Upper Extremity Performance, Balance and Core Endurance in Adolescent Soccer Players

Soccer is one of the most popular sports in the world with a large number of players under the age of 18. High physical demands, frequent changes in exercise intensity and a large number of movement profiles require optimal physical capacity for both adult and child players in soccer.

Physical Performance Tests (PPT) are used to provide a detailed overview of functional status, to predict injury or to decide on return to sport. Physical performance is assessed using closed or open kinetic chain tests; however, in athletic populations, closed kinetic chain PTs may allow for more comprehensive assessments than open kinetic chain PTs.

Balance is one of the important factors determining sportive performance. It provides neuromuscular control by integrating central nervous system stimuli from the environment to maintain postural control on unstable surfaces during sports activities. Soccer is often played on unstable surfaces (e.g., jumping on grass, kicking the ball while being blocked by an opponent), and the factors affecting players' balance are greater than in other sports. This suggests that soccer players need to have a more dynamic balance compared to other athletes.

The core is the power center of the body with the abdominal muscles on the front, paraspinal and gluteal muscles on the back, diaphragm on the roof, oblique abdominal muscles on the sides, and pelvic ring on the floor. The core acts as a muscular corset to stabilize the trunk with or without limb movement. Core stability enhances effective control of the trunk and stabilization of posture and provides a fundamental basis for force generation and transmission between the upper and lower extremities.

The continuity of the kinetic chain is required for biomechanically and kinesiologically correct performance of upper extremity functions during daily life activities. The kinetic chain is a system that enables different body parts to produce and transfer power in coordination. The system creates minimal stress, maximal power generation and transfer in the kinetic chain, thus supporting the movement in the distal segments. In order to ensure minimal loss in power transfer between the extremities and trunk, trunk stabilization with a strong core is required.