Effects of the head lift exercise and neuromuscular electrical stimulation on swallowing muscles activity in healthy older adults: a randomized pilot study

Figures & data

Figure 1 Placement of electrodes used for NMES application.

Abbreviation: NMES, neuromuscular electrical stimulation.

Figure 2 Placement of sEMG electrodes on the supra- and infrahyoid muscles.

Abbreviation: sEMG, surface electromyography.

Figure 3 (A) Raw EMG signal of the suprahyoid muscles (above trace) and the infrahyoid muscles (below trace) during swallowing. (B) The rectified EMG signals of the suprahyoid muscles (above trace) and the infrahyoid muscles (below trace). Abbreviation: EMG, electromyographic.

Figure 4 Subject dropout.

Abbreviations: HLE, head lift exercise; NMES, neuromuscular electrical stimulation.

Table 1 The mean ± standard deviation of sEMG parameters of the suprahyoid muscle activity before and after treatment

Measure		HLE			NMES
		n*	Mean	SD	n	Mean	SD
Mean amplitude of sEMG activity (µv)	Pre- treatment	9	4.86	1.53	10	5.58	2.22
	Post-treatment	9	5.15	2.52	10	6.01	2.74
Duration of sEMG activity (seconds)	Pre- treatment	9	4.81	0.91	10	5.13	1.41
	Post-treatment	9	4.05	0.51	10	5.57	1.43
Latency between the onset and the peak amplitude of sEMG activity (seconds)	Pre- treatment	9	3.10	1.09	10	3.34	1.66
	Post-treatment	9	2.50	0.50	10	3.98	1.21

Note: *N=9 due to weak quality of sEMG signal in one subject.

Abbreviations: HLE, head lift exercise; NMES, neuromuscular electrical stimulation; sEMG, surface electromyography.

Table 2 The Mean±standard deviation of sEMG parameters of the infrahyoid muscle activity before and after treatment

Measure		HLE			NMES
		n	Mean	SD	n*	Mean	SD
Mean amplitude of sEMG activity (µv)	Pre-treatment	10	3.30	1.14	9	3.47	1.62
	Post-treatment	10	3.79	1.64	9	3.53	1.39
Duration of sEMG activity (seconds)	Pre-treatment	10	5.06	1.34	9	4.60	2.02
	Post-treatment	10	4.33	1.38	9	4.99	2.04
Latency between the onset and the peak amplitude of sEMG activity (seconds)	Pre-treatment	10	3.19	0.62	9	3.40	1.97
	Post-treatment	10	2.73	0.73	9	3.44	1.22

Notes: *N=9 due to weak quality of sEMG signal in one subject

Abbreviations: HLE, head lift exercise; NMES, neuromuscular electrical stimulation; sEMG, surface electromyography.