RSSProprioception, Kinaesthesia & Neuro-muscular control
October 28, 2009 by David Fitzgerald
|
| Print
Filed under Movement Impairments, Physiotherapy Blog
As clinicians we often use these terms interchangeably to describe the phenomena of altered limb sensation or control. However, researchers classify each component separately on the basis that there are different physiological mechanisms underlying each component.
- is considered the cumulative neural input to the CNS from mechano-receptors located in the joint capsules, ligaments, muscles, tendons and the skin. Other terms that are often used synonymously with proprioception include ‘kinaesthesia’ and ‘balance’.
- is the conscious awareness of joint position and movement resulting from proprioceptive input to the CNS.
- refers to the ability to maintain the centre of gravity over the base of support without falling. The ability to maintain balance requires the integration of proprioceptive input from the periphery and afferent information from the eyes and vestibular apparatus in the inner ear.
Appropriate use of this terminology is important among clinicians to enhance communication and understanding in this area.
In the last decade clinicians have been increasingly interested in the use of closed chain exercises on the basis of their enhanced proprioceptive value. This is partly on the basis of the similarity to functional loading and the presumption that the total proprioceptive input is more likely to activate the appropriate neural pathways. Closed chain exercise results in the simultaneous motion of all joints in the extremity, which thus requires co-ordinated muscle activity to control all the segments in the limb.
Here lies the challenge for us clinicians because the attraction of such a massive sensory of bombardment is obvious, but the trade off is the inability to accurately quantify the contribution of individual muscles and the specific area of breakdown. If we take ‘single leg squat’ as an example and look at the typical areas of breakdown as determined from observational analysis we might observe some of the following:
1) Increased pronation.
2) External tibial rotation (out toeing).
3) Valgus knee.
4) Medial femoral rotation.
5) Adducted femur.
6) Laterally displaced pelvis.
7) Pelvic drop or elevation (trendelenberg or disguised trendelenberg)
8) Pelvic rotation.
9) Trunk deviation.
10) Balance reactions using the upper limbs.
The challenge as clinicians is to determine the zone of breakdown and the compensatory mechanisms. The dilemma of functional loading is to stimulate proprioceptive input where the sensory feedback is usually far less distinct than isolation of a specific region in a non-functional position. Treatment strategies therefore involve some element of “aspiration” that there will be transfer of muscle recruitment and position sense from specific exercise positions into functional situations. Therein lies the challenge – to go specific or go general.
There certainly appear to be a group of patients where any physical stimulation is sufficient to activate some level of useful muscle function and significantly impact symptoms.
There also appear to be a group of patients who are reasonable active but present with more specific muscle imbalance issues related to patterns of activation.
There are also patients who are systemically hypermobile with a pre-disposition to low tone. They are dependent on specific stimulation to maintain status.
And then there are those who are stiff, who are usually structurally more robust, appear to have better intrinsic tissue characteristics and can be less vigilant about maintaining muscle tone. They may however require more of a flexibility focus.
Such is the tapestry of life but worth remembering as it influences the nature of our patient management and the type of advice given – very important if we are to be credible messangers.
Enjoy the clinical challenge.
David.
