Applying the Musculoskeletal System to Sport

This lesson is an integration lesson that brings together everything you have learned about the musculoskeletal system and applies it to specific sporting actions. The AQA GCSE PE specification (3.1.1.1) requires you to analyse movements by identifying the bones, joints, muscles, movements, and types of contraction involved. This is the skill that earns the highest marks in the exam.

Being able to break down a sporting action into its component parts — identifying which muscles are working, what type of contraction they are performing, which joints are involved, and what movements are occurring — is the ultimate test of your understanding of this topic.

---

The Analysis Framework

When analysing any sporting action, use this systematic approach:

flowchart TD
    A["Sporting Action"] --> B["1. Identify the joints involved"]
    B --> C["2. Identify the type of joint"]
    C --> D["3. Identify the movement at each joint"]
    D --> E["4. Identify the agonist and antagonist"]
    E --> F["5. Identify the type of contraction"]

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

For each joint involved in the action, you should be able to state:

1. The joint (e.g., knee)
2. The type of joint (e.g., hinge)
3. The movement occurring (e.g., extension)
4. The agonist (e.g., quadriceps)
5. The antagonist (e.g., hamstrings)
6. The type of contraction of the agonist (e.g., concentric)

Exam Tip: Extended-answer questions (6 marks) on this topic require you to analyse at least two or three joints in detail. A common question format is: "Analyse the musculoskeletal actions involved in [specific sporting movement]." To gain full marks, you must cover multiple joints and include all the elements listed above.

---

Analysis 1: Kicking a Football

Kicking a football involves movement at the hip, knee, and ankle. We can break the kicking action into two phases: the preparation (backswing) and the execution (the kick itself).

Preparation Phase (Drawing the Leg Back)

Joint	Type	Movement	Agonist	Antagonist	Contraction
Hip	Ball and socket	Extension	Gluteals	Hip flexors	Concentric
Knee	Hinge	Flexion	Hamstrings	Quadriceps	Concentric

Execution Phase (Kicking Through the Ball)

Joint	Type	Movement	Agonist	Antagonist	Contraction
Hip	Ball and socket	Flexion	Hip flexors	Gluteals	Concentric
Knee	Hinge	Extension	Quadriceps	Hamstrings	Concentric
Ankle	Hinge	Plantarflexion	Gastrocnemius	Tibialis anterior	Concentric

Key Points

• During the preparation phase, the leg swings backward — extension at the hip and flexion at the knee create the "wind-up" that generates power.
• During the execution phase, the leg swings forward explosively — flexion at the hip and extension at the knee drive the foot into the ball.
• Plantarflexion at the ankle keeps the foot firm at the point of contact.
• The quadriceps is the primary muscle responsible for the power of the kick (extension at the knee).
• The hip flexors bring the whole leg forward, while the gluteals were responsible for taking it back.

---

Analysis 2: Performing a Press-Up

A press-up involves movement at the elbow and shoulder. There are two phases: the lowering phase (going down) and the pushing phase (coming up).

Lowering Phase (Going Down)

Joint	Type	Movement	Agonist	Contraction Type
Elbow	Hinge	Flexion	Triceps	Eccentric (triceps lengthens to control the descent)
Shoulder	Ball and socket	Extension (horizontal)	Pectorals	Eccentric (pectorals lengthen to control the descent)

Pushing Phase (Coming Up)

Joint	Type	Movement	Agonist	Contraction Type
Elbow	Hinge	Extension	Triceps	Concentric (triceps shortens to push up)
Shoulder	Ball and socket	Flexion (horizontal)	Pectorals	Concentric (pectorals shorten to push up)

Key Points

• The press-up is an excellent example of eccentric and concentric contractions in the same exercise.
• Going down = eccentric (muscles lengthen under tension to control the descent against gravity).
• Pushing up = concentric (muscles shorten to produce the upward force).
• The abdominals work isometrically throughout both phases to keep the body straight — without isometric abdominal contraction, the hips would sag.

---

Analysis 3: Sprinting (One Stride)

Sprinting involves complex movements at the hip, knee, and ankle. Here we analyse the drive phase (pushing off the ground) of one stride.

Drive Phase

Joint	Type	Movement	Agonist	Antagonist	Contraction
Hip	Ball and socket	Extension	Gluteals	Hip flexors	Concentric
Knee	Hinge	Extension	Quadriceps	Hamstrings	Concentric
Ankle	Hinge	Plantarflexion	Gastrocnemius	Tibialis anterior	Concentric

Recovery Phase (Swinging the Leg Forward)

Joint	Type	Movement	Agonist	Antagonist	Contraction
Hip	Ball and socket	Flexion	Hip flexors	Gluteals	Concentric
Knee	Hinge	Flexion	Hamstrings	Quadriceps	Concentric
Ankle	Hinge	Dorsiflexion	Tibialis anterior	Gastrocnemius	Concentric

Key Points

• Sprinting requires powerful extension at the hip, knee, and ankle during the drive phase — this is where speed is generated.
• The gluteals, quadriceps, and gastrocnemius are the key muscles producing the driving force.
• During the recovery phase, the hip flexors lift the knee, the hamstrings flex the knee to bring the heel towards the buttock, and the tibialis anterior dorsiflexes the ankle to clear the foot from the ground.
• The core muscles (abdominals) work isometrically throughout to stabilise the trunk and transfer force efficiently between the upper and lower body.

---

Analysis 4: A Bicep Curl

The bicep curl is the simplest example to analyse and is commonly used in exam questions.

Phase	Joint	Type	Movement	Agonist	Antagonist	Contraction
Upward (lifting)	Elbow	Hinge	Flexion	Biceps	Triceps	Concentric
Holding at the top	Elbow	Hinge	No movement	Biceps	Triceps	Isometric
Downward (lowering)	Elbow	Hinge	Extension	Biceps	Triceps	Eccentric

Key Points