Posterior Pelvic Tilt During the Squat: A Biomechanical Perspective and Possible Exercise Solution

(1) Background: The squat is a compound exercise used in sports, physiotherapy, and activities of daily living. Posterior pelvic tilt during the squat, commonly referred to as “butt wink” can potentially increase the risk of spine injury when performing a squat with posterior pelvic tilt. The main goal of this study is to objectively assess the immediate effect of the exercise intervention on the total pelvis range of motion in the sagittal plane (mainly posterior pelvic tilt) during squat. The secondary aim is to determine the relationship between the initial pelvic position and the occurrence of posterior pelvic tilt; (2) Methods: The study is a controlled experiment with 42 participants (21 females and 21 males) divided into an experimental group (n = 23) and a control group (n = 19). The division was made according to the incidence of posterior pelvic tilt during the performance of the bodyweight squat. A baseline measurement that included three-dimensional kinematic motion analysis and a physiotherapy examination and an outcome measurement that included only three-dimensional kinematic motion analysis were performed. Both groups underwent a twenty-minute exercise intervention aimed at strengthening stabilizing muscles, improving squat technique and body awareness in space. Data from the three-dimensional kinematic motion analysis were statistically processed using Restricted Maximum Likelihood analysis (REML) of linear mixed models and repeated measures analysis of variance (rANOVA); (3) Results: There was no statistically significant difference in the range of motion of posterior pelvic tilt before and after the exercise intervention (p = 0.89 and p = 0.42). Only the individual repetitions of the squat were statistically significantly different from each other (p < 0.001) and no statistically significant relationship between posterior pelvic tilt and initial pelvic position was found (p = 0.13); (4) Conclusions: The short exercise intervention did not affect the range of motion of posterior pelvic tilt during squatting, but it is still worth investigating this issue further and looking for possible associations between different variables of squat execution and the incidence of posterior pelvic tilt.