TOPIC 4.2: MOVEMENT ANALYSIS - joint and movement type

outline the types of movement of synovial joints and give sporting examples

• flexion - bending of the joint

  • bending of the elbow joint when playing tennis

• extension - lengthening/extending a joint

  • lengthening elbow joint to make a straight arm

• abduction - away from the centre of the body

• adduction - towards centre of the body, bring to body

• rotation - rotation towards or away from centre of the body

• circumduction - movement of a joint in a circular motion

• pronation - rotational movement in arm palm facing posteriorly

• supination - rotational movement in arm, palm is anterior

• inversion - feet towards middle of the body

• eversion - feet away from the body, on sides of feet

• plantar-flexion - top of the foot points away from leg, planting down

• dorsi-flexion - flexion of the ankle, foot points more superiorly

• elevation - raising a body part upwards

• depression - lowering a body part downwards

outline the types of muscle contraction

isometric

isotonic - concentric, eccentric

isokinetic

what is an isometric contraction

the muscle length remains constant

• no joint movement occurs

• e.g. plank, gripping a tennis racquet

what is an isotonic contraction

an increase in tension, which results in changes in skeletal muscle length, lengthening and shortening of a muscle

eccentric

• a lengthening contraction which occurs with gravity

  • e.g. bicep curl with the down/lowering phase

concentric

• a shortening contraction which typically occurs against gravity

  • e.g. bicep curl lifting/upward phase

what is an isokinetic contraction

where the muscle contracts and shortens at a constant rate of speed

• requires changes in load to maintain a constant speed throughout a range of motion

explain the concept of reciprocal inhibition

when one muscle contracts and the other relaxes (agonist and antagonist)

• a neuromuscular reflex which inhibits opposing muscles

what is the agonist

the muscle that contracts

what is the antagonist

the muscle that relaxes

what is the synergist

other muscles which support the agonist to create movement

whats the fixator/stabiliser

the muscle that allows the agonist to work and stabilises the origin

what is the origin

the tendon at the non-moving end/fixed

what is the insertion

the tendon at the moving end

analyse the movement of a bicep curl in relation to joint action and muscle contraction

elbow flexion

• agonist - bicep

• isotonic concentric

• antagonist - tricep

• relaxes

elbow extension

• agonist - bicep

• isotnic essentric

• antagonist - tricep

• relaxes

what is DOMS (delayed onset muscle soreness)

muscle soreness that is typically felt 24-48 hours after exercise

• can be due to

  • eccentric contractions

  • beginning a new program

  • a change in sports/activities

  • increase in duration/intensity of sport

• results primarily from eccentric contractions and is thought to be a consequence of muscle damage, inflammatory reactions within the muscle, overstretching, or overtraining

  • e.g. running down the stairs

how can DOMS be prevented/minimised

• reduce the eccentric component of muscle actions during early training

• start training at low intensity and gradually increase intensity

• warm up before and after exercise

• follow the 10% rule

  • avoid making sudden changes in duration/intensity that is over 10% of load at the moment