Author(s): NUTARELLI, S., FATTINI FELLINI, G., TRENTINELLA, G., COMFORT, P., FILARDO, G., Institution: ENTE OSPEDALIERO CANTONALE, Country: SWITZERLAND, Abstract-ID: 2127

INTRODUCTION:
Anterior cruciate ligament (ACL) injuries strike male and female players, the latter at an alarmingly higher rate in soccer when adolescents.
Hamstring (HS) strength and the isokinetic HS/quadriceps concentric ratio (HQr) proved their value in knee and HS injury prevention. This study investigated the effect of a validated 45-minute soccer match simulation protocol (SAFT45) on lower limb strength, motor control, and functional tests on young female soccer players (FP).
METHODS:
Fifty 14- to 19-year-old FP underwent strength, motor control, and functional tests before and after completing a SAFT45. Strength was measured with a Nordic hamstring test (NT), an isokinetic test at 90°/s, a 90-90 isometric HS test, and a countermovement jump (CMJ). Functional and motor control tests comprised the side hop and single hop tests, and the single leg (SL) squat test was scored with the Qualitative Assessment of SL Loading scoring system (QASLS, from zero = best to 10 = worst score).
RESULTS:
Pre- Vs post-SAFT45 HS mean and absolute eccentric peak torque, and work in the NT showed no differences. Isometric HS peak force and the rate of force development (RFD) recorded at 0-100/150/200 ms time intervals in the 90-90 isometric HS test showed no pre- Vs post-SAFT45 differences, but the decrease from 300.8 ± 220.7 N·s-1 pre- to 215.4 ± 197.1 N·s-1 post-SAFT45 (p=0.046) on the left legs. Pre- Vs post-SAFT45 isokinetic differences of HS and quadriceps absolute and relative peak torque showed no differences. The isokinetic pre- (66.4% ± 14.1) Vs post-SAFT45 (71.7% ± 14.7) HQr difference increased for the left legs (p=0.025). FP showed a pre- (0.3 ± 0.1) Vs post-SAFT45 (0.3 ± 0.1) CMJ decreased modified reactive strength index (jump height/time to take-off, p=0.006), countermovement displacement (pre = 24 ± 4.3 cm Vs post = 23.4 ± 4 cm, p=0.037), and propulsive force (pre = 1030.1 ± 186.8 Nm Vs post = 1013.2 ± 182.9 Nm, p=0.049). SL squat QASLS scores improvement (1.8 ± 1.0 on the R limb and 1.8 ± 0.9 on the L leg, both p=0.0005) showed motor control impairment. No difference in pre- Vs post-SAFT45 side hop and single hop tests.
CONCLUSION:
SAFT45 did not impact strength in NHE, isometric HS, isokinetic tests, and functional tests. A clear post-SAFT45 worsening effect emerged in the CMJ explosive lower-body power parameters. Motor control showed a significant drop. FP lose lower limb explosiveness and motor control after completing a soccer match simulation protocol.