The importance of proprioceptive training

Proprioception – taking a balanced approach to sport

 

When it comes to sport performance, power, strength and endurance can only take you so far. Whether you’re a footballer dribbling the ball, a gymnast on the bars, or a rugby player diving for the line while fending off tackles, balance is absolutely critical for performance. John Shepherd takes a look at how balance and proprioceptive training and the mechanisms that lie behind this skill can be improved.

Balance in sport involves a complex interplay between numerous factors. A number of these are conscious – such as deciding to move a limb to prevent yourself falling at the same time as performing a skill eg a basketball shot – while many more are unconscious. The unconscious element involves the ‘use’ of in-built sensory mechanisms and programmed responses. This is known as ‘proprioception’. Proprioception has been called the ‘sixth sense’ and is basically a mechanism (or, more accurately, a series of mechanisms) that keeps track and control of muscle tensions and movement in the body.

When you consciously make movements or are subjected to external forces, your muscles, ligaments and joints will be making their own ‘judgments’, based on the information that they receive from their own sources. These judgments are then used to invoke mechanisms to control movement (more about this later). These mechanisms are known as sensorimotor processes, and scientists have been investigating how the senses consciously and subconsciously react with one another to control movement (known as sensorimotor research). Sports scientists now believe that sensorimotor ability and proprioception can be enhanced by specific practices.

Mechanics of proprioception

Proprioception is achieved through muscles, ligaments and joint actions using messages that are continuously sent through the central nervous system (CNS). The CNS then relays information to the rest of the body literally ‘telling’ it how to react and with what amount of tension/action. Some of these instructions go to the brain, where more often than not they are acted on unconsciously, whilst others go to the spinal cord, where they are acted on automatically.

Proprioceptors are basically ‘sensors’ that reside within muscles, joints and ligaments. These respond to pressure, stretch and tension and are key in initiating what is known as the ‘stretch/reflex’. You will probably be familiar with the stretch/reflex as a mechanism in the everyday sporting context when trying to stretch a muscle beyond its sticking point – a point will be reached when the muscle will not want to stretch any further. This is the result of the stretch/reflex mechanism kicking in and trying to prevent the muscle from being stretched further.

Although not so readily apparent, the stretch/reflex also provides control over other functions eg your postural muscles, which maintain the balance of the body against gravity. This makes it a global as well as specific site muscle mechanism. An example of this is if you were holding a weight in your outstretched hand and then had more added; the stretch/reflex would attempt to make the adjustments necessary to allow you to continue to hold the added load by ‘tweaking’ all the supporting muscles and influencing your posture.

Injury can impair proprioception

Injury can reduce the effectiveness of an athlete’s proprioception, something that the athlete and coach may not be fully aware of even when rehabilitation seems complete. A team from the University of Pittsburgh looked at the role of the sensorimotor system as it relates to functional stability, joint injury and muscle fatigue of the shoulder and the restoration of functional stability after shoulder injury (1). They noted that to fully restore shoulder stability, deficits in mechanical stability, proprioception and neuromuscular control are needed.

Specificity and proprioception

The rule of training specificity states that the greatest sports improvement gains will be derived from the most sport specific exercises for that sport. Thus for example, a sprint athlete will get greater returns from plyometric training, in comparison with weight training. However, it is possible that even these specific training means may not fully develop proprioceptive ability.

Mark Alexander, writing for PP’s sister publication Sports Injury Bulletin, notes that a focus on speed and power exercises, with their emphasis on fast-twitch muscle fibre may in fact disrupt proprioceptive ability (3). He indicates that fast-twitch muscle fibre is less adept at monitoring and controlling muscle tension when compared with slow-twitch fibre because of the quicker speed of neural impulses being sent and interpreted through muscle spindles and spinal motor neurons.

Thus it is argued that balance type exercises need to be performed at slower paces to optimally enhance proprioception. These allow postural stabiliser muscles, with their greater predominance of slow-twitch muscle fibre, to supply enhanced movement control. An example of a stabilising muscle is the soleus muscle of the lower leg, while the other major calf muscle (the gastrocnemius) is the ‘fast-twitch fibre rich prime mover’.

Balance type drills are seen to improve not only proprioception, reducing potential injury, but also the ability of an athlete to express power. To explain this, think of a high jumper planting off their curved approach to leap dynamically skyward. The forces going through the athlete’s prime mover leg muscles need to be controlled by the stabilising muscles. The more effective these muscles are, the more effective the power output will be from the prime movers. This is akin to the fine-tuning of a race car’s suspension (which can be equated to the stabilising muscles), where small tweaks can greatly enhance the geometry of the car and therefore the speed produced by its prime mover – the engine.

To counter the thoughts of those who might still advocate faster movements for the development of proprioception, it is necessary to differentiate between proprioception and kinaesthetic awareness. Kinaesthetic awareness is about the ability of an athlete to perform a dynamic sporting skill, perhaps from an unstable position, and involves the conscious control of the body in space and time in order to affect a sports skill. This differs from the more automatic nature of proprioception responses. 

Original version available here.

References

1. J Athl Train 2000; 35(3):351-363
2. www.chekinstitute.com
3. www.sportsinjurybulletin.com/archive/strength-training-injuries.html