US Patent 9630081 Elastic training apparatus

An elastic resistance training apparatus for the performance of ankle plantar flexor resistance exercises, dorsi flexor resistance exercises, ankle inverter resistance exercises, or ankle everter exercises by a user. The apparatus comprises an elastic cord with a primary loop at each end configured to engage the dorsum and plantar surfaces of the user's foot. An auxiliary loop is connected to the primary loop and configured to engage the user's calcaneus bone when the primary loop engages the dorsum and plantar surfaces of the user's foot centering the apparatus at the talocrural joint to enable the user to perform talocrural joint movements without the apparatus disengaging from the user's foot during resistance exercises.