Syllabus coverage
- Identify the types of synovial joint and the articulating bones at the shoulder, elbow, wrist, radioulnar, hip, knee and ankle joints
- Compare and explain the stability and range of movement of these joints
- Identify and describe the types of movement that can occur at the named joints and the main agonist muscle for each movement
Part of the AS Level PE 8386 syllabus 8386.
The seven joints Cambridge names
Cambridge gives you a fixed table of seven joints, each with its type of synovial joint and the bones that articulate (meet) there. Learn it as a table rather than as prose, because almost every question in this subtopic starts from it.
The articulating bones are the bone surfaces that meet at the joint. Cambridge names only those bones, so only those bones belong in your answer.
| Joint | Type of synovial joint | Articulating bones |
|---|---|---|
| Shoulder | Ball and socket | Humerus and scapula |
| Elbow | Hinge | Humerus, radius and ulna |
| Wrist | Condyloid | Radius and carpals |
| Radioulnar | Pivot | Radius and ulna |
| Hip | Ball and socket | Femur and pelvis |
| Knee | Hinge | Femur and tibia |
| Ankle | Hinge | Tibia, fibula and talus |
What is inside a synovial joint, and why it decides stability
Every joint in the table above is a synovial joint, which means the bone ends are separated by a cavity and the joint is built for movement.
Articular cartilage covers the ends of the bones, reducing friction and absorbing shock. The synovial membrane lines the joint capsule and secretes synovial fluid, which lubricates the joint and nourishes the cartilage. The joint capsule and the ligaments around it hold the bones together and limit how far the joint can move.
Those last two features are the ones that decide stability. The closer the fit between the bone surfaces and the stronger the ligaments, the more stable the joint is and the smaller its range of movement.
- Articular cartilage: reduces friction and absorbs shock at the bone ends
- Synovial fluid: lubricates the joint so movement is smooth and friction-free
- Joint capsule and ligaments: hold the bones together and restrict excessive movement
- Bone fit: a deep socket or a tight hinge is more stable than a shallow socket
The movements at each joint and the main agonist
This is the heart of the subtopic. Cambridge lists each movement with the main agonist — the muscle that contracts to produce that movement.
Learn it joint by joint. If you can recall one joint's row without hesitation, the rest follows the same pattern.
| Joint | Types of movement and main agonist |
|---|---|
| Shoulder | Flexion — anterior deltoid. Extension — posterior deltoid. Abduction — medial deltoid. Adduction — latissimus dorsi. Horizontal flexion — pectoralis major. Horizontal extension — posterior deltoid |
| Elbow | Flexion — biceps brachii. Extension — triceps brachii |
| Wrist | Flexion — wrist flexors. Extension — wrist extensors |
| Radioulnar | Pronation — pronator teres. Supination — supinator |
| Hip | Flexion — iliopsoas. Extension — gluteus maximus. Abduction — gluteus medius. Adduction — adductor longus |
| Knee | Flexion — biceps femoris. Extension — rectus femoris |
| Ankle | Dorsiflexion — tibialis anterior. Plantar flexion — gastrocnemius |
Stability and range of movement: how to compare any two joints
Range of movement is how far the joint can move and in how many planes (directions). Stability is how well the joint resists dislocation under load.
These work against each other. A joint built for a large range of movement is built with a shallower socket and looser ligaments, so it is less stable. A joint built for stability fits tightly and moves in fewer planes.
Compare the two ball and socket joints to see the rule. The shoulder socket in the scapula is shallow, so the humerus can swing through flexion, extension, abduction, adduction and rotation — the greatest range of any joint, and the joint that dislocates most easily. The hip is also ball and socket, but the femur head sits in a deep socket in the pelvis with strong ligaments, so it is far more stable and has a smaller range of movement.
Now compare the two-plane and one-plane joints. The wrist is condyloid, so it moves in two planes (flexion and extension, and side to side) and is moderately stable. The radioulnar joint is a pivot, so it only rotates and is very stable with almost no range beyond rotation. The hinge joints — elbow, knee and ankle — move in one plane only, which makes them stable and strong but limits them to one direction of travel.
| Joint | Stability | Range of movement | Reason |
|---|---|---|---|
| Shoulder | Low | Greatest of all joints | Shallow socket in the scapula and loose ligaments allow movement in all planes |
| Hip | High | Large but smaller than the shoulder | Deep socket in the pelvis, strong ligaments and a large bone fitting |
| Elbow | High | One plane only | Hinge joint with tight ligaments; limited to flexion and extension |
| Knee | High | One plane only | Hinge joint with strong ligaments; carries body weight so must resist dislocation |
| Ankle | High | One plane only | Hinge joint bearing the whole body weight, with the talus held between tibia and fibula |
| Wrist | Moderate | Two planes | Condyloid joint between the radius and the carpals |
| Radioulnar | Very high | Rotation only | Pivot joint; the radius rotates around the ulna |
Using the correct word for the movement
Half the marks lost in this subtopic are lost by using the wrong term, so be precise.
Flexion decreases the angle at a joint; extension increases it. Abduction moves the limb away from the midline of the body; adduction moves it back towards the midline.
Horizontal flexion and horizontal extension happen at the shoulder when the arm is already raised to shoulder height: horizontal flexion swings it forwards across the body, horizontal extension swings it backwards. Pronation turns the forearm so the palm faces down; supination turns it so the palm faces up. Dorsiflexion at the ankle pulls the toes up towards the shin; plantar flexion pushes the toes down, as in a jump take-off.
Turning joint knowledge into marks
A one-mark question wants one fact: "Hinge" or "Ball and socket". Nothing more is needed.
An explain question wants a chain. Build it in this order: name the joint, name its type, name the articulating bones, name the movement, name the agonist, then say what that movement achieves for the performer.
An analyse question wants several of those chains joined together. Work through the joints in the order the movement happens — hip, then knee, then ankle for a kick, for example.
- State: the fact only
- Describe: the fact plus what it means in the body
- Explain: the fact plus a consequence for the performer
- Analyse: several linked chains across more than one joint
Key terms you must be able to define
- Synovial joint
- A freely movable joint in which the bone ends are separated by a joint cavity containing synovial fluid.
- Ball and socket joint
- A synovial joint in which a rounded bone head fits into a cup-shaped socket, allowing movement in all planes (shoulder, hip).
- Hinge joint
- A synovial joint that allows movement in one plane only, flexion and extension (elbow, knee, ankle).
- Condyloid joint
- A synovial joint in which an oval bone end fits into a shallow cavity, allowing movement in two planes (wrist).
- Pivot joint
- A synovial joint that allows rotation only, where one bone rotates around another (radioulnar).
- Articulating bones
- The bones whose surfaces meet at a joint.
- Flexion
- Movement that decreases the angle at a joint.
- Extension
- Movement that increases the angle at a joint.
- Abduction
- Movement of a limb away from the midline of the body.
- Adduction
- Movement of a limb towards the midline of the body.
- Horizontal flexion
- Movement of the arm forwards across the body at shoulder height.
- Horizontal extension
- Movement of the arm backwards at shoulder height.
- Pronation
- Rotation of the radioulnar joint so that the palm faces downwards.
- Supination
- Rotation of the radioulnar joint so that the palm faces upwards.
- Dorsiflexion
- Movement at the ankle that lifts the toes towards the shin.
- Plantar flexion
- Movement at the ankle that points the toes downwards.
- Range of movement
- How far a joint can move and the number of planes in which it can move.
- Stability
- The ability of a joint to resist dislocation when it is loaded.
Applied to your sport
Cambridge requires you to apply this knowledge to physical activities. Use these as models, then write your own for the sport you play.
An overhead smash needs the shoulder's ball and socket structure: horizontal flexion of the pectoralis major drives the arm through the shuttle, while the elbow hinge extends through the triceps brachii.
Kicking for goal at the knee joint: the hinge between femur and tibia makes the knee very stable under load, and rectus femoris extends it to strike the ball.
The condyloid wrist joint allows the wrist flexors to snap the hand downwards at the release of a jump shot, putting backspin on the ball.
At the start of a sprint the hip extends via gluteus maximus, the knee extends via rectus femoris and the ankle plantar flexes via gastrocnemius, all in the same movement.
The radioulnar pivot joint lets the pronator teres and supinator roll the forearm over, changing the angle of the bat face for a forehand or backhand drive.
Flashcards
Click a card to flip it. Mark honestly — the tracker uses this.
Exam-style questions
7 questions, 19 marks. Write your answer, then reveal the mark scheme and tick each point you actually made. Answering honestly here is what makes the rest of the site useful.
Mark scheme — tick each point you actually made
Mark scheme — tick each point you actually made
Mark scheme — tick each point you actually made
Mark scheme — tick each point you actually made
Mark scheme — tick each point you actually made
Mark scheme — tick each point you actually made
Mark scheme — tick each point you actually made
Exam technique for this topic
- Learn the joint table in the order Cambridge gives it (shoulder, elbow, wrist, radioulnar, hip, knee, ankle) so you can recall a row without working through the whole list.
- If a question says "types of movement", list the movements and the agonist that produces each one — an answer with a movement but no muscle is capped at half marks.
- For comparison questions, always give both joints and a reason for each. "The hip is more stable" scores nothing on its own; "it is more stable because the femur sits in a deep socket in the pelvis" scores.
- Use anatomical terms, not everyday language. "The shoulder rotates" is not a mark when the movement is abduction.
- Only use physical activities from the 8386 Component 2 list — for example Association football, Badminton, Basketball, Competitive swimming, Cricket, Cross-country running, Field hockey, Goalball, Netball, Olympic weightlifting, Rugby union, Squash, Table tennis, Tennis, Track and field athletics or Volleyball.