Table 2 Y Balance Test-Upper Quarter (YBT-UQ) side differences and performance and tennis-specific performance by level of training experience
Outcome | YoT: <2 (n = 14) | YoT: 2–5 (n = 17) | YoT: 6–8 (n = 11) | p-value (ƞp2) |
|---|---|---|---|---|
YBT-UQ: side difference | ||||
LSI for the medial reach [% AL] | 4.7 ± 3.3 | 3.8 ± 2.8 | 3.9 ± 2.8 | 0.700 (0.02) |
LSI for the inferolateral reach [% AL] | 11.5 ± 8.1 | 9.4 ± 7.7 | 5.3 ± 3.2 | 0.105 (0.11) |
LSI for the superolateral reach [% AL] | 9.4 ± 7.8 | 7.5 ± 4.9 | 6.3 ± 5.3 | 0.437 (0.04) |
LSI for the composite score [% AL] | 6.6 ± 4.3 | 4.3 ± 2.9 | 2.5 ± 1.9 | 0.012 (0.20) |
YBT-UQ: performance | ||||
SA: medial reach [% AL] | 115.5 ± 10.2 | 111.6 ± 8.9 | 105.3 ± 9.9 | 0.040 (0.15) |
SA: inferolateral reach [% AL] | 100.7 ± 12.1 | 106.2 ± 10.9 | 99.4 ± 11.3 | 0.245 (0.07) |
SA: superolateral reach [% AL] | 80.0 ± 10.7 | 76.8 ± 10.0 | 76.8 ± 11.1 | 0.663 (0.02) |
SA: composite score [% AL] | 98.7 ± 8.5 | 98.2 ± 6.0 | 93.8 ± 10.0 | 0.272 (0.07) |
NSA: medial reach [% AL] | 116.3 ± 8.9 | 110.7 ± 8.5 | 105.8 ± 12.3 | 0.037 (0.16) |
NSA: inferolateral reach [% AL] | 105.0 ± 10.8 | 108.7 ± 10.3 | 101.4 ± 13.3 | 0.257 (0.07) |
NSA: superolateral reach [% AL] | 78.2 ± 12.3 | 75.2 ± 12.3 | 77.8 ± 12.2 | 0.770 (0.01) |
NSA: composite score [% AL] | 99.8 ± 7.7 | 98.2 ± 6.6 | 95.0 ± 10.6 | 0.348 (0.05) |
Tennis-specific performance | ||||
Flat serve velocity [km/h] | 160.4 ± 18.9 | 158.6 ± 16.7 | 150.8 ± 15.3 | 0.357 (0.05) |
Slice serve velocity [km/h] | 145.1 ± 19.0 | 141.5 ± 16.1 | 129.4 ± 15.8 | 0.071 (0.13) |