Table 4. Standardized mean difference and 95% CI for iEMG from comparisons between starting phases of each muscle and for both backstroke start variants. Phase Biceps Brachii Triceps Brachii Tibialis Anterior Gastrocnemius Medialis Rectus Femoris Biceps Femoris Upper limbs horizontally positioned Hands-off vs Take-off .01[-.76,.77] -.46[-1.26,34] -.42[-1.25,.41] 1.83[.64,3.03] 2.61[.85,4.37] .37[-1.53,2.27] Hands-off vs Flight .96[.14,1.77] -1.65[-2.30,-.99] -1.35[-2.09,-.60] -.15[-.96,.66] 1.52[.27,2.77] .14[-2.05,2.32] Hands-off vs Entry .92[.03,1.82] -1.57[-2.23,-.91] -1.07[-1.84,-.29] -.08[-1.00,.84] 2.44[.54,4.34] -1.53[-2.71,-.35] Take-off vs Flight 2.32[1.07,3.58] -.86[-1.54,-.17] -1.02[-1.78,-.25] -1.36[-2.14,-.58] -.42[-1.17,.32] -.09[-1.05,.88] Take-off vs Entry 2.25[.60,3.89] -.21[-1.04,.62] -.71[-1.51,.09] -1.31[-2.14,-.48] -.06[-.96,.84] -.72[-1.47,.04] Flight vs Entry -.05[-1.21,1.11] 1.61[.03,3.20] .41[-.51,1.34] .10[-1.00,1.19] .53[-.64,1.70] -.63[-1.46,.21] Upper limbs vertically positioned Hands-off vs Take-off -.38[-1.18,.43] -.43[-1.13,.27] -.31[-1.04,.42] 1.61[.51,2.71] 1.39[-.03,2.82] .00[-.90,.90] Hands-off vs Flight .74[-.11,1.59] -.93[-1.60,-.26] -1.06[-1.76,-.35] -.43[-1.19,.33] .87[-.06,1.80] -.40[-1.43,.63] Hands-off vs Entry .62[-.31,1.54] -.53[-1.21,.16] -.46[-1.19, .27] .00[-.99,.98] 1.75[.51,2.99] -1.27[-2.15,-.40] Take-off vs Flight 1.46[.43, 2.48] -.99[-1.68,-.30] -1.22[-2.01,-.42] -1.45[-2.19,-.71] -.29[-1.09,.51] -.40[-1.43,.63] Take-off vs Entry 1.29[.16, 2.43] -.19[-.97,.58] -.24[-1.11,.62] -1.15[-1.99,-.30] .20[-.69,1.09] -1.27[-2.15,-.40] Flight vs Entry -.14[-1.13, .86] 1.77[.51,3.03] 1.17[.22,2.12] .58[-.65,1.80] .81[-.36,1.98] -.69[-1.50,.11]