In vertical jump training the posterior chain receives a lot of recognition, but does it really trump the level of importance the anterior chain plays? It is a very good question. After all we all want to jump as high as possible in as little time as possible and wasting months of training on a muscle group that doesn't add much in terms of jumping improvement is not something anybody wants to do.
As it is a topic that vertical jump athletes discuss frequently we thought it was about time for some Verticaljumping.com analysis.
The posterior chain is the group of muscles that runs from your lower back down behind your legs, hence the name, posterior. These muscles include the lower back, the glutes, the hamstrings, and also the calves.
The muscles in the posterior chain are important for jumping for several reasons. The first one is that due to their size they generally have plenty of potential to generate a lot of power for your jump. The second reason they are important is that the glutes generally have one of the highest ratios of fast twitch fibers in the whole body.
In terms of the actual jumping motion itself the posterior chain is involved as follows. As you bend your knees and descend down into the eccentric phase, the hamstrings contract. The more powerful your hamstrings are, the more forcefully you will drop down. The quicker you can get down, the higher you will jump.
On the concentric or upward part of the jump, your leg muscles including the quads (anterior chain), glutes, lower back and calves work together to produce powerful contractions to extend the hips, knees and calves (the triple extension) and throw your body skywards. Once again, the more power these muscles can produce in the triple extension the higher you can jump.
The muscles that comprise the anterior chain are often referred to as the beach muscles. These include the chest, abs, and quads. For the purposes of vertical jump training though we can probably not worry too much about the chest.
The anterior chains role in vertical jumping is as you would imagine, the opposite of the posterior chain. As you descend into the negative portion of a jump the quads lengthen in an antagonistic fashion to the hamstrings. Then after the lengthening they are required to reverse that downward motion and powerfully contract back again to extend the knees and hips and drive your jump high.
The abs also contribute by contracting in the downwards portion of the jump and lengthening in the upwards phase. If you have powerful abs they will assist you in improving the negative or downwards part of the jump.
Without getting all philosophical here I think Newton summed up this debate best when he said "for every action there is an equal and opposite reaction". He may have been talking about our two muscle chains.
The reality is that both the anterior chain an the posterior chain are very important for your vertical jump. You cannot jump high with a strong set of quads and a weak glutes and hamstrings. Conversely you cannot expect to jump high if your glutes and hamstrings are strong and your quads are weak.
Well know strength and conditioning coach Dan Blewett suggests that when it comes to vertical jump the posterior chain contributes about 60%, the quads about 30%, and everything else (abs, calves, etc) chips in with 10%.
Another thing to consider is the type of jumping you are doing. Single leg jumps like the track and field disciplines, and single leg dunking require a lot more glute and hamstring strength than the two foot jumps.
This is due to the higher levels horizontal force generated as part of the single leg jump run up. If you are training for the track and field jumps, or are a single leg jumping athlete than it is probably a good idea to spend more time on developing the posterior chain muscles.
From a strength perspective the posterior chain is developed using deadlifts, kettlebell swings, glute bridges, hip thrusts, and leg curls. The single leg jumps such as bounding and skipping drills, as well as sprinting, and the running jumps themselves.
However there are also a couple of exercises in our Game Changers book that are designed to really hit the posterior chain in ways that are very specific to increasing your vertical jump. These exercises are designed specifically to rapidly increase strength and power in the key jumping muscles and have been tried and tested by thousands of athletes wanting to jump higher.
Most of these exercises are not available anywhere else besides Game Changers. To find out more click on the image below.
We know it is a bit an anti-climax of an answer to suggest that they are bothequally important, but it is true. They ARE both important. Imbalances in the strength and power between the muscles of the two chains not only reduces performance (i.e jump height), but is also one of the quickest ways to injure yourself. If you have a deficiency in one area, whether it be your anterior muscles or your posterior muscles, the first thing you should focus on is rectifying that deficiency.
It is mentioned on our site a number of times that identifying and ironing out your weaknesses, followed by a balanced approach will ultimately yield faster, and more sustainable improvements. This article almost certainly won't end the debate for some people, but we hope it gives you some good food for thought.