The isokinetic strength profile of semi-professional soccer players according to low back pain

BACKGROUND: Soccer as a sport has a very high injury rate and low back pain (LBP) is considered to be the most common overuse injury typically occurring in the back and spine in elite soccer players. OBJECTIVE: This study aimed to investigate differences in knee muscle strength and muscle imbalances in soccer players according to lower back pain. METHODS: One hundred and thirty-six male professional soccer players (20.49 ± 3.73 years, 76.57 ± 8.24 kg, 182.63 ± 6.73 cm) volunteered for the study. The isokinetic dynamometer PrimaDOC (EASYTECH, Italy) was used to assess the hamstring and quadriceps strength at the selected speeds of 60∘/s, whereas the Roland-Morris Disability Questionnaire (RDQ) was used as a health status measure to assess physical disability caused by low back pain. RESULTS: A univariate analysis of variance has shown that there is a statistically significant difference among the groups divided into Absolut peak torque right knee flexors, Absolut peak torque left knee flexors, Ratio between hamstrings and quadriceps strength right leg, Ratio between hamstrings and quadriceps strength left leg based on the RDQ scores. On the other hand, no other significant differences among the groups were found in other parametersCONCLUSION: The current study indicates that knee muscle strength variables, resulting from an isokinetic testing, have the potential to discriminate between soccer players with and without a history of low back pain. However, low back pain is a multidimensional phenomenon and knee muscle strength or imbalance alone cannot be expected to explain low back pain.