Tendons and Ligaments

This lesson covers tendons and ligaments in detail as required by the OCR GCSE PE specification (J587). You need to understand the difference between these two types of connective tissue, know their structure and function, be able to explain their roles in movement and joint stability, and apply this knowledge to sporting examples and injuries.

---

Overview: Tendons vs Ligaments

Tendons and ligaments are both types of connective tissue found at joints, but they have different structures and functions. Being able to distinguish between them is one of the most frequently tested concepts in GCSE PE.

Feature	Tendons	Ligaments
What they connect	Muscle to bone	Bone to bone
Function	Transmit force from muscle to bone, producing movement	Stabilise joints and prevent excessive movement
Elasticity	Relatively inelastic (do not stretch much)	Slightly elastic (allow some give)
Colour	White (poor blood supply)	White/yellowish
Key example	Achilles tendon	Anterior cruciate ligament (ACL)

graph TD
    A["Connective Tissue at Joints"] --> B["Tendons"]
    A --> C["Ligaments"]
    B --> D["Connect muscle to bone"]
    B --> E["Transmit force for movement"]
    C --> F["Connect bone to bone"]
    C --> G["Stabilise the joint"]

    style A fill:#4a90d9,color:#fff
    style B fill:#e67e22,color:#fff
    style C fill:#27ae60,color:#fff

Exam Tip: The simplest way to remember the difference: Tendons connect muscle To bone (T for tendon, T for "to"). Ligaments connect bone to bone and provide stabiLity (L for ligament, L for stability link).

---

Tendons in Detail

Structure and Function

A tendon is a tough, fibrous cord of connective tissue that attaches the end of a muscle to a bone. Tendons are made primarily of collagen fibres, which are arranged in parallel bundles, giving them great tensile strength (resistance to being pulled apart).

Key properties of tendons:

• Strong — tendons must withstand the large forces generated when muscles contract.
• Relatively inelastic — tendons do not stretch significantly. This is essential because any stretching would mean that the force from the muscle contraction would be "lost" in the tendon rather than being transmitted to the bone.
• Poor blood supply — tendons have a limited blood supply, which means they heal slowly when injured.

How Tendons Work in Movement

1. A muscle contracts (shortens).
2. The tendon attached to the muscle transmits the force to the bone.
3. The bone moves at the joint, producing a sporting movement.

Without tendons, muscle contractions would not result in any movement of the skeleton.

flowchart LR
    A["Muscle contracts"] --> B["Force transmitted<br>through tendon"]
    B --> C["Bone moves<br>at joint"]
    C --> D["Sporting<br>movement"]

    style A fill:#27ae60,color:#fff
    style B fill:#e67e22,color:#fff
    style C fill:#4a90d9,color:#fff
    style D fill:#9b59b6,color:#fff

Key Tendons in the Body

Tendon	Connects	Sporting Relevance
Achilles tendon	Gastrocnemius (calf) to calcaneus (heel bone)	Running, jumping, sprinting — transmits force to push off the ground
Patellar tendon	Quadriceps to tibia (via the patella)	Kicking, jumping, squatting — transmits force to extend the knee
Biceps tendon	Biceps to radius	Pulling, lifting, bicep curls — transmits force to flex the elbow
Hamstring tendons	Hamstrings to tibia/fibula	Sprinting, bending the knee — transmits force to flex the knee

Tendon Injuries

• Tendinitis — inflammation of a tendon caused by overuse. Common in the Achilles tendon (runners), the patellar tendon (jumpers), and the elbow tendons (tennis/golfer's elbow). Symptoms include pain, swelling, and stiffness.
• Tendon rupture — a complete or partial tear of a tendon. The Achilles tendon is the most commonly ruptured tendon in sport, often occurring during sudden, explosive movements like sprinting or jumping.

---

Ligaments in Detail

Structure and Function

A ligament is a tough band of fibrous connective tissue that connects bone to bone across a joint. Ligaments are also made of collagen fibres but have a slightly different arrangement that gives them limited elasticity.