Jumping - the effect of shoes and socks?

[perfphysio]

This is just an interesting clinical observation I made yesterday when treating a runner with ankle pain.

I was doing some horizontal jumping on a pilates reformer and noticed that the client had a problem in the ability of soleus to take the load at the initial point of impact. This was not the case on the good side, although it did happen on occasion. As the clients feet were slipping on the landing board due to the wearing of socks I asked her to remove them and continued.

What I then noticed was the the poor leg was performing well. I repeated it several times with and without socks to see if I was imagining things but I was not. This got me thinking about the effect of increase sensation to the foot both in takeoff and landing.

1. Is the brain using both information from the foot pressure (forces) during take-off and using memory to work out how much force to absorb in the landing?

2. If so do socks impede the accurate information processing of this information? I suggest take-off is just as important as landing because when you sit on a wall for 5 mins and then jump down onto your feet you often get a jarring sensation to the achilles as it locks the ankle on landing (i.e. perhaps it never understood the dynamics of the landing because their was not initial takeoff?)

3. If this is correct is it therefore important to train landing initially by maximizing the sensory input - by training with bare feet, no cushioned trainers which might interfere with the processing of the information even more than socks alone.

4. If three is correct then should shoe companies design shoes and socks for jumping that contain little dampening features are the ball of the foot? This may be especially important for sports such as basketball.

:smokin

Any and all comments welcome

In my opinion, I don't think that going barefoot would make much of a difference to ankle stability. Most of the input that the brain uses to process the information would be proprioceptive, i.e. joint position and movement sense, rather than light touch or pressure input at the skin. I don't think wearing shoes would have much of an effect on proprioceptive input. Anyway, I would think the cushioning and dampening features of shoes and socks would be important to protect athletes from overuse syndromes.

As for jumping off a wall from a sitting position, the reason why you get a jarring sensation is because your body isn't upright - rather, your feet are in front of your centre of gravity. This means you can't flex your knees too much or you'll fall over backwards - hence your knees remain relatively straight and can't absorb shock as efficiently.

Anyway, this is just my opinion. Anyone else agree or disagree?

[Physiobase]

I am sorry but I have to completely disagree. The increased sensation of barefeet definately has an effect on the brains appreciation of those take-off pressures. This appears to have some type of influence on the "perceived" forces that were generated at take-off, which must later be required to be combined with the joint position sense during the landing phase. i.e. less force perception at take-off = less eccentric preparation on landing!

Anyone else with a comment?

I would think the pressure perceived during take off is contributed by the increased tension of the connective tissue and joint range proprioception. 1x body weight on the feet before take off is always going to be 1x body weight no matter how high or far you are planning to jump. Perhaps the socks are too slippery :lol

[Physiobase]

Good point, but that assumes you reach terminal velocity on the way down. I think not in a typical jump.