smc-5521-25-Muscle relationships

HMS, BM EQ-Bank 839

Evaluate the importance of synergists and stabilisers in complex sporting movements, using specific examples to illustrate your answer. (6 marks)

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Sample Answer

Synergists work with prime movers to produce more effective force generation, as seen when the brachialis and brachioradialis assist the biceps brachii during climbing movements, enabling greater overall strength and endurance.
Stabiliser muscles maintain joint position during movement, critical in activities like gymnastics where core stabilisers prevent excessive spinal movement during dynamic skills on apparatus.
In throwing sports, rotator cuff muscles act as stabilisers for the shoulder joint, preventing potentially damaging movement of the humeral head while allowing powerful actions of prime movers like the deltoid and pectoralis major.
The effectiveness of synergists varies between individuals, contributing to differences in technique efficiency; for example, runners with stronger hip abductor synergists typically maintain better pelvic stability, reducing injury risk.
Weakness in stabiliser muscles frequently contributes to poor technique and injury, as seen when inadequate scapular stabilisers lead to shoulder impingement in swimmers.
Training programs that neglect synergists and stabilisers in favor of only prime movers often result in muscle imbalances, reducing performance and increasing injury risk, as commonly seen in recreational athletes who focus solely on visible “eye-catching” muscles.

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Sample Answer

Synergists work with prime movers to produce more effective force generation, as seen when the brachialis and brachioradialis assist the biceps brachii during climbing movements, enabling greater overall strength and endurance.
Stabiliser muscles maintain joint position during movement, critical in activities like gymnastics where core stabilisers prevent excessive spinal movement during dynamic skills on apparatus.
In throwing sports, rotator cuff muscles act as stabilisers for the shoulder joint, preventing potentially damaging movement of the humeral head while allowing powerful actions of prime movers like the deltoid and pectoralis major.
The effectiveness of synergists varies between individuals, contributing to differences in technique efficiency; for example, runners with stronger hip abductor synergists typically maintain better pelvic stability, reducing injury risk.
Weakness in stabiliser muscles frequently contributes to poor technique and injury, as seen when inadequate scapular stabilisers lead to shoulder impingement in swimmers.
Training programs that neglect synergists and stabilisers in favor of only prime movers often result in muscle imbalances, reducing performance and increasing injury risk, as commonly seen in recreational athletes who focus solely on visible “eye-catching” muscles.

HMS, BM EQ-Bank 838

Analyse how the agonist/antagonist relationship facilitates efficient movement in sporting activities. (5 marks)

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Sample Answer

The agonist/antagonist relationship creates smooth movement because when one muscle contracts (the agonist), the opposite muscle relaxes (the antagonist). This prevents the muscles from fighting against each other, allowing efficient movement to occur.
This relationship allows for precise control of both the speed and force of movements, as seen in a tennis player adjusting their stroke based on the game situation.
During rapid movements like sprinting, the proper sequencing of agonist contraction and antagonist relaxation maximises power output and movement efficiency.
The relationship protects joints from injury by providing balanced muscle development and preventing excessive movement beyond a joint’s normal range of motion.
In skilled movements requiring fine motor control, such as archery, the precise coordination between agonists and antagonists enables the stability and accuracy needed for consistent performance.

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Sample Answer

The agonist/antagonist relationship creates smooth movement because when one muscle contracts (the agonist), the opposite muscle relaxes (the antagonist). This prevents the muscles from fighting against each other, allowing efficient movement to occur.
This relationship allows for precise control of both the speed and force of movements, as seen in a tennis player adjusting their stroke based on the game situation.
During rapid movements like sprinting, the proper sequencing of agonist contraction and antagonist relaxation maximises power output and movement efficiency.
The relationship protects joints from injury by providing balanced muscle development and preventing excessive movement beyond a joint’s normal range of motion.
In skilled movements requiring fine motor control, such as archery, the precise coordination between agonists and antagonists enables the stability and accuracy needed for consistent performance.

HMS, BM EQ-Bank 837

Explain the role of agonist, antagonist, and stabiliser muscles during a push-up exercise. (4 marks)

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Sample Answer

During the lowering phase of a push-up, the pectoralis major and triceps brachii act as antagonists, lengthening under tension to control the descent.
In the pushing (upward) phase, these same muscles become the agonists, contracting concentrically to extend the elbows and push the body away from the ground.
The biceps brachii function as antagonists during the pushing phase, relaxing to allow full extension of the elbow.
Core muscles including the rectus abdominis, transverse abdominis, and erector spinae act as stabilisers throughout the movement, maintaining proper body alignment and preventing sagging of the hips or lower back.

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Sample Answer

During the lowering phase of a push-up, the pectoralis major and triceps brachii act as antagonists, lengthening under tension to control the descent.
In the pushing (upward) phase, these same muscles become the agonists, contracting concentrically to extend the elbows and push the body away from the ground.
The biceps brachii function as antagonists during the pushing phase, relaxing to allow full extension of the elbow.
Core muscles including the rectus abdominis, transverse abdominis, and erector spinae act as stabilisers throughout the movement, maintaining proper body alignment and preventing sagging of the hips or lower back.

HMS, BM EQ-Bank 836 MC

When performing a squat, which muscle acts as a stabiliser for the knee joint?

Rectus femoris
Biceps femoris
Vastus medialis
Gluteus maximus

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\(C\)

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Consider Option C:

The vastus medialis, part of the quadriceps group, plays a crucial role in stabilising the knee joint, particularly the patella, during squatting movements.

Other Options:

A is incorrect: While the rectus femoris is part of the quadriceps group, its primary role is as an agonist for knee extension and hip flexion, not specifically as a knee stabiliser.
B is incorrect: The biceps femoris is part of the hamstring group and acts as an antagonist to knee extension during a squat, not as a stabiliser.
D is incorrect: The gluteus maximus primarily extends the hip during a squat and doesn’t directly stabilise the knee joint.

\(\Rightarrow C\)

HMS, BM EQ-Bank 835 MC

In a bicep curl, which muscle pair represents the agonist and antagonist relationship?

Biceps brachii and brachialis
Biceps brachii and triceps brachii
Triceps brachii and deltoid
Deltoid and pectoralis major

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\(B\)

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Consider Option B:

The biceps brachii (agonist) contracts to flex the elbow during a bicep curl
The triceps brachii (antagonist) relaxes to allow the movement and contracts to perform the opposite movement (extension).

Other Options:

A is incorrect: Both biceps brachii and brachialis are synergists that work together to flex the elbow, not an agonist-antagonist pair.
C is incorrect: Triceps and deltoid are not direct antagonists; they work on different joints and movements.
D is incorrect: Deltoid and pectoralis major are not direct antagonists; they can both act on the shoulder but in different movement patterns.

\(\Rightarrow B\)

HMS, BM EQ-Bank 44

Describe TWO ways muscle pairs work together to produce safe movement. (3 marks)

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Sample Answer

Agonist/antagonist relationship controls movement speed
Co-contraction provides joint stability
Balanced strength prevents muscle imbalances
Coordinated action produces smooth movement

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Sample Answer

Agonist/antagonist relationship controls movement speed
Co-contraction provides joint stability
Balanced strength prevents muscle imbalances
Coordinated action produces smooth movement

HMS, BM EQ-Bank 37

Describe TWO characteristics and functions of fast twitch muscle fibres. (3 marks)

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Sample Answer

Fast twitch fibres have fewer mitochondria compared to slow twitch fibres
They rely primarily on anaerobic glycolysis for energy production
They are capable of producing greater force in a shorter time period
They fatigue more quickly than slow twitch fibres due to their energy system reliance

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Sample Answer

Fast twitch fibres have fewer mitochondria compared to slow twitch fibres
They rely primarily on anaerobic glycolysis for energy production
They are capable of producing greater force in a shorter time period
They fatigue more quickly than slow twitch fibres due to their energy system reliance

HMS, BM EQ-Bank 27 MC

Which pair of muscles work together in an agonist-antagonist relationship?

Deltoid and trapezius
Biceps and gastrocnemius
Triceps and biceps brachii
Quadriceps and deltoid

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\(C\)

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Consider Option C:

These muscles work in direct opposition at the elbow joint – biceps flexes while triceps extends

Other Options:

A: Incorrect because deltoid and trapezius work in different regions and don’t form an antagonistic pair
B: Incorrect because biceps and gastrocnemius work at different joints (elbow and ankle respectively)
D: Incorrect because quadriceps and deltoid work at different joints (knee and shoulder respectively)

\(\Rightarrow C\)

HMS, BM EQ-Bank 23 MC

During a biceps curl, what occurs at the elbow joint?

The biceps contracts concentrically as the primary agonist
The triceps contracts concentrically as the primary agonist
The biceps and triceps contract simultaneously
The triceps relaxes while the biceps stabilises

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\(A\)

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Consider Option A:

During the lifting phase of a biceps curl, the biceps muscle shortens (contracts concentrically) while generating force to lift the weight
The biceps is the primary agonist (prime mover) in elbow flexion
As the agonist, it is responsible for producing the desired movement against gravity
The triceps (antagonist) relaxes during this phase through reciprocal inhibition.

The other options are incorrect because:
B: The triceps extends the elbow – it is not the agonist during a curl
C: The biceps and triceps don’t contract simultaneously due to reciprocal inhibition
D: This reverses the roles – the triceps relaxes but the biceps contracts rather than stabilises

\(\Rightarrow A\)