Jumping performance and muscle-tendon characteristics of Maasai men of East Africa

The male Maasai of East Africa perform a ritual of repetitive jumping ceremonies and are known anecdotally for outstanding jumping performance. The aim of the present study was to assess vertical jumping ability and anatomical/biomechanical characteristics of Maasai jumpers. Twenty-two Maasai men performed maximal vertical countermovement jumps (CMJ), and repetitive jumps (RJ) on an instrumented force plate. Twelve age-matched Norwegian men served as controls (CON). Anthropometrics, kinematic/kinetic and electromyographic data were recorded during jumping. Resting and dynamic plantarflexor muscle architecture and Achilles tendon stiffness were measured using ultrasonography. Maximal jump height (CMJ and RJ) was similar between groups, however the Maasai jumped faster, with less vertical displacement, and greater ground-reaction peak forces and power in CMJ. In contrast, greater vertical displacement in RJ was seen for the Maasai compared to CON. The Maasai demonstrated longer relative leg length, and tendon structures, but lower fascicle pennation angles, shorter fascicle lengths and more compliant tendons. Although maximal jump height was similar, jump kinetics and kinematics differed between groups, which may relate to jumping tradition or to anthropometrical and/or muscle-tendon morphological/mechanical characteristics. Overall, the observed muscle-tendon characteristics of the Maasai may favor economy of movement during walking and perhaps during RJ.