Foot posture influences the electromyographic activity of selected lower limb muscles during gait

Table 2 Effect of foot posture on all EMG variables

Muscle	Phase of gait cycle	EMG parameter	% mean difference ^	95% CI	Effect size ^#	pvalue (2-tailed)
Tibialis posterior	Contact	TimePeak	0.1	0.0 to 1.7	0.52	0.051
		PeakAmp	-14.3	-29.1 to 0.4	0.51	0.058
		RMS	-7.8	-18.4 to 2.7	0.39	0.144
	Mid/Prop	TimePeak	0.0	-3.8 to 3.7	0.01	0.980
		PeakAmp	26.5*	4.2 to 48.7	0.69	0.021*
		RMS	16.4*	3.6 to 29.1	0.68	0.013*
Peroneus longus	Contact	TimePeak	1.6	0.0 to 3.2	0.51	0.057
		PeakAmp	-12.8*	-25.1 to -0.5	0.48	0.041*
		RMS	-6.6	-13.9 to 0.6	0.48	0.075
	Mid/Prop	TimePeak	3.3	-0.3 to 6.9	0.47	0.079
		PeakAmp	-20.0	-42.9 to 2.9	0.46	0.086
		RMS	-13.7*	-26.1 to -1.4	0.58	0.030*
Tibialis anterior	Contact	TimePeak	0.1	-0.7 to 0.9	0.09	0.737
		PeakAmp	19.0*	11.2 to 26.9	1.3	<0.001*
		RMS	10.4*	4.0 to 16.8	0.87	0.002*
Medial oastrocnemius	Mid/Prop	TimePeak	0.4	-1.8 to 2.7	0.10	0.715
		PeakAmp	2.7	-15.4 to 20.7	0.12	0.766
		RMS	7.2	-12.3 to 16.9	0.22	0.753

Contact -- contact period of gait cycle; Mid/Prop -- combined midstance and propulsion period of gait cycle; TimePeak -- time of peak amplitude; PeakAmp -- peak EMG amplitude; RMS -- root mean square amplitude; ^ relative to normal-arch foot group; CI -- confidence interval;^# Cohen's d calculation;
* statistically significant independent sample t-test (p < 0.05)