1. Centre of Gravity & Proprioception

2. Proprioception
Agility , Balance and Coordination controlled by proprioceptors
Proprioception is fundamental to correct performance – which requires good agility, balance and coordination
Proprioception is the body’s ability to transmit position sense ( from receptors in body) , interpret the information and respond accordingly (unconsciously or consciously)
Play an important role in posture control and movement
Proprioception is what allows us to know what position our body is in with out looking at our body parts
It is proprioception that gives us the agility to change direction , to maintain our balance and the coordination to produce the activity
Proprioceptors are afferent nerves that receive and send impulses from stimuli in skin ,tendons , joints and muscles to the CNS

3. Receptors Cutaneous receptors – afferent receptors in the skin
Joint receptors
Afferent receptors that lie in the joint capsule and the ligaments of the joint
Muscle spindles
Stretch of the muscle
Golgi tendon organs
tension within muscle

4. CNS
One afferent nerves have sent input to the CNS the body’s motor response is determined by the location with in the CNS that interprets the stimuli and initiates the efferent reaction
Spinal cord
Spinal reflex – simplest form – protection
Joint under excessive stretch – sudden activation of muscle reflex flexion to reduce the load
Brain Stem
Primary proprioception centre – maintain positions or posture
Cerebral cortex
Highest level of the brain – here correct movement is learned – conscious becomes automatic

5. Balance
Balance is fundamental to most activities – required for even simple activities – standing
Balance must be restore following injury or re-injury may occur
Balance influenced by vestibular , visual and proprioceptors
Vestibular – inner ear -Semi circular canals
vestibular –Occular reflex – allows eyes to remain steady when body is in motion
Oculomotor - - vision providing feedback about the relative position of the body in space
if not interpreted correctly – a good example – car that is stopped at light and car beside you moves forward you think you are moving back wards
Skaters – visual fixation – focusing on one object to avoid getting dizzy
Test – Rhomberg , stork .. Line walking ( eyes open , eyes closed )
Exercise begin basis and move to more complex

6. Centre of gravity Point in body around which weight is balance
Harder to find in body because of its irregular shape
Anatomically speaking around S2
Slightly higher in men than women
CoG changes as body moves
The lower the CoG the more stable

7. Line of gravity / base of support
An imaginary line that runs vertically through the CoG
Used to determine stability of an object
Base of support is a two dimensional area between and including the objects ( person) point of contact
Can change base of support – wider stance more stable , feet together easier to get pushed over
Object is most stable when line of gravity falls with in base of support
if this line falls outside of the base it is difficult to maintain balance

8. Coordination
Coordination is the complex process by which a smooth pattern of activity is produced
Several muscles involved and must provide accurate response in both timing and intensity to be coordinated
Development – start with simple activities – with repetition
Progressions simple to complex

9. Agility
The ability to control the direction of the body or segment during rapid movement
Required flexibility , strength , power , speed balance and coordination
Agility highly advance skill – provides base for speed – however speed must be accompanied by coordination
Tests – sports – lateral running , T – tests , figure 8’s, stop starts
Exercises again should start simple and move to more complex and to be work or sport related

10. Regaining postural stability and balance
Is both
Static
Dynamic
Dynamic for example, walking, climbing stairs, etc

11. MOVEMENT STRATEGIES
What are the 3 movement strategies that are used by the body to maintain the CoG within a stable base of support?
1. ankle
2. hip
3. stepping

12. MOVEMENT STRATEGIES When would each strategy be used?
Ankle: when small, slow movements, close to CoG
Hip: larger, quicker movements required. Also if CoG gets closer to LOS.
Stepping: if CoG gets out of Limit Of Stability.

13. INJURY AND Proprioception
Studies of the knee and ankle show that there is a decrease in proprioceptive feedback from damaged ligaments to the CNS (sensory/afferents).
Therefore, there is a decreased reflex excitation of motor neurons (efferents) to the muscles responsible for preventing sway/controlling balance.

14. Proprioceptive Training
Proprioception exercises should be a routine part of a rehab program
Balance first – then coordination followed by agility
Static then dynamic exercises
Simple to complex
Exercises must be safe, yet challenging
Stress multiple planes of motion
Incorporate a multi-sensory approach / distractions
Progress to sport-specific
Multiple planes of motion – flexion vs extension, adduction vs abduction
Multisensory approach – eyes open vs eyes closed
Begin with static, bilateral, stable. Progress to dynamic, unilateral, unstable.
Various surfaces – wobble boards, pillow, trampoline, etc
Sport specific exercises are always done last

15. BALANCE TRAINING static:
CoG is maintained over fixed base of support on a stable surface.
i.e. Rhomberg tests

16. 2. semi-dynamic: 2 types
(a) maintain CoG over fixed base of support while on moving surface or unstable surface (BAPS/Wobble board)
(b) transfer CoG over a fixed base of support to areas within the LOS while standing on a stable surface (pick up pens)

17. BALANCE TRAINING
3. dynamic:
CoG maintained within the LOS, while over a moving base of support on a stable surface.
Requires a stepping strategy
i.e. hopping, walking on a balance beam
More into plymetics – hopping, climbing, jumping, up stairs, down stairs, etc
Ex dynmaic test for basketball player – shuffle side to side on their own
Functinal/sport specific – have the basketball player mimic the motions of the trainer

18. Balance Training 4. functional:
same as dynamic, except also have sport specific tasks included.
i.e. catching/throwing a ball while running.