scapula.

During protraction and retraction, feel for any crepitus suggestive of snapping scapula syndrome by keeping a hand over the scapular body.

Scapular Plane

The scapular plane is generally defined as a position of neutral scapulohumeral angulation which optimizes glenohumeral joint congruity and facilitates accurate and consistent evaluation of the joint.

This position of neutral scapulohumeral angulation is determined by the angle between a line drawn along the center axis of the scapula and second line drawn at the same level that is perpendicular to the coronal plane.

This position, which most often occurs between 20° and 30° of forward angulation relative to the coronal plane with the humerus in various degrees of abduction, minimizes the potential for acromiohumeral contact while also allowing for the theoretical isolation of the rotator cuff musculature during various clinical examination tests.

In other words, some have theorized that abduction of the humerus within the scapular plane requires zero contribution from internal or external rotators to achieve full abduction capacity.

Maximum capsuloligamentous laxity also occurs within the scapular plane (at the glenohumeral resting position, discussed below) which facilitates examination of these structures.

Although the scapular plane is generally defined as 20–30° of humeral forward angulation relative to the coronal plane in normal individuals, it must be recognized that patients with scapular malposition or dyskinesis, as which occurs commonly in overhead athletes, may have a scapular plane that differs from the rest of the population.

For example, a throwing athlete with scapular malposition may display increased protraction and upward rotation in the resting position (discussed below), thus altering the position of the glenoid such that the plane of the scapula occurs with greater forward angulation of the humerus.

Therefore, performing physical examination tests within the “normal” scapular plane in a patient with scapular malposition may produce inaccurate results.

See Also: Scapular Dyskinesis

Glenohumeral Resting Position

Also known as the “loose pack position,” the resting position of a joint is the position at which surrounding soft tissues are under the least amount of tension, the joint capsule has its greatest laxity and the bony surfaces of the joint are minimally congruent.

In other words, this position is considered to allow maximal glenohumeral mobility owing to an increase in joint laxity.

The glenohumeral resting position in normal shoulders is thought to be between 55° and 70° of abduction with the humerus in neutral rotation within the plane of the scapula.

In this position, the amount of external force required to translate the humeral head is minimal which is thought to facilitate examination accuracy. Although there is a general consensus regarding the location of the glenohumeral resting position, validation studies have seldom been conducted.

Codman Paradox

Codman’s paradox is the observation that as the arm is flexed upward in the sagittal plane and let down in the coronal plane, the humerus appears to rotate 180° as evidenced by the orientation of the palm.

In other words, when beginning the motion, the palm faces posteriorly and, at the end of the motion, the palm faces anteriorly.

Alternatively, an individual can place their hand at the top of the head through either (1) forward flexion and internal rotation or (2) abduction and external rotation.

This observation has traditionally been of academic interest; however, many investigators have attempted to mathematically solve the “paradox” using complex equations and algorithms.

Although the clinical relevance of Codman’s paradox is debatable, some authors have investigated an application of Codman’s paradox during manipulation of a stiff shoulder under anesthesia.

In addition, the quadrant test is based on Codman’s paradox and can be a useful measure of global shoulder ROM.

Force Couples About the Shoulder

An understanding of the force couples acting on the shoulder complex and the necessity of balancing the muscle strength and endurance of these muscles is especially important when the shoulder is being assessed.

Force couples are groups of counteracting muscles that show obvious action when a movement is loaded or done quickly. With a particular movement, one group of muscles (the agonists) acts concentrically or as “movers,” whereas the other group (the antagonists) acts eccentrically and as dynamic stabilizers in a controlled, harmonized fashion to produce smooth movement. Thus these muscles may work by co-contraction or co-activation to provide a stabilizing effect and joint control.

Movement	Agonist/Stabilizer	Antagonist/Stabilizer
Protraction (scapula)	Serratus anterior Pectoralis major and minor	Trapezius Rhomboids
Retraction (scapula)	Trapezius Rhomboids	Serratus anterior Pectoralis major and minor
Elevation (scapula)	Upper trapezius Levator scapulae	Serratus anterior Lower trapezius
Depression (scapula)	Serratus anterior Lower trapezius	Upper trapezius Levator scapulae
Lateral rotation (upward rotation of inferior angle of scapula)	Trapezius (upper and lower fibers) Serratus anterior	Levator scapulaeb Rhomboids Pectoralis minor
Medial rotation (downward rotation of inferior angle of scapula)	Levator scapulae Rhomboids Pectoralis minor	Trapezius (upper and lower fibers) Serratus anterior
Scapular stabilization	Upper trapezius Lower trapeziusa Rhomboids	Serratus anterior
Abduction (humerus)	Deltoid	Supraspinatus
Medial rotation (humerus)	Subscapularis Pectoralis major Latissimus dorsi Anterior deltoid Teres major	Infraspinatus Teres minor Posterior deltoid
Lateral rotation (humerus)	Infraspinatus Teres minor Posterior deltoid	Subscapularis Pectoralis major Latissimus dorsi Anterior deltoid

Question & Answers

References

1. Brunnstrom S. Muscle testing around the shoulder girdle-a study of the function of shoulder blade fixators in 17 cases of shoulder paralysis. J Bone Joint Surg Am. 1941;23:263–72.
2. Andrews JR, Gillogly S. Physical examination of the shoulder in throwing athletes. In: Zarins B, Andrews JR, Carson WG, editors. Injuries to the throwing arm. Philadelphia: W. B. Saunders; 1985.
3. Gill TK, Shanahan EM, Tucker GR, Buchbinder R, Hill CL. Shoulder range of movement in the general population: age and gender stratified normative data using a community-based cohort. BMC Musculoskelet Disord. 2020 Oct 12;21(1):676. doi: 10.1186/s12891-020-03665-9. PMID: 33046038; PMCID: PMC7549223.
4. Matsen FA 3rd, Lippitt SB, Sidles JA, Harryman DT II (eds) Practical evaluation and management of the shoulder. W.B. Saunders Company, Philadelphia, 1994.
5. Politti JC, Goroso G, Valentinuzzi ME, Bravo O. Codman’s paradox of the arm rotations is not a paradox: mathematical validation. Med Eng Phys. 1998;20(4):257–60.