smooth muscle – found in the internal organs and blood vessels - this is involuntary
cardiac muscle – found only in the heart - this is involuntary
skeletal muscle – attached to the skeleton - this is voluntary
Involuntary muscles are not under our conscious control which means we can't make them contract when we think about it.
Voluntary muscles are under our conscious control so we can move these muscles when we want to. These are the muscles we use to make all the movements needed in physical activity and sport.
The main skeletal muscles of the human body are shown here.
Function
Example in sport
Deltoid
Lifting the arm at the shoulder (the deltoid muscle has different parts which flex, extend and abduct the shoulder joint)
Lifting the arms to block in volleyball; upward arm swing when trampolining
Trapezius
Shoulder horizontal extension (moving the arms backwards at shoulder level)
Preparation phase of an overarm throw or badminton smash
Pectorals
Adduction of the shoulder (moving the arm towards the body); Shoulder horizontal flexion (moving the arms forwards in front of the body)
Upwards phase of a press up; rugby player making a tackle
Triceps
Extension of the elbow (straightening the arm)
Shooting and chest passing in netball (execution phase)
Biceps
Flexion of the elbow (bending the arm)
Drawing a bow in archery; 'backscratch' position during tennis serve
Abdominals
Flexion of the spine (sitting upwards)
Performing a sit up or a forward roll
Latissimus dorsi
Adduction of the shoulder (moving the arm down towards the mid-line of the body)
Hitting in hockey – left shoulder during preparation, right shoulder during execution and recovery
Gluteals
Hip extension (moving the femur backwards)
Pulling leg back at the hip before kicking a ball
Quadriceps
Extension of the knee (straightening the leg)
Kicking a ball (execution and recovery phase)
Hamstrings
Flexion of the knee (bending the leg)
Performing a hamstring curl on a weights machine; preparation phase of a rebound jump in basketball
Gastrocnemius
Plantar flexion of the ankle (pointing the toes downwards)
Standing on tiptoe to mark a shot in netball or pointing the toes during a gymnastic or dance move
Deltoid
Function
Lifting the arm at the shoulder (the deltoid muscle has different parts which flex, extend and abduct the shoulder joint)
Example in sport
Lifting the arms to block in volleyball; upward arm swing when trampolining
Trapezius
Function
Shoulder horizontal extension (moving the arms backwards at shoulder level)
Example in sport
Preparation phase of an overarm throw or badminton smash
Pectorals
Function
Adduction of the shoulder (moving the arm towards the body); Shoulder horizontal flexion (moving the arms forwards in front of the body)
Example in sport
Upwards phase of a press up; rugby player making a tackle
Triceps
Function
Extension of the elbow (straightening the arm)
Example in sport
Shooting and chest passing in netball (execution phase)
Biceps
Function
Flexion of the elbow (bending the arm)
Example in sport
Drawing a bow in archery; 'backscratch' position during tennis serve
Abdominals
Function
Flexion of the spine (sitting upwards)
Example in sport
Performing a sit up or a forward roll
Latissimus dorsi
Function
Adduction of the shoulder (moving the arm down towards the mid-line of the body)
Example in sport
Hitting in hockey – left shoulder during preparation, right shoulder during execution and recovery
Gluteals
Function
Hip extension (moving the femur backwards)
Example in sport
Pulling leg back at the hip before kicking a ball
Quadriceps
Function
Extension of the knee (straightening the leg)
Example in sport
Kicking a ball (execution and recovery phase)
Hamstrings
Function
Flexion of the knee (bending the leg)
Example in sport
Performing a hamstring curl on a weights machine; preparation phase of a rebound jump in basketball
Gastrocnemius
Function
Plantar flexion of the ankle (pointing the toes downwards)
Example in sport
Standing on tiptoe to mark a shot in netball or pointing the toes during a gymnastic or dance move