In a previous post, we detailed the latest research on the importance of ankle mobility on knee mechanics. During weight bearing the shin, tibia, must be able to move forward over the fixed ankle and foot. Without adequate ankle flexibility and shin moved over the foot to the inside placing the knee at risk of traumatic and overuse injuries. Conversely, patients with adequate ankle mobility and better able to keep their knee over their foot during a step down test. Granted, many of these patients may also have hip weakness, but the importance of ankle mobility should not be overlooked. New research supports the influence of ankle mobility on knee mechanics and stability.
In the Journal of Orthopedic and Sports Physical Therapy authors examined 30 healthy participants as they underwent biomechanical testing in a laboratory (Rabin et al. 2016). The participants were tested on a step down test and then underwent testing of ankle mobility. Authors then split the group in two based on either low or high degrees of mobility. As expected, the group with the least amount of ankle mobility demonstrated less knee stability and more knee movement than the group with better ankle mobility. Athletes and patients are encouraged to assess and treat limited ankle mobility for improvement in knee stability.