Biomechanics of Hips in Kayak Rolling

Hip biomechanics in kayak rolling is a relatively under examined topic, unlike the forward stroke, which has been well researched because of its importance in athletic performance. In kayaking, the roll is an advanced life-saving maneuver and is the best rescue for dynamic water. Solid contact with the kayak itself is required with the lateral hip abut to the interior hull of the kayak. The anterior and slightly medial portion of femur to the femurs distal end, the knee joint, is also abut beneath the kayak deck. Rolling requires an explosive hip “snap” from an underwater recovery position, essentially activating the hip through a “knee drive” or forceful hip flexion while the opposite hip joint extends, to provide a platform of support that does not detract from the force exerted by contralateral flexion. The sequence of iliopsoas, rectus-femoris, sartorius, tensor fascia latae flex on one side and the gluteus maximus, biceps femoris, semimembranosus, semitendinosus extension on the contralateral side combine to create the movement. In this study, the sequence of muscle activation and percentage of maximum volume contraction were explored. Where the bulk of the power and when synergy of muscle contraction is most crucial were also examined. Altered kinematics, such as femoracetabular impingement, was also evaluated to provide evidence of the importance of proper mechanics and its influence on biomechanics of the roll. Also, how differently shaped kayaks alter the angles of thigh connection, or how rolling in different circumstances were also examined