How does ankle mobility affect jump height?
Often when coaches look to improve athletes jump height they look immediately at lower body strength and power. This is for good reason as both of these have a significant impact on an athlete’s ability to jump higher. As previously discussed both jump training and Olympic lifting improve lower body power and sprint performance. Also eccentric strength seems to be a strong predictor of vertical jump height.
Although strength and power are key factors in an athlete’s ability to jump higher, there are also biomechanical factors at play. One such factor is the athlete’s ankle range of motion. When an athlete’s range of motion at the ankle is altered it can change jumping mechanics and as a result reduce the height that the athlete is able to jump.
This has been shown in a study by Pappaikovou in 2013 which investigated the effects of ankle joint range of motion on vertical jump, and drop jump performance. This study used physical education students, which were separated into 2 groups: inflexible group, and flexible group. As expected the flexible group out performed the inflexible group in both the vertical jump and the drop jump by an average of 2 centimetres.
What is more interesting is that the flexible group used larger range of motions during their jumping tasks, while the inflexible group were unable to attain the same range of motion and lifted their heels off the ground during maximal jumping tasks. Finally during drop jump the flexible group showed greater control and joint coordination. While the inflexible group displayed altered mechanics leading to decreased performance.
The results from this study illuminate the need for adequate range of motion for performance. With reduced ranges of motion, the movement patterns for said task are altered. This leads to decreased performance, and potentially injury. In this example ankle range of motion was looked at for its effects on jump performance and as expected, reduced range of motion at the ankle reduced the performance of jumping tasks. Because the performance of the task was altered by the reduced ankle range of motion these athletes may be performing the jumping in an unsafe way. This could lead to overuse injuries down the line.
If you are looking to assess ankle range of motion consider using a CKC ankle touch to wall test, or the overhead squat. When evaluating the CKC you are looking for the athlete to have equal dorsiflexion in each ankle. For the overhead squat test the athlete should be able to perform a full range overhead squat without the need of plates under the heels and without the feet or knees collapsing in. If your ankle range of motion is limited you can look at some previous articles that I have written which will give you strategies to correct this imbalance [HERE] and [Here].
Remember that there is more to good performance than just strength and power. While strength and power are important, other factors can result in the inability of athletes to fully express their strength and power. It is important to keep in mind range of motion and movement deficiencies when looking at athlete performance.