Answers to ‘Revise as you go’
1. The shoulder, elbow, hip, knee and ankle joints, are all synovial joints:
i. identify the bones that articulate at each of these joints
ii. identify the type of synovial joint located at each of these joints
Synovial Joint
i. Articulating Bones
ii. Type of Synovial Joint
Shoulder
Ball and socket
Elbow
Hip
Scapula (glenoid fossa) and humerus
(head)
Humerus, radius and ulna
Pelvis (acetabulum) and Femur (head)
Knee
Ankle
Femur and tibia
Tibia, fibula and talus
Hinge
Hinge
Hinge
Ball and socket
2. The spine has a number of different types of joint located in its different regions. Explain this
statement giving specific examples.
A pivot joint found between the atlas and axis in the cervical region of the spine.
Gliding joints found between the adjacent bony processes of the vertebra in the cervical, thoracic and
lumbar regions.
Cartilaginous joints found between the bodies of adjacent vertebrae in the cervical, thoracic and lumbar
regions.
3. Identify the movement performed at each of the joints listed in brackets from the sporting
techniques stated below:
i. upward phase of a sit up (spine and hip)
ii. downward phase of a press up (shoulder and elbow)
iii. preparation phase of a vertical jump (hip, knee, ankle)
iv. execution phase of a top-spin forehand in tennis (shoulder, elbow, radio-ulnar)
Joint
Movement
i. Upward phase of sit up
Spine
Flexion
Hip
Flexion
ii. Downward phase of press up
Shoulder
Horizontal extension
Elbow
Flexion
iii. Preparation phase of vertical jump
Hip
Flexion
Knee
Flexion
Ankle
Dorsiflexion
iv. Execution phase of top spin forehand in tennis
Shoulder
(Horizontal) flexion
Elbow
Flexion
Radio-ulnar
Pronation
4. Identify the agonist and antagonist muscles for each of the movements you have identified in
your answer to question 3.
Joint
Movement
i. Upward phase of sit up
Spine
Flexion
Agonist
Antagonist
Rectus Abdominis
Hip
Flexion
ii. Downward phase of press up
Shoulder
Horizontal
extension
Elbow
Flexion
iii. Preparation phase of vertical jump
Hip
Flexion
Knee
Flexion
Iliopsoas
Erector spinae
group
Gluteus maximus
Pectoralis major
Trapezius
Biceps brachii
Triceps brachii
Iliopsoas
(Hamstrings)
Biceps femoris
Semimembranosus
Semitendinosus
Gluteus maximus
(Quadriceps)
Rectus femoris
Vastus lateralis
Vastus medialis
Vastus intermedius
Gastrocnemius
Ankle
Dorsiflexion
Tibilais anterior
iv. Execution phase of top spin forehand in tennis
Shoulder
Horizontal
Pectoralis
flexion/flexion
major/anterior
deltoid
Elbow
Flexion
Biceps brachii
Radio-ulnar
Pronation
Pronator teres
Trapezius/posterior
deltoid
Triceps brachii
Supinator
5. Identify, explain and give sporting examples of concentric, eccentric and isometric muscular
contraction.
Concentric muscular contraction
A form of isotonic muscular contraction.
Tension is produced in the muscle while it shortens.
It causes joint movement.
It occurs in the agonist muscle during movement, e.g., in the muscles of the quadriceps as extension of
the knee occurs when kicking a football.
Eccentric muscular contraction
A form of isotonic muscular contraction.
Tension is produced in the muscle while it lengthens.
It controls joint movement, e.g., in the rectus abdominis during the downward phase of a sit up.
Isometric muscular contraction
Tension is produced in the muscle while it remains the same length.
No joint movement occurs.
It stops joint movement, e.g., in the biceps brachii and triceps brachii muscles when a gymnast is holding
a handstand position.
6. What are the three types of muscle fibre found in skeletal muscle? Identify two structural and
two functional differences in their characteristics.
Slow twitch/type 1
Fast oxidative glycolytic/type 2a
Fast glycolytic/type 2b
Structural Differences (2 from)
small
Fast Oxidative
Glycolytic
(Type 2a/FOG)
large
large
moderate
small
large
moderate
small
high
low
low
moderate
high
high
low
high
high
high
moderate
low
slow
fast
fastest
low
high
highest
high
low
lowest
high
low
lowest
low
high
highest
Slow Twitch
(Type 1)
Fibre size
Number of
mitochondria
Number of
capillaries
Myoglobin content
PC stores
Glycogen stores
Triglyceride
stores
Fast Glycolytic
(Type 2b/FG)
large
Functional Differences (2 from)
Speed of
contraction
Force of
contraction
Resistance to
fatigue
Aerobic capacity
Anaerobic
capacity
7. Explain why elite marathon runners have a high percentage of slow twitch muscles in their
gastrocnemius muscle.
Slow twitch muscle fibres are well suited to endurance events.
They can use oxygen efficiently due to their high number of mitochondria/high number of
capillaries/high myoglobin content.
This gives them a high aerobic capacity.
They are also resistant to fatigue because they can use fats/triglyceride stores for energy which
provide far more energy than carbohydrates.
8. Skeletal muscles work more efficiently if a performer carries out a warm up prior to the
exercise session and a cool down afterwards. Explain this statement.
A warm up will increase the quality of performance by preparing the body for exercise and reducing the
risk of injury.
It increases core body temperature, which will produce the following physiological effects on skeletal
muscle tissue:
a reduction in muscle viscosity, leading to an improvement in the efficiency of muscular
contractions;
a greater speed and force of contraction due to a higher speed of nerve transmission;
an increased flexibility that reduces the risk of injury due to increased extensibility of tendons
and ligaments.
9. Describe the positive effects of exercise on preventing osteoporosis.
Physical activity is extremely important in maintaining healthy bones.
Low impact activity in childhood and adolescence builds strong, healthy bones.
High impact activity increases peak bone density.
A high peak bone density helps to minimise the risk of osteoporosis in later life. Participation in
resistance or strength training, weight-bearing activities and high impact activities has a positive effect
on bone health and is associated with a long term reduced risk of osteoporosis.
10. Describe the potential dangers of high impact and contact sports on the musculo-skeletal
system.
If somebody is already suffering from osteoporosis, high impact activity can cause bone fractures at
the site of the weakened bone and joint.
With high impact activity and contact sports there is an increased risk of sprains, strains and
dislocations.
High impact or contact activity can cause growth plate injuries.
Exercise carried out too frequently or at too high an intensity promotes wear and tear on the joint and
promotes the start of osteoarthritis.
Exercise that causes damage to the joints can reduce joint stability as ligaments and tendons are
stretched, making the joint less stable.