King 2013.

Methods	RCT. "Participants were randomly allocated to a control group (n = 12) or an intervention group (n = 11). One month after T0 data collection, participants were allocated to either study group using simple randomisation with a 1:1 ratio."
Participants	Fifty‐six office workers from a research organisation (the Institute for Work & Health, Ontario, Canada) of 74 employees met the inclusion criteria and were invited to participate in the study. Twenty‐three of the 56 invited agreed to participate. Group 1 (intervention) (n = 11) Group 2 (control) (n = 12)
Interventions	The Hoverstop1 mouse (Vibramouse 2011) provided feedback to the worker by gently vibrating if the worker’s hand had been idle on the mouse for more than 12s. The vibration lasted for a maximum of 4 s. There was no minimum vibration time. The mouse would vibrate until the hand was removed, a mouse button was clicked, the scroll wheel was activated or the maximum vibration time was met (4 s). The feedback was a reminder to rest the arm in neutral postures when not in use. Unlike other break software, the Hoverstop1 does not deliver break messages to the user visually on the monitor. All participants received the alternative mouse with the vibration mechanism turned off during T0 measurements. The vibration mechanism remained turned off in the control group after baseline measurements. All participants received the corresponding Hoverstop1 monitoring software to monitor individual mouse, keyboard and computer activity continuously. All participants were invited to attend a 1‐h study information session with time for questions and answers; attendance was optional. The vibration mechanism was initiated in the intervention group one month after T0 and remained active until the end of the study. The intervention group members were invited to watch a video produced by the manufacturer about the intervention device at their workstation, via a link provided in an email delivered by the research coordinator. The video suggests resting the arm on the desk in front of you when not actively using the mouse, to decrease muscle activation in the shoulder and arm.
Outcomes	T0 Baseline data collection (1 month pre‐activation) Activation: randomisation into intervention and control groups T1 Data collection (5 weeks post activation) T2 Data collection (25 weeks post activation) Pain and discomfort: collected using an online Daily Symptom Survey ‐ Participants were asked to rate their pain at that point in time. The DSS includes a body map with the following areas identified: neck, shoulders, upper back, elbow, lower back, lower arm or wrist or hand, buttock or thighs, knees, lower leg/ankles/feet. Pain and discomfort scores were averaged over the three days of administration for analysis. Mouse use (active hand‐on‐mouse time plus idle hand‐on‐mouse time), Keyboard use (active keyboard time), total computer use (mouse use plus keyboard use), Relative mouse use (RMU: mouse use over the total computer use) were "measured using the Hoverstop ® monitoring software in both the intervention and control groups. An electric‐potential transducer registered when a user’s hand was on or hovered just above the mouse. This feature is believed to give a more accurate measure of exposure to the proposed mechanism of discomfort – static (possibly unsupported) mousing postures – than other collection methods that strictly utilise mouse movements and functions. Keyboard use was measured by the duration of each key compression, while total computer use was determined as the sum of keyboard use and mouse use."
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"A statistician not connected to the study used a random number generator in SAS V. 9.2 to generate the random allocation sequence".
Allocation concealment (selection bias)	Unclear risk	The methods of allocation were not the mentioned.
Blinding of participants and personnel (performance bias) All outcomes	High risk	No blinding of participants: “Participants were not blinded to their groups. Those in the intervention group would have been aware of their group due to the nature of the intervention (the vibrating mouse)”.
Blinding of outcome assessment (detection bias) Musculoskeletal disorders	High risk	The main outcome assessment on the “pain and discomfort collected using an online Daily Symptom Survey administered in the afternoon for three consecutive days at each data collection point: T0, T1 and T2. Participants were asked to rate their pain at that point in time”. The participants themselves rate their pain and discomfort.
Incomplete outcome data (attrition bias) All outcomes	Low risk	“An intention to treat analysis was conducted”, there was also low loss to follow‐up; “There was a low loss to follow‐up (1/23; one participant from the control group), with an additional loss of mouse use data at T2 for two other participants in the control group (see Figure 2 for participant tracking)”.
Selective reporting (reporting bias)	Low risk	No information of selective reporting, all outcomes were reported in the results section.
Other bias	Unclear risk	The demographic data of the participants and the pre‐existing musculoskeletal symptoms of the participants were not collected due to ethical consideration; "Confidentiality and voluntary participation were stressed. Demographics (such as age, gender, job type and preexisting symptoms) were not collected due to ethical considerations, since the study was executed within our research institute." The successful randomisation of the participants was not able to be ascertain due to this reason.