Table 2.
Comparisons for the thickness and activity of the lumbar stabilization muscles between different volitional preemptive abdominal contraction (VPAC) strategies and body positions.
| Variable | VPAC | Position | Interaction | |||||
|---|---|---|---|---|---|---|---|---|
| F | p | Post-hoc | F | p | Post-hoc | F | p | |
| Muscle thickness | ||||||||
| MF | 19.72 | <0.001 | AE, AD > NB | 20.07 | 0.001 | SLS, QTS > LYI | 1.94 | 0.147 |
| TrA | 63.22 | <0.001 | LYI: AD > AE, NB QTS: AD > AE, NB SLS: AD > AE, NB |
17.61 | <0.001 | NB: SLS, QTS > LYI AD: SLS > QTS, LYI AE: NS |
4.75 | 0.004 |
| IO | 28.78 | <0.001 | AD > AE, NB | 12.44 | <0.001 | SLS > QTS, LYI | 0.63 | 0.591 |
| EO | 24.07 | <0.001 | AD > NB > AE | 1.70 | 0.200 | NS | 1.87 | 0.120 |
| Muscle activity | ||||||||
| MF | 6.16 | 0.012 | AE, AD > NB | 36.57 | <0.001 | SLS, QTS > LYI | 1.01 | 0.375 |
| IO/TrA | 20.97 | <0.001 | AD > AE > NB | 15.29 | <0.001 | SLS, QTS > LYI | 1.02 | 0.363 |
| EO | 12.79 | <0.001 | LYI: AE, AD > NB QTS: AE, AD > NB SLS: AE, AD > NB |
20.86 | <0.001 | NB: SLS > QTS > LYI AD: SLS, QTS > LYI AE: SLS, QTS > LYI |
2.54 | 0.044 |
Abbreviation: VPAC = volitional preemptive abdominal contraction; MF = lumbar multifidus; TrA = transverse abdominis; EO = external abdominal oblique; IO = internal abdominal oblique; AE = abdominal expansion strategy; AD = abdominal drawing-in strategy; NB = natural breathing strategy; LYI = lying; QTS = quiet standing; SLS = single leg standing; NS: non-significant.