Table 10. A summary of dynamic surface EMG data collection, recording and signal processing.

EMG recording and signal processing for therapeutic studies.

	PREPARATION/RECORDING		SIGNAL PROCESSING				RESULTS
Study	Muscles [Preparation Described]	Recording Device [Sampling Frequency]	Filter Passband [Stim artefact filtration]	Rectification	Cycle averaging	Amplitude Normalization	Output Presented
Hofstoetter et al., 2013 [6]	Q, Ham, TA, TS	Wired EMS Handels system	10–500 Hz	Raw EMG	-	-	Exemplary raw EMG traces during stepping. Qualitative comparison of stim on/off
	[✓]	[2048Hz]	[✗]
Gerasimenko et al., 2015 [67]	Sol, MG, TA, med ham, VL	Wired A/D board and customized labVIEW software	10–10,000Hz	-	-	-	Exemplary raw EMG during voluntary movement. Scatter-plot of antagonistic muscle activity patterns. Qualitative description of EMG change during stim.
	[✗]	[10,000Hz]	[✓]
Hofstoetter et al., 2015 [18]	Q, Ham, TA, TS	EMS-Handels system	10–500 Hz	RMS	10 gait cycles	EMG during stance and swing phase normalized to muscle activity with stim off	Exemplary raw EMG during stepping. Radar chart of RMS during stance and swing. Qualitative comparison of stim on/off
	[✓]	[2048Hz]	[✓]
Bedi, 2016 [68]	Q, Ham, TA, TP	Neurostim Medicad System	10–500 Hz	RMS	3 repetitions per side	-	Tables of RMS data during voluntary movement before and after stim
	[✓]	[NS]	[✗]
Minassian et al., 2016 [19]	Q, Ham, TA, TS, TFL	Wired Poly-EMG system (EMS-Handels)	20–500 Hz	RMS	10 gait cycles	-	Within subject quantitative comparison (ANOVA) of RMS data for treadmill speed x hip extension. Exemplary raw EMG during stepping and standing.
	[✓]	[2048Hz]	[✓]
Gad et al., 2017 [41]	Sol, MG, TA, med ham, VL	Wired Powerlab and LabChart. Delsys EMG System also mentioned.	10–1000 Hz	Integrated	30 steps	-	Exemplary raw EMG and iEMG during stepping and voluntary movement. Exemplary evoked responses. Qualitative comparison of EMG during passive and active stepping during the intervention.
	[✓]	[10,000Hz]	[✓]		5 evoked responses
Freyvert et al,. 2018 [44]	FD, ED, BR, BB, TB	Konigsberg EMG system	-	-	9 x 3.5 sec hand-grip Repetition	-	Quantitative comparison of raw EMG amplitude across each test phase Exemplary raw EMG during voluntary hand grip tasks.
	[✗]	[NS]	[✗]
Rath et al., 2018 [37]	RA, Obl, E-T7, E-L3, RF, delt	Wired Powerlab 16/35	10–2000 Hz	Full wave rectification	-	-	Exemplary rectified EMG during trunk movement. Quantitative comparison of mean EMG with stim on/off.
	[✗]	[2000Hz]	[✓]
Gad et al., 2018 [43]	BB, FD, ED	Wired Powerlab	10–10,000Hz, 60Hz Notch	Integrated	5 evoked responses per intensity	Evoked responses normalized to baseline.	Exemplary raw and iEMG of evoked responses. Exemplary raw EMG traces during voluntary contractions. Quantitative comparison of iEMG response to stim on/off and pre- post-intervention
	[✗]	[10,000Hz]	[✗]
Inanici et al., 2018 [36]	Delt, TB, BB, BR, ED, FD, ADM, thenar muscles	Wired Delsys Bagnoli system	-	Raw EMG	-	-	Examplary trace of evoked response in thenar muscles compared every 2 weeks across intervention.
	[✗]	[1000Hz]	[✗]
Sayenko et al., 2019 [42]	Sol, TA, VL, med ham	Wired Powerlab	10–2000 Hz	Full wave rectification and RMS	6 evoked responses	EMG during anterior/posterior weight shift normalized to activity during initial position	Exemplary raw EMG during transition and standing. Quantitative comparison of mean EMG between stim on/off, sitting and standing and Quantitative comparison of RMS EMG and motor thresholds across training sessions.
	[✗]	[4000Hz]	[✓]
Al’Joboori et al., 2020 [69]	Q, TA, ham, gastric	Wired CED Power 1401	10–200 Hz	RMS (0.4s window). Integrated to average level of rectified signal.	3 trials with flex/ext phases	-	Intergrated EMG activity pre and post trial temporally normalized to phase of movement
	[✗]	[2000Hz]	[✗]
Alam et al., 2020 [40]	Q, TA, ham, gastric	Wireless, BTS Telemg	[✗]	P2P amplitude of MEPs.	-	-	Exemplary raw EMG during sit-to-stand and stand-to-sit task. Intensity response curves for each muscle.
	[✗]	[2000Hz]
Meyer et al. 2020 [70]	1) RF, VM, ST, TA, MG	1) Wireless Aktos System	1) 10–500 Hz	Noise corrected RMS	1) 20 cycles of each rep ankle movements	Tonic stim responses normalized to the respective values in the tSCS-off condition using z-scores	Exemplary data comparing stim off vs. on - 15Hz/30Hz/50Hz
		[2000Hz]	2) 20 Hz—3000 Hz				normalized RMS stim off vs. on - 15Hz/30Hz/50Hz
	2) Spinal reflex protocol: bilateral TA	2) Dantec Keypoint Focus Workstation	[✓]		2) 5 spinal reflexes		phase of gait muscle activity
	[✗]	[6000Hz]
Shapkova et al., 2020 [38]	RF, BF, GL, TA	Viasys Viking Select	-	-	-	-	Exemplary trace of H-Reflex and MMR reseponse.
	[✗]	[2000Hz]	[✗]
Zhang et al., 2020 [71]	Trap, delt, BB, TB, BR, ECU, FCR, ECR	Wired MA-400 Motion Lab Systems	10–1000 Hz 60Hz Notch	Integrated	3 evoked responses	-	Evoked potential amplitudes pre- and post-stimulation intervention
	[✗]	[10200 Hz]	[✗]

Abbreviations: BB; biceps brachii, BR; brachioradialis, delt; deltoid, ED; extensor digitorum, E-L3; erector spinae at level of L3, EMG; electromyography, E-T7; erector spinae at level of T7, ECU; extensor carpi ulnaris, ECR; extensor carpi radialis, FCU; flexor carpi ulnaris, FD; flexor digitorum, Ham; hamstrings, iEMG; integrated EMG, med ham; medial hamstrings, MG; medial gastrocnemius, obl; external oblique, P2P; peak-to-peak, PL; Peroneus Longus, Q; quadriceps, RA; rectus abdominis, RF; rectus femoris, RMS; root mean square, sol; soleus, ST; semitendinosus, TA; Tibialis Anterior, TB; triceps brachii, TFL; tensor fascia lata, TP; tibialis posterior, Trap; trapezius, TB; triceps brachii, TS; triceps surae, VL; vastus lateralis.

* Recording electrodes described refers to a clear description of preparation of the skin before surface electrode application, recording electrode type, orientation, shape and composition as well as interelectrode distance.

† Artifact filtering refers to an attempt made by the authors to account for and remove artifacts contaminating or obscuring the recorded EMG signals such as with the use of a filter or reference EMG electrodes for artefact cancellation.