Have you ever wondered how it is that you are able to walk without falling over? How you can drive without paying any attention to your arms and legs while working the pedals and steering wheel? Or how you manage to put food in your mouth without watching your hand while you do something completely unrelated? These are just a few examples of actions that we take for granted in our everyday lives. These are however also examples of proprioception.

What is Proprioception?

Proprioception is defined as the ability to establish a sense of limb position in space. This simply put translates into knowing where your limbs are and what they are doing at any given time. This ability allows your body to react properly to external forces (pressure of another object, the gradient of the terrain) and to sense and control your limbs and movements 6,8,9.

Proprioception is achieved by means of mechanoreceptors (sensory receptors or information collectors found within your bodies tissues). These mechanoreceptors detect motion in joints, muscles, tendons and the associated deep tissues and generate nerve impulses (sensory messages) which are transported to and processed in the Central Nervous System (CNS). These impulses provide information about joint position, motion, vibration and pressure. The information received is then relayed from the CNS to the rest of the body with information about how to react to the forces and with what amount of tension 7, 10, 12.

As stated previously, anything that involves moving your arms or legs in a precise way without looking at them requires proprioceptive awareness. This awareness is something that is so automatic that it is often overlooked but is as important as any of your 5 senses 1.

What is the difference between Proprioception and Balance?

The misconception is that proprioception is reliant on balance. This is however incorrect as balance has to do with fluid equilibrium within the inner ear 1 whereas proprioception has to do with nerve impulses to and from the brain about the joints 12. They are however interrelated.

Why is Proprioception Important?

Proprioceptive awareness acts as a protective mechanism to your body 4. It enables your body to autocorrect when an unaccustomed movement occurs. This is all well and good when everything is working optimally but when an injury occurs important networks may be disrupted.

Example:

In the ideal situation: imagine running along when you step into a hole and your ankle rolls outward. Immediately the mechanoreceptors within the ankle joint and related tissues identify an abnormality in your normal pattern and send a message to the CNS to inform it of the problem. The CNS responds by sending a reply message back to the ankle to readjust accordingly to help rectify the abnormal movement and prevent any damage occurring.

In the not so ideal situation: imagine the same circumstances as before but this time there is a breakdown in the communication network at some point resulting in a delayed reaction of information transfer leading to injury.

The benefits of proprioceptive training are vast. Proprioceptive training leads to improved joint stability 3,8,11. The quicker you can regain your balance and proprioceptive awareness, the safer your movements will become 6,8. It has been identified that as your balance improves, you become less prone to injury as a result of improved neuromuscular communication. Improved balance not only improves reaction time, co-ordination, speed and agility but also assists in a greater generation of power 5,6,8,.

How is Proprioception Effected when an Injury Occurs?

When an injury occurs, nerve endings and pathways are damaged resulting in impaired muscle action. This leads to impaired balance and co-ordination and reduced joint position awareness (especially if the mechanoreceptors have been damaged). Re-education of damaged mechanoreceptors is vital in returning the injured joint to a perceived sense of stability 9, 12 this is where proprioceptive rehabilitation comes in.

The biggest risk of injury is having had a previous injury and thus proprioceptive rehabilitation is so vital to re-educate damaged mechanoreceptors and neural pathways.

When to Include Proprioception:

Proprioception training is most commonly used in the rehabilitation of injuries but is becoming increasingly popular as a method of injury prevention. When considering injury, even a strong joint can be injured when exposed to an unaccustomed activity (stepping into a hole while running) 2,7. Sports injuries in particular can lead to poor performance of the mechanoreceptors and thus a disruption in the transportation of information to and from the brain and to the rest of the body 8.

Proprioceptive and balance exercises should begin as soon as possible. These activities can begin even before the individual is weight bearing (in a seated position, with feet on a wobble board rocking back and forth in a pain free range of motion) and can be progressed along with the rehabilitation program (progressions discussed in exercise examples) 12.

Types of Proprioception Exercises:

Many people are unaware of the fact that proprioception applies to both the upper and lower parts of the body. Think of the example in the introduction in part 1 of this article where proprioception is explained as being able to put food in your mouth without watching your hand move. It is therefore important to include proprioception when experiencing any type of injury of the lower OR upper limbs or joints.

Generally speaking, any type of training will work on your proprioceptive awareness, 8 however there are certain activities that are used to assist to train your proprioception directly. These include: yoga, pilates, balance conditioning, agility and certain jumping movements among other activities 7.

When beginning proprioceptive exercises (as with any exercise) it is important to progress at a safe and appropriate rate. Obviously you do not have to start with the non weight bearing exercises if you are fully weight bearing but don't start jumping if you are battling to stand on one leg for example.

General exercise progressions:

1. Non weight bearing - correct foot placement while using crutches ? seated with feet on a wobble board rocking back and forth in a pain free range of motion

2. Weight bearing - balancing on a flat, stable surface ? balancing on an unstable surface (flat ? uneven) ? Jumping ? Walking/ running (agility)

All exercises should progress from double leg ? single leg. Eyes open ? eyes closed. Arms positioned to aid balance ? dynamic arm movements including catching and throwing objects.

Lower Limb Exercise Examples:

Upper Limb Exercise Examples:

Will Proprioception Training Prevent Injury?

The majority of research indicates that proprioceptive training is effective in developing better balance and coordination, thus reducing the chance of injury. The goal behind proprioceptive exercises is to help you restore stability and neuromuscular control. The combination of rehabilitative and proprioceptive exercises has been found to be most effective 3,9.

References:
1. www.wisegeek.com/what-is-proprioception.htm
2. www.sportsmedicine.about.com/cs/conditioning/a/aa062200a.htm
3. www.cat.inist.fr/?aModele=afficheN&cpsidt=15006472
4. www.doeatc.k12.hi.us/pnfankle.pdf
5. www.proprioceptivetraining.net/
6. www.cyber-spy.com/ebooks/ebooks/Proprioceptive-Training-A-key-to-sports-success-(ebook).pdf
7. www.thefinalsprint.com/2007/01/help-prevent-injuries-by-performing-proprioception-balance-training/
8. www.streetdirectory.com/travel_guide/7715/recreation_and_sports/proprioceptive_training_a_key_to_sports_success.html
9. www.biomech.com/full_article/?ArticleID=384&month=10&year=2006
10. www.thefreedictionary.com/proprioceptive
11. www.medical-dictionary.thefreedictionary.com/muscle+tone
12. Brukner. P, Khan. K. 2008. Clinical Sports Medicine (Third Edition)

Cindy Coles
SharkSmart Intern Biokineticist