Table 2.

List of muscular activity biomarkers having at least 3 COSMIN items assessed in the included studies. Biomarkers for which all these items reached at least a good level (see Table 4 for measurement properties rating) are in bold.

ID	Variable name	Task	Reliability		Validity			Interpr	Clinical appl	Study
			R1	R2	V1	V2	V3	MDC
BMu42	Erector spinae (longissimus) EMG signal (max) flexion/maximal flexion ratio	Trunk sagittal bending	NA/+++	NA	++	NA	++	NA	++	Neblett et al., 201337; Watson et al., 199738
BMu77	Rectus abdominis activation onset latency	Two-legged standing	++/++	NA	++	NA	++	NA	++	Jacobs et al., 201664; Liebetrau et al., 201333; Mehta et al., 201032
BMu78	External oblique activation onset latency	Two-legged standing	++/++	NA	++	NA	++	NA	++	Jacobs et al., 201664; Mehta et al., 201032
BMu80	Internal oblique activation onset latency	Two-legged standing	++/++	NA	+++	NA	++	NA	++	Liebetrau et al., 201333; Mehta et al., 201032; Osuka et al., 201965
BMu83	Internal oblique/multifidus cocontraction duration	Two-legged standing	++/++	NA	+++	NA	+	NA	++	Mehta et al., 201032
BMu84	Internal oblique activation burst duration	Two-legged standing	++/++	NA	+++	NA	++	NA	++	Mehta et al., 201032
BMu85	Transversus abdominis activation burst duration	Two-legged standing	++/++	NA	+++	NA	++	NA	++	Mehta et al., 201032
BMu86	External oblique activation burst duration	Two-legged standing	++/++	NA	+++	NA	++	NA	++	Mehta et al., 201032
BMu87	Rectus abdominis activation burst duration	Two-legged standing	++/++	NA	+++	NA	++	NA	++	Mehta et al., 201032
BMu88	Multifidus activation burst duration	Two-legged standing	++/++	NA	+++	NA	+	NA	++	Mehta et al., 201032
BMu89	Transversus abdominis activation onset latency	Two-legged standing	++/++	NA	+++	NA	++	NA	++	Mehta et al., 201032
BMu90	Multifidus activation onset latency	Two-legged standing	++/++	NA	+++	NA	+++	NA	++	Mehta et al., 201032
BMu92	Rectus abdominis preprogrammed reaction amplitude	Two-legged standing	NA	+++/+++	++	NA	+	NA	+	Ramprasad et al., 201066
BMu93	Erector spinae (longissimus) preprogrammed reaction amplitude	Two-legged standing	NA	+++/+++	++	NA	+	NA	+	Ramprasad et al., 201066

R1: Intra-observer reliability (controls/patients); R2: Inter-observer reliability (controls/patients); V1: Content validity; V2: Criterion validity; V3: Construct validity.

max: maximum, MDC: minimum detectable change, interp.: interpretability, appl.: applicability, in bold: biomarkers for which all items reached at least a good level (see Table 1 for measurement properties rating).

+++: Excellent; ++: Good; +: Moderate; ●: available; NA: not available (see Table 4 for measurement properties rating).