Low Back Pain and Hamstring-to-Quadriceps Strength Ratio in Military Personnel

Participants were asked whether they had experienced low back pain during the past 12 months (yes/no). Participants who responded "yes" were classified into the low back pain group.

LBP intensity was assessed using the Visual Analogue Scale (VAS, 0-10) , where 0 - no pain, and 10 - worst imaginable pain.

Participants were asked to indicate LBP duration. LBP pain duration was classified as acute (<3 months) or chronic (≥3 months)

Muscle strength was assessed using the Biodex System 4 isokinetic dynamometer. Participants were instructed to avoid vigorous physical activity 24 hours before testing and refrain from eating for at least 2 hours prior to assessment. A 10-minute warm-up on a cycle ergometer (50-60 W) and light dynamic exercises were performed before testing. Participants were seated with the backrest at 85° and hip flexion at 90°. The dynamometer axis was aligned with the lateral femoral epicondyle, and the lower leg was secured 2-3 cm above the ankle. The range of motion was set from 70° knee flexion to full extension. The trunk and tested limb were stabilized using straps.

Testing included 5 repetitions at 60°/s and 10 repetitions at 120°/s, with a 30-second rest interval between sets. Prior to testing, participants performed 3-5 familiarization repetitions.

Peak torque normalized to body weight (Nm/kg) was recorded.

Was measured in Nm

in W

Measured in kg

Measured in meters

Measured in years

Participants were asked whether they had lumbar or lower limb injuries during the past 12 months that could influence the results (yes / no).