Box jumps have to be one of the most misunderstood exercises out there. This article is in response to seeing a lot of box jumps on social media that simply defeat the purpose of the exercise, yet people are in awe of these videos that they see. So if we first look at how a box jump should be performed, and what it is good for, then consider what box jumps are not, by the end of the article you should have a pretty good idea of how to correctly include this exercise in your training routine.
How to Perform a Box Jump Correctly
A box jump should be performed with a soft foam box in order to maximise the reduction in eccentric stress upon landing. After all, the purpose of the raised box is to reduce eccentric stress (a box jump entails less compressive stress than landing from a vertical jump and less shear stress and compressive stress at the knee compared to a broad jump) so why would you use a hard box for this? Box jumps can therefore be particularly good in lower limb rehab scenarios where the player is not yet ready to be exposed to the full eccentric demands of landing on the ground (think 8-10x ground contact forces upon each landing).
The Importance of Hip Displacement
Taken from @lachlan_wilmot twitter, https://twitter.com/lachlan_wilmot?ref_src=twsrc%5Egoogle%7Ctwcamp%5Eserp%7Ctwgr%5Eauthor, Head of Athletic Performance at the Parramatta Eels
When it comes to box jumps, hip displacement (i.e. how high your hips travel) is key. If you look at the photos above, you will see that the athlete’s hips reach the same height during his flight for both the 75cm box jump and the 105cm box jump – i.e. he has jumped the same height, the only difference is the amount of knee flexion upon landing. Yet telling someone you do box jumps with a 75cm (30 inches) box sounds nowhere near as impressive as telling them you do it with a 105cm (41 inches) box does it?
The difference in the two jumps is about the amount of hip flexibility required in order for the athlete’s feet to land 30cm higher for the higher box. Extremely high box jumps are almost always the product of a pretty good jump and fantastic hip mobility rather than pure explosive power . As a general rule of thumb you never want to land on a box which requires you to land with more than 135 degrees of knee flexion due to increased risk of knee and spine injury and if you are required to land with more than 90 degrees of knee flexion then the box is already too high .
So what happens when you start landing on a 30 inch box with less than 90 degrees of knee flexion? You simply jump higher and land softly (improved landing mechanics) – the training adaptation is still the same. The only good exception to this rule that I have come across is the similarities between the deep catch position required in the clean and a very high box jump . Yet this is with a very niche population – for the vast majority of us using box jumps to improve athletic performance this is not relevant.
How Not to Perform a Box Jump
So if that is what box jumps are and how they should be implemented, then what are they not?
Box Jumps are Not Plyometrics
Dr Yessis contends that ‘plyometrics is the most misused term in our vocabulary’ . When it comes to the world of strength and conditioning, it’s hard to disagree.
A true plyometric makes use of Dr Verkoshansky’s principle of ‘The Shock Method’, that is, a ‘sharp, compulsory muscular tension, initiated by the body’s impact (collision – e.g. ground reaction forces) with an external object’ . Specifically, this was used to refer to the training exercise he created in the 1960s called the Depth Jump, arguably the most revolutionary exercise of the 20th century .
A true plyometric exercise, one which makes use of ‘The Shock Method’, is thus very different to simply a jumping exercise. It is used to develop true explosive power, and thus can only be performed for up to approximately 10 jumps per session – not multiple sets of 10 jumps. Unfortunately, however, nowadays all kinds of jumping exercises are referred to as plyometrics.
Put simply – a box jump is a jumping exercise, not a plyometric exercise – it lacks the ‘shock’ required to be a true plyometric.
Box Jumps are Not a Conditioning Tool
Secondly, box jumps are not a conditioning tool. If, as discussed above, the purpose of using box jumps is to reduce eccentric stress, why perform multiple reps on a hard box therefore accumulating a significant amount of joint stress?
Additionally, landing mechanics start to falter under fatigue causing the risk of injury to significantly increase, not to mention the ingraining of poor landing mechanics. You want to practice how you perform – practise poorly, perform poorly. Of course, the caveat to this is their use in Crossfit – but even then I would argue that just because you have to express a certain ability in competition, does not mean you develop that ability in the same way.
In conclusion, box jumps can be an excellent tool if used correctly. They should be performed on soft foam boxes in order to maximise the reduction in eccentric stress upon landing. Hip displacement is the key performance indicator for box jumps, not the height of the box that the athlete lands on. It must also be remembered that box jumps are not a plyometric exercise nor should they be used as a conditioning tool.
Written by Joshua Bridgeman, Head of Performance at Rigs Fitness, Birmingham
References Eric Bach, ‘Stop Doing Box Jumps Like a Jackass’, https://www.t-nation.com/training/stop-doing-box-jumps-like-a-jackass (accessed 23/08/2018).  Jason Ferruggia, ‘How to Do Box Jumps Properly’, http://jasonferruggia.com/how-to-do-box-jumps-properly/ (accessed 23/08/2018).  Max Aita & Chad Wesley-Smith, The Jugglife Podcast Q&A episode.  Dr. Michael Yessis, ‘Dr Yessis on Prof. Verkoshansky and the Shock Method’, https://www.youtube.com/watch?v=NFS9oc-vLQ0 (accessed 23/08/2018).  Natalie Verkoshansky, ‘Shock Method and Plyometrics: Updates and an In-Depth Examination’, http://www.verkhoshansky.com/Portals/0/Presentations/Shock%20Method%20Plyometrics.pdf (accessed 23/08/2018)  Yuri Verkoshansky & Natalie Verkoshansky, Special Strength Training Manual for Coaches (Rome, 2011), p. XI.