THE EFFECTS OF MOTOR IMAGERY AND ACTION OBSERVATION-BASED PLYOMETRIC TRAINING ON MUSCLE ARCHITECTURE AND JUMP PERFORMANCE OF ADOLESCENT SOCCER PLAYERS

M. Emirzeoglu^1,2, O. Ulger¹

¹Hacettepe University, Physical Therapy and Rehabilitation, Ankara, Turkey, ²Karadeniz Technical University, Physiotherapy and Rehabilitation, Trabzon, Turkey

Background: Lower limb muscle-tendon injuries are the most common injuries in adolescent soccer players. Although it is known that plyometric training (PT) improves muscle function, the effects of neuroscience-based PT on the muscle morphological structure are unclear.

Purpose: The primary aim of this study was to examine the effects of combined motor imagery and action observation-based (MI+AO) PT on the pennation angle (PA), muscle thickness (MT), and fascicle length (FL) of the vastus lateralis (VL) and biceps femoris long head (BFlh). The secondary aim was to evaluate the effects of training on jump performance.

Methods: Thirty-six healthy adolescent soccer players (age: 13.91±1.05 years, height: 1.62±0.10 m, weight: 52.09±8.33 kg) were randomly assigned to PT (n=17) or control (n=19) groups. Athletes in both groups continued their routine training programs. PT group also participated in 3 sessions of training per week for 8 weeks. The PT consisted of 10 different exercises, and a total of 3480 jumps. Athletes watched the prepared videos and imagined jumping. Muscle images were taken using the Soundcam mobile ultrasound probe, and then analyzed with MicroDicom software. The single leg hop test was used to evaluate jump performance. Outcomes were assessed at baseline, 4, 8, and 12 weeks.

Results: There was no significant change in the muscle architecture parameters in the control group for 8 weeks (p>0.05). The VL PA was higher on the dominant (mean difference=2.40±3.45°, 95% CI 0.76° to 4.04°, d=0.77, p=0.01), and non-dominant side (mean difference=3.32±3.75°, 95% CI 1.53° to 5.79°, d=0.84, p=0.01) in the PT group at week 4. Similarly, there was a significant increase in dominant (mean difference=0.15±0.19 cm, 95% CI 0.07 to 0.23 cm, d=0.68, p=0.03) and non-dominant side (mean difference=0.24±0.23 cm, 95% CI 0.14 to 0.35 cm, d=1.17, p=0.01) VL MT. These increases were higher at week 8 in terms of dominant side VL MT (d=0.82, p=0.02) and non-dominant side VL PA (d=0.86, p=0.01). Except for the dominant side BFlh MT (mean difference=0.21±0.31 cm, 95% CI 0.06 to 0.36 cm, d=0.87, p=0.03), there were no significant changes in VL FL, and other BFlh architectural parameters (p>0.05). Even if dominant side improve, non-dominant side jump performance was statistical higher in the control group at week 8 (mean difference=10.12±12.82 cm, 95% CI 4.36 to 15.9 cm, d=0.57, p=0.03). Both sides jump performance was significantly better in the PT group at weeks 4 and 8 (mean difference=16.71±11.76 to 22.88±12.19 cm, 95% CI 11.1 to 28.7 cm, d=0.84 to 1.29, p<0.01). Significant changes in muscle architecture and jumping performance were maintained during follow-up (p>0.05).

Conclusions: This research provides the first evidence that MI+AO PT increases the VL PA, VL MT, BFlh MT, and improves jumping performance. It is recommended that future studies be conducted in athletes with injuries to examine static and dynamic muscle architecture according to PT phases.

Implications: MI+AO PT can be added to the routine training programs of healthy adolescent soccer players in order to improve the muscle architectural structure and jumping performance.

Funding acknowledgements: The authors received no financial support for the research.

Keywords:
Neuroscience
Ultrasonography
Athletic performance

Topics:
Sport & sports injuries
Musculoskeletal: lower limb
Orthopaedics

Did this work require ethics approval? Yes

Institution: Health Sciences University Trabzon Kanuni Training and Research Hospital

Committee: Clinical Research Ethics Committee

Ethics number: 2022/59