Angular Velocity, Moment, and Power Analysis of the Ankle, Knee, and Hip Joints in the Goalkeeper's Diving Save in Football

Abstract

The aim of this study was to identify biomechanical characteristics of goalkeeper's diving performance in football. Lower extremity joints powers, moments, and angular velocities, were investigated in seven elite goalkeepers diving to save balls, shot from a ball canon to unanticipated heights (high and low) and sides (right and left). Our result showed that there was a proximal-to-distal sequence for each leg in timing of peak joints powers (p < 0.05). Hip extensors produced the largest (p < 0.05) peak moment, the contralateral (relative to dive side) peak was significantly larger than the ipsilateral one for high (4.56 ± 1.02 N·m·kg −1 , and 3.52 ± 0.79 N·m·kg −1 ) and low dives (3.52 ± 0.79 N·m·kg −1 , and 2.52 ± 0.56 N·m·kg −1 ). The ankle plantar flexors produced the second largest peak moment (p < 0.05), and the peak ipsilateral ankle power and angular velocity were the largest (p < 0.05) of all joints, during high (1,502 ± 338 W, and 14.73 ± 1.36 rad·s −1 ) and low dives (868 ± 263 W, and 14.14 ± 3.09 rad·s −1 ). Strength and conditioning coaches need to focus on hip extensors and ankle plantar flexors, and for specificity in power training that should elicit triple extension of the lower limbs' joints in a proximal-to-distal sequence.

On-Field Biomechanical Assessment of High and Low Dive in Competitive 16-Year-Old Goalkeepers through Wearable Sensors and Principal Component Analysis

“…Although the majority of previous studies on goalkeepers’ diving biomechanics were conducted on a sample size between 6 and 11 participants [ 1 , 2 , 3 , 8 ], one recent study estimated that a sample size of 16 participants would be required to obtain a power of 0.8 with an effect size of 0.25 and a alpha level of 0.05 [ 6 ].…”

“…The diving save is the most frequent and critical task for football (soccer) goalkeepers [ 1 , 2 ]. Goalkeepers’ dives are explosive defensive jumps aimed at reaching the ball and preventing the opposite team from scoring [ 3 ]. For keepers, saving goals is as fundamental as scoring is for strikers [ 2 ].…”

“…For keepers, saving goals is as fundamental as scoring is for strikers [ 2 ]. For these reasons, measuring the movement quality and effectiveness of dives allows to establish goalkeepers’ performance and determine their value [ 2 , 3 ], especially in football academies.…”

“…Studies regarding goalkeepers’ diving are limited to the investigation of penalty kick strategies [ 3 , 5 , 6 ] and the quantification of anticipatory times [ 2 , 7 ]. Indeed, the literature on goalkeepers’ kinematics is scarce and lacks sample power (most of the studies have a sample size between 6 and 11 players), ecological dynamics perspective (all in-lab settings), and involvement of academy players (all >18-years-old players involved) [ 1 , 2 , 3 , 8 ]. Moreover, no previous study accounted for full-body kinematics or tried to extract “relevant” features from the multitude of variables involved.…”

Injuries and Pain Associated with Goalkeeping in Football—Review of the Literature

“…Non-contact injuries are caused by dynamic movements, including quick changes of direction, sprints, dives, jumps, throws, and kicks. Jumps and shot stopping, as well as diving saves, require large and rapid generation of forces at push-off [11,[26][27][28] and include many diving techniques, which mostly end in hitting the ground [12]. Therefore, it is reasonable to anticipate that shot stopping training can lead to contusions, bruises, abrasions, wounds and even fractures [29].…”