Introduction: Performing weighted squatsas a strength training exercise is practiced in several sports. To minimize the risk of injury during squats, it is considered important to maintain the neutral position in the lumbar spine. There is limited knowledge of objective measurable factors that explain why the lumbar spine commonly deviates from the neutral position during a squat.

Aim: To study the relationship between anthropometry, range of motion, muscle recruitment pattern,movement control and movementof the lumbar spine during a barbell back squat

Method: The study was a cross sectional study with an experimental design with a targeted selection of powerlifters and Olympic weightlifters. Data collection from 19 study participants included measurement of lumbar movement during a squat with a barbell bar, examination of anthropometric properties, mobility of hip, knee and ankle and movement control tests of the lumbar spine at low load. Linear regression analysis was used to investigate which factors are associated with flexion motion in the back during a squat.

Results: There was a relationship(R2 value= 0,41 for the left and 0,37 for the right)between dorsal flexion of the ankle jointsand flexion of the lumbar spine during a squat performance. There was also a relationship(R2 value= 0,23) between medial hip rotation on the right side and flexion of the lumbar spine.

Conclusion: The mobility in dorsal flexion of the ankle joint affects theflexionmovement in the lumbar spine during a barbell squat exercise.