Kicking is a sporting gesture that generates high stress demands on the musculoskeletal system. The participation of the trunk in the kick has been studied since the flexion-extension and rotation moments of the trunk and pelvis can favor the energy transmission mechanism for the kicking lower limb. This allows the performance of the maximum kick with sharing of demands between the trunk and the lower limb. Thus, the magnitude of the joint moment produced in the trunk during the kick can influence the magnitude of the moment produced in the lower limb and the power of the kick. However, there are no reports on the existence of these possible relationships.

To investigate the relationship between bisegmented trunk moments (thoracolumbar and lumbopelvic) and kicking lower limb moments, as well as kick power (foot velocity pre-impact with the ball) in a maximum instep soccer kick.

Cross-sectional study carried out with eighteen male volunteers who practiced soccer as a recreational activity (1x/week, for at least 1 year and without musculoskeletal injuries in the last 6 months), between 18 and 35 years old, with a body mass index ≤ 25 kg/m². Data collection was carried out at the Movement Analysis Laboratory (LAM), at the Federal University of Minas Gerais (UFMG). The variables collected were the peak moment of ipsilateral thoracolumbar and lumbopelvic flexion and rotation, peak moment of flexion of the right hip, peak moment of extension of the right knee, and peak velocity of the foot pre-impact with the ball. Pearson's correlation analyzes were performed to investigate the relationships between trunk moment and lower limb moment and pre-impact foot velocity.

Peak thoracolumbar flexor moment had a moderate to good significant negative correlation with knee extensor peak moment (r= -.519, p < 0.05). Peak ipsilateral thoracolumbar and lumbopelvic rotator moments, and peak knee extensor and hip flexor moments had significant positive correlations, from moderate to good, with pre-impact foot velocity peak (.481≤ r ≥ .677 p < 0.05). Peak ipsilateral thoracolumbar and lumbopelvic rotator moments had significant positive correlations, from moderate to good, with peak hip flexor moment (r= .671, p < 0.01; r= .659, p < 0. 01, respectively).

There are relationships between the magnitudes of trunk moment, the magnitudes of hip and knee moments and kick power. There seems to be a compensatory relationship in which the knee extension moment is greater in those individuals who produce lower thoracolumbar flexion moment. In addition, more powerful kicks are related both to greater hip flexion and knee extension moments and to greater thoracolumbar and lumbopelvic rotation moments in the transverse plane.

The findings make it possible to explain possible mechanisms of stress demands that can lead to typical kicking injuries, providing the planning of prevention and rehabilitation strategies.