How to Jump in the Sand!This was posted to the About.com Volleyball Forum in response to a question regarding how to jump in the sand. The analysis was so good i decided to include it in our Instructional Series.
The question asked about how to jump and if part of the problem dealt with the pronation of the feet.
The answer is:
You're correct about "pronation" being a problem - while indoors you want to pronate in order to add additional height to your vertical leap, just the opposite is true outdoors in soft sand - here's why:
When you pronate, you bend your foot downward at the ankle and concentrate essentially all your body weight on the small forward portion of your foot (i.e., toes and balls of your feet) rather than over the entire area of your foot, such as when you are standing flat-footed - thus, your entire body weight/downward jumping force is concentrated on a very small area of each foot and you do end up "sinking" into the sand. The trick in the sand, is to jump "flat-footed".
Indoors, pronating is no problem as the resiliency/stiffness of the floor adequately resists the concentrated weight and resulting downward forces on your toes/balls of your feet from your body which arise of your upward jumping movements. In fact, strongly pronating your ankle/foot and coordinating same with the rest of your jumping mechanics, results in a significantly higher indoor jump.
Outdoors, the situation is quite different. When you pronate in soft sand, the soft sand doesn't have nearly the same resiliency/stiffness as the indoor court. When you pronate and jump at the same time, you will find that your feet/toes literally seem to sink downwards into the sand, thereby taking away from your vertical jump. This is directly the result of focusing all your body weight/downward jumping forces onto the very small area of your toes and balls of your feet - the result being that your feet are quite literally forced downwards into the sand much like pushing a pin into a pin cushion.
Instead of pronating, you need to learn to jump flat-footed. When you watch a
good beach player with lots of vertical jump, carefully watch these three
1) last step in the approach - the player will most often make a bounding "hop" of short-to-medium length into a "flat-footed" landing on both feet at the jump take-off point - this packs the soft sand down under their feet and makes for a much more resilient/stiffer jumping surface which will better respond to the explosive downwards jumping forces;
2) crouchdown/skeletal-muscular system pre-load - the player will extend both arms either low the the sides and back while at the same time crouching into what is best described as a "half-squat" with equal weight on both legs/feet (weight spread out over the entire foot with just slightly more weight on the toes than on the heals, for proper balance) and a partially bent-over back - this stores potential jumping energy by stretching the major muscle groups used in jumping (legs, buttocks, back) thereby readying them for the explosive contraction movements and readies the arms for the strong upswing motion which occurs at the very beginning of the leap just prior to the major muscle groups exploding (note: the strong upswing actually "unloads" a portion the inertia of the arms and a portion of the upper body from the major muscle groups during jumping as the momentum gained from the upswing literally "throws" the upper body into the air as the upper body starts its "unwinding" from the partially bent over position of the "half-squat". The upper body (i.e., your back muscles) can then unwind in a more exlosive manner (again, this acts to throw your upper body upwards thereby gaining vertical momentum and reducing the inertia that the legs/buttocks muscles have to contend with) starting just prior to the explosion of the legs/buttocks major muscles. Another benefit of the arm upswing is that the arms at the very beginning of the jump, is that the arms are then in the proper position for either blocking or the hitting "take-away" at the start of the spiking swing.
3) feet/ankles - in the half-crouch, the ankles are half-bent (as they must be when the player hops into the half-squat prior to jumping) and the feet are kept flat with the sand through the explosion off of the sand. During the explosive legs/buttocks muscle group contraction, you concentrate on jumping "up off your feet" rather than "up off your toes". This means that the muscles in the lower leg explosively contract so that the half-bent ankles are brought back to just a little past the normal standing right-angle 90 degree position rather than being strongly pronated downwards at nearly a 45 degree down angle as would occur indoors (note: at great jumping player might pronate fully in follow through once he/she is in the air, but at the instance of jumping up off of the sand, their feet will be at the nearly 90 degree flat-footed position).
The result is that all the downward jumping forces are concentrated over the largest possible area of both entire feet. The sand can thus better resist the downward jumping forces with the result that the player will not sink downwards and the player will jump significantly higher.
While this might seem overly complicated, it is exactly what occurs when you watch high-speed videos of sand jumping mechanics. If you learn to do it right, you will definitely get more "hops" than you ever believed possible!
Just remember the proper sequence of body movements (arm swing-upper back/body-legs/buttocks - all in an explosion of strength taking place in much less than 1 second) while jumping off the flat-footed base. Something else that will really help is a good pliometric jump training program which will help you with developing an explosive jump - you might go to the "JumpUSA" website at "www.jumpusa.com" and check out what they have to offer - my 16 year old son Bryan used the JumpUsa program and his vertical went up 7" in 6 weeks with a simultaneous great increase in footspeed!