Bad ankles can decrease your vertical jump. You can have a strong and powerful hip, but ultimately force has to travel through the ankle. The ankle muscles contribute significantly to jump height [1], but they also ‘link’ hip and knee extension into the ground.
Normal energy transfer and biomechanics are a product of decent levels of dorsiflexion (bringing the foot upwards) range of motion and toe flexor strength. These qualities were covered in the following research.
Methods
18 injury-free volunteers participated in this study [2].
Three measurements were collected:
- Peak Toe Flexor Muscle (TFM) Strength
- Ankle Dorsiflexion Range of Motion (ROM)
- Countermovement Jump Height (CMJ).
Correlation coefficients were then drawn between these tests.
Results
There was a high correlation between first TFM (big toe) strength and CMJ height.
There was also a moderate correlation between Dorsiflexion ROM and CMJ height.
Takeaway
Lacking strength at the big toe (first TFM) could lead to energy loss at the ankle joint. Strengthening the toe flexors has been shown to increase jump performance [3].
Fix: Strengthen the big toe by curling it into the ground when accelerating upwards in extension-based movements (squats, deadlifts, calf raises, and vertical jumps).
Lacking dorsiflexion ROM causes the heels to come off the ground early during the jump. This leads to a greater horizontal shift rather than a vertical shift of the center of mass, causing less efficient vertical displacement (jump height) [4].
Fix: Improve ankle dorsiflexion ROM by performing Banded Tibialis Raise (shown here).
or
BY performing ankle rocker exercises. They are a part of the French Contrast Method in the Vertical Jump Protocol:
- Toes-Up Single-Leg Squat x 10 reps ea.
- Ankle shuffle x 20 reps ea.
REFERENCES
[1] Robertson, D. G. & Fleming, D. (1987). Kinetics of standing broad and vertical jumping. Canadian Journal of Sports Sciences, 12(1), 19-23.
[2] Yun, S. J., Kim, M. H., Weon, J. H., Kim, Y., Jung, S. H., & Kwon, O. Y. (2016). Correlation between toe flexor strength and ankle dorsiflexion ROM during the countermovement jump. Jouranl of Physical Therapy Science, 28(8), 2241-4.
[3] Goldmann, J. P., Sanno, M., Willwacher, S., Heinrich, K., & Brüggemann, G. P. (2013). The potential of toe flexor muscles to enhance performance. Journal of Sports Sciences, 31(4), 424-33.
[4] Papaiakovou, G. (2013). Kinematic and kinetic differences in the execution of vertical jumps between people with good and poor ankle joint dorsiflexion. Journal of Sports Sciences, 31(16), 1789-96.
