@Article{Çabuk2026,
journal="Biology of Sport",
issn="0860-021X",
volume="43",
number="1",
year="2026",
title="Can OpenCap deliver valid and reliable kinematic data for motion analysis? A systematic review and three-level meta-analysis",
abstract="Markerless motion capture systems have gained increasing interest as practical alternatives to gold-standard references systems in clinical and sports contexts. This systematic review and three-level metaanalysis aimed to evaluate the criterion validity of OpenCap and to systematically summarize the available evidence	regarding	its	reliability.	A literature	search	was	conducted	across	Web	of	Science,	PubMed,	Scopus,	and	EBSCO.	Among	the	12 studies	included	in	the	systematic	review,	11 provided	sufficient	data	for	the	meta analytic	synthesis	of	criterion	validity,	encompassing	184 participants,	from	which	640 effect	sizes	(ES),	230 Fisher’s	Z values,	and	1087 root	mean	square	error	(RMSE)	values	were	obtained.	OpenCap	demonstrated	a statistically	significant,	yet	practically	trivial	effect	compared	to	criterion	devices	(ES =	-0.140;	p =	0.021).	Fisher’s	Z transformation	indicated	a good-to-excellent	correlation	with	criterion	devices	(r =	0.845;	p =	0.005).	The	pooled	RMSE	was	5.877°,	which	decreased	to	5.197°	after	sensitivity	analysis	and	further	to	4.940°	following	trim-and-fill	adjustment.	In	terms	of	reliability,	test-retest	consistency	generally	ranged	from	moderate	to	very	good	across	many	joint	angles	and	tasks,	although	marked	variability	was	observed	in	certain	task-joint combinations,	particularly	in	high-velocity	movements	and	complex	joint	actions.	OpenCap,	as	a smartphone based markerless motion capture system, can provide valid and acceptable kinematic measurements when compared	to	criterion	devices.	However,	its	performance	varies	depending	on	task	complexity	and	joint-specific	demands,	underscoring	the	need	for	evaluation	across	diverse	populations,	a wider	range	of	task	types,	and	within standardized methodological frameworks.",
author="Çabuk, Salih
and Ulupınar, Süleyman
and İnce, İzzet
and Özbay, Serhat",
pages="555--573",
doi="10.5114/biolsport.2026.154942",
url="http://dx.doi.org/10.5114/biolsport.2026.154942"
}