Tai Chi and Balance - Proprioception of the Knee and Ankle

A  study published by the British Journal of Sport Medicine shows that elderly people who regularly practice Tai Chi not only show better proprioception of the ankle and knee joints than sedentary people. Which would explain why Tai Chi improves balance in its practitioners.

Not only long term Tai Chi practitioners have better ankle and knee joint kinesthesis than sedentary controls but also their ankle joint kinesthesis is better than regular swimmers/runners. Furthermore, the latter did not perform any better in ankle and knee joint kinesthesis tests than their sedentary counterparts. 

 

The postural control system is the control circuit between the sensory sources, the central nervous system, and the musculoskeletal system. Proprioceptors and visual and vestibular (internal ear) centres contribute information to the central nervous system on body position and balance.

Other studies also showed that :

• All age groups are more dependent on proprioception than on vision for the maintenance of balance.
• Disruption of proprioceptive input was the most important determinant of quantitative balance performance in subjects older than 80 years.
• Different kinds of exercise have different effects on balance. Comparison of the effects of proprioceptive exercise, bioenergetic physical activities (swimming, cycling, or jogging), and no exercise on postural control in elderly people shows that muscular strength was significantly increased in the bioenergetic exercise group, but proprioceptive exercise appeared to have the greatest effect on balance control.

Swimming and running are two of the most common exercises practiced by elderly people; they are excellent forms of aerobic exercise, and provide good training stimuli for cardiopulmonary function and muscle strength. Compared with Tai Chi, swimming and running involve cyclic repetitive actions. But awareness of joint position and movement is not emphasized during these exercise forms but highly in Tai Chi. This probably explains why the swimmers/runners did not have better scores for knee and ankle kinesthesis in this study.

It is interesting that the effects of Tai Chi on proprioception were different in the knee and ankle joints. An old Tai Chi proverb states, “In Tai Chi, the feet act as roots”. Also most Tai Chi forms are performed in a low position, which puts load on the muscles which stabilize hip, knee and ankle. The continuous changes of stances and steps cause more variations in ankle joint position, (toes or heels outward or inward, up or down). 

Moreover, while making a stride, feet moves are slow and deliberate. "Control your weight, don't let your weight control you".

These movements greatly improve and help to retain the sensitivity of proprioceptors located in the joint capsules, ligaments, tendons, and muscles.

Ankle proprioception is very important for the elderly to maintain proper postural control. When it comes to control of postural stability, the elderly rely more on hip movements, while young people rely on ankle movements. Therefore the impact of Tai Chi on ankle proprioception is of great benefit in improving and maintaining balance in old people.

The decline in proprioception with age is an important contributing factor to falls in the elderly. This study shows that, compared with other common activities, long term Tai Chi exercise is more valuable for maintaining balance control in the elderly. 

Practice, Slow... 

 

Tai Chi, Balance & Proprioception

Proprioception is a combination of senses that informs the central nervous system about where the various parts of the body are located and moving in relation to each other (Kinesthesia) and in relation to our environment, and that helps us keep our balance. Proprioception is what allows us to to walk in complete darkness without losing our balance. The main organs involved in proprioception are the inner ear, the eyes (sight), skin (sense of touch), and the stretch sensors located within muscles, tendons and joints.

With proprioception, you can estimate the position of your foot on the ground, the angle of your calf with it, and the amount of weight spread between the ball and the back of your foot.

Proprioception continuously gathers input from millions of sensors in your muscles, joints, and ligaments, combines that with input from sight and touch and uses it all to control your balance, coordination, posture, and movement.

Kinesthesia is the part of proprioception that is mostly interested in the localization of the body parts in relation to each other. The sense of equilibrium or balance involved in proprioception is usually excluded from Kinesthesia. An inner ear infection might degrade your sense of balance, which would degrade proprioception, but not kinesthesia. You would be able to walk by using your sense of sight to maintain your balance but would be unable to walk with your eyes closed.

2 simple exercises to illustrate the influence of the senses of sight and touch on proprioception. Try them.

Influence of Sight on balance.

Stand on both legs. Raise on foot at about knee level. Keep your balance for 10 seconds (count until 10). If you cannot hold it for 10 seconds, try to count how long you can hold it. Put your foot back on the ground.

Now close your eyes and repeat the same exercise. Unless you have already trained for it, you will find it much more difficult to hold on your balance with your eyes closed.

Influence of Touch on Kinesthesia.

Stand on both legs with your feet together. Step up to the front and right with your right foot. Land your right foot at 45 degrees to your front right. Slightly bend both knees. Very slowly, lift your right foot from the ground and bring it back toward your left foot and then to your right back. Land your right foot at 45 degrees to your right back. DO NOT touch the ground while doing so. Pay attention to how easy this move is for you.

Now repeat the same exercise but when you move your foot back, let your big toe gently slide on the ground. It should become much easier this way.

The reason why it is easier with your foot slightly dragging on the floor is that your sense of touch provides information to your central nervous system about where your foot is located. When your foot stays off the ground, the only organs that inform your brain are the sensors within muscles and joints. Once the foot slightly touches the ground, then the sense of touch provides an additional information, which makes things much easier. This information about the position of the foot is of course also helpful to help us keep our balance

Training can improve proprioception.

The ability to play piano or wield a sword requires a finely-tuned sense of the position of the joints. This sense can and needs to be trained to enable a person to concentrate on other aspects of the performance such as reading the music or seeing where the other opponents are.

 

Because of the low speed and stretching moves involved in their practice, Chi Gong in general and Tai Chi in particular are excellent ways to enhance proprioception for adults.

In future posts I will propose simple exercises to train and enhance proprioception.