Human Shoulder Joint Model, Functional

Quick Answer: The Human Shoulder Joint Model, Functional is a functional shoulder joint model with the humerus linked to the scapula so the arm can be moved through its range, showing flexion, extension, abduction, adduction and rotation at the glenohumeral joint.

Demonstrating Shoulder Movement

The shoulder moves in more directions than any other joint, and a functional model lets a class see each one. Flexion raises the arm forward and extension takes it back; abduction lifts it out to the side and adduction brings it down; medial and lateral rotation turn the humerus about its long axis, as in reaching behind the back or combing the hair; and circumduction combines them in a cone of movement.

In the living body, raising the arm overhead is shared between two sites: the glenohumeral joint and the scapula gliding and rotating on the chest wall. Over the full arc, roughly two degrees of glenohumeral movement occur for every one degree of scapular rotation, a pattern called scapulohumeral rhythm. A joint model reproduces mainly the glenohumeral part, so tutors use it to show why a stiff joint forces the shoulder blade to hitch upward, and why the humerus must rotate outward for the greater tubercle to clear the acromion.

Functional models are usually linked with flexible ligaments or cords; the title does not state the linkage, the range of movement or whether the rotator cuff is shown, so confirm them. The static shoulder joint model suits detailed study of surfaces, and the functional elbow joint model continues the arm’s movements further down.

Applications

• Physiotherapy teaching of shoulder range of motion and joint mobilisation
• Sports-science lessons on throwing, swimming and other overhead movements
• Explaining post-operative shoulder exercises to patients
• Demonstrating why impingement occurs at certain angles of arm elevation

Specifications

Care & Handling

• Move the functional shoulder joint model through its range slowly and stop at resistance; forcing it past the end of range stretches the linking cords.
• Return the arm to the side after each demonstration rather than leaving it raised overhead.
• Inspect the linkage regularly and set the model aside if the humeral head starts slipping from the socket.

Why Choose LabEquip

Physiotherapy colleges and sports-rehabilitation units choose a movable shoulder so trainees can see a movement before they assess it on a patient. LabEquip lists this model under biology lab products; send questions about its linkage through the contact page.

Frequently Asked Questions

What is scapulohumeral rhythm?

The coordinated movement of the humerus and the scapula when the arm is raised. Over the full arc, about two parts of movement happen at the glenohumeral joint for every one part of scapular rotation on the chest wall.

Why must the arm rotate outward to be raised fully overhead?

Lateral rotation turns the greater tubercle of the humerus back so it passes behind the acromion instead of striking it. Without it, elevation is blocked and tissues beneath the acromion are pinched.

What is the painful arc?

Pain felt in the middle range of raising the arm sideways, roughly between sixty and one hundred and twenty degrees, which eases above and below it. It is a typical sign of subacromial impingement.

Which muscle starts abduction of the arm?

The supraspinatus helps start the movement and keeps the humeral head centred, then the deltoid becomes the main abductor. With a weak rotator cuff, the deltoid tends to pull the head upward instead.

How is the functional model different from the static shoulder model?

The functional model links the humerus to the scapula so the arm can be moved through its range. The static model holds the bones in one position for studying surfaces and landmarks.

Can the model show dislocation?

It can be used to explain the direction of an anterior dislocation, but it should not be forced out of the socket. Repeated forcing damages the linkage and the model’s surfaces.

Last Updated: September 2026