14. Adverse events (not death).

Review	Total number of trials (and participants) in review reporting exercise vs control in chronic pain population	Number of trials (and participants) reporting adverse events	Number of adverse events	Overall statement
Bartels 2007	4 (674)	2 (148)	0	Adverse events were recorded (and reported), but none occurred.
Bidonde 2014	9 (519)	0	0	Review stated that no included studies actively reported on adverse events (some reported withdrawal).
Boldt 2014	3 (149)	2 (115)	5 events over 2 studies	"Neck, shoulder and elbow injuries in five participants in the intervention group."
Busch 2007	34 (2276)	6 (strength training: 115, aerobic: 1264)	Strength training: 3 Aerobic training: 5	‐
Busch 2013	3 (81)	2 (86 exercising participants)	0	Adverse events were recorded (and reported), but none occurred.
Cramp 2013	6 (371)	3	0	Adverse events were recorded (and reported), but none occurred.
Fransen 2014	10 (> 549)	5	7 events over 3 studies	‐
Fransen 2015	54 (5362)	11	42 events over 8 studies	‐
Gross 2015a	16 (2485)	11	41 events over 6 studies	‐
Han 2004	3 (206)	2	1 event in 1 study	In narrative: "approximately one‐third of the patients complained of soreness in the knee, shoulder or lower back during the first 3 weeks… pain eventually subsided for all patients… only exception was one patient, who complained of knee pain."
Hayden 2005	43 (3907)	10	23 events over 10 studies	"Negative reported: 16 events over 7 trials."
Hurkmans 2009	5 (575)	2	0	Adverse events were recorded (and reported), but none occurred.
Koopman 2015	2 (68)	1 (10)	0	Adverse events were recorded (and reported), but none occurred. "The study investigated deleterious effects of this training on motor unit survival through motor unit number estimates (MUNE). Results showed that the MUNE did not change at the end of the training."
Lane 2014	30 (1822)	1 (88 exercising participants)	2 events in control group in 1 study	RR 0.20 (95% CI 0.01 to 4.15) in favour of exercise group.
Regnaux 2015	1 (102)	1 (68 exercising participants over 2 groups: low and high resistance)	3 events in 1 study	"3 participants in high resistance group discontinued the exercise intervention due to severe knee pain."
Saragiotto 2016	7 (671)	1 (154)	5 events in 1 study	"Five patients (three from the MCE [motor control exercise] group and two from the minimal intervention group) had mild adverse effects during the study (all temporary exacerbations of pain)."
van der Heijden 2015	10 (1690)	0	0	Of the relevant studies, none actively reported on adverse events.
Yamato 2015	6 (265)	1 (86)	0	Adverse events were recorded (and reported), but none occurred.
Total	246 studies (> 21,772)	61 studies (> 2134 participants)	137 events over 39 studies	61/246 (25%) of studies have reported on adverse events; of which 39/61 (64%) did have adverse events occur as a result of the intervention or control.

n: number of participants; RR: risk ratio.