Trunk muscles influence lower limb performance in crossfit athletes: A cross-sectional study.

Introduction: Crossfit is a sport that combines cardio-respiratory and muscle endurance, strength, flexibility, muscle power, speed, coordination, agility and balance. However, there is no information in the literature regarding functional performance of the lower limbs and the endurance of core muscles in this population. The objective of this study was to evaluate the correlation between trunk strength/endurance and lower limb function through lower limb symmetry and balance tests.

Methods: Forty-one young adults aged 19-41 years (26.3 ± 5.4) participated, 15 sedentary and 26 cross fit practitioners for at least one year. The tests were as follows: Biering-Sørensen Test of trunk extensor endurance, Trunk Flexors Endurance Test at 60°, Side Plank Endurance Test, Lumbar Dynamometry, Single-Leg Hop Test and Star Excursion Balance Test.

Results and discussion: Although there were higher values, there was no significant difference (p > 0.05) between the groups for lower limb symmetry and strength of trunk flexor muscles. For balance, strength and resistance variables of trunk extensor muscles, the values found were higher in crossfit practitioners than in sedentary subjects.

Conclusion: There is a relationship between trunk muscle strength and endurance and lower limb balance. Moreover, cross fit athletes showed higher values of trunk muscle strength/endurance and lower limb balance compared to sedentary adults.