Effects of respiratory muscle training on post-stroke rehabilitation: A systematic review and meta-analysis

Table 1 Characteristics of studies included in the meta-analysis

Ref.	Intervention (experimental group)	Intervention (control group)	Pulmonary function	Respiratory muscle strength	Exercise tolerance
Kim et al[17] (2015)	Received routine therapy and RMT using incentive respiratory spirometer for 15 min a day, five times a week for 6 wk	All of the subjects received routine therapy for stroke rehabilitation for 1 h, five times a week for 6 wk	FVC, FEV1	NA	NA
Wei et al[13] (2022)	The experimental group received a Breathe-Link trainer based on regular training, with rehabilitation training for 12 wk as the time node	One group was set as the control group and received routine breathing training	FVC, FEV1, FEV1/FVC	NA	NA
Choi et al[11] (2021)	The RMT program was conducted daily 5 times/wk for 1 mo. Each exercise session lasted 30 min	The standard rehabilitation (SR) group (patients who did not undergo RMT)	MVV, FVC, FEV1, PEF	MIP, MEP	NA
Cho et al[25] (2018)	The experimental group underwent inspiratory muscle training with resistance adjusted to 30% of maximal inspiratory pressure, 90 breaths a day, 5 times a week for 6 wk	Both groups received regular physical therapy for the same amount of time	NA	MIP	6MWT
Kim et al[16] (2014)	The exercise group performed the same exercise regimen as the control group, as well as an additional respiratory muscle training regimen using a respiratory exercise device for 20 min	The control group received basic exercise treatments for 30 min, followed by an automated full-body workout for 20 min	FVC, FEV1, FEV1/FVC, PEF	NA	6MWT
Parreiras de Menezes et al[18] (2018)	The experimental group received 40-min high-intensity home-based respiratory muscle training, 7 d per week, for 8 wk, progressed weekly	The control group received a sham intervention of similar dose	NA	MIP, MEP	6WMT
Lee et al[21] (2018)	Both forced expiratory/inspiratory muscle training were repeated 10-15 times, 5 set for 20 min in a session and a resting time of 30-60 s between each set	All patients received conventional physical and occupational therapy conducted for 30 min, 2 times a day, and 6 times per week, but no RMT or TSE	PEF, FEV1, VC	MIP, MEP	NA
Jung et al[12] (2017)	Patients in the experimental group received inspiratory muscle training for 30 min (six sets of 5-min) and traditional physical therapy once a day, 5 d a week, for 4 wk	The control group received aerobic exercise for 30 min and traditional physical therapy for 30 min a day, 5 d a week, for 4 wk	FVC, FEV1	NA	10MWT, 6MWT
Vaz et al[15] (2021)	The experimental group (EG) (n = 23) underwent IMT for 30 min/d, five times/wk over 6 wk	The control group (CG) (n = 27) performed sham IMT	NA	MIP, MEP	6MWT
Liaw et al[23] (2020)	Expiration training pressure commenced from 15% to 75% of threshold load of an individual’s MEP for 5 sets of 5 repetitions, 1 to 2 times per day, 5 d a week for 6 wk; 1 to 2 min of rest was allowed between each set	Usual rehabilitation program	FVC, FEV1, FEV1/FVC, MMEF	MIP, MEP	NA
Chen et al[19] (2016)	Patients in the IMT group received an additional IMT program beginning with an intensity of 30% maximal inspiratory pressure (MIP), then increased by 2 cmH2O each week for 30 min daily for at least 5 d a week for 10 wk	Participated in a conventional stroke rehabilitation program	FVC, FEV1, FEV1/FVC	MIP, MEP	NA
Britto et al[20] (2011)	Interventions were based on home-based training, with resistance adjusted biweekly to 30% of MIP for the experimental group	The control group underwent the same protocol without the threshold resistance valve. Both groups received home training 30 min a day 5 times a week for 8 wk	NA	MIP	NA
Aydoğan Arslan et al[14] (2021)	The patient was asked to work-out 15 min in 2 sessions (30 min per day), 7 d a week. IMT was performed 5 d a week in 1 session with the help of a physiotherapist	Received routine breathing training	FVC, FEV1, PEF, FEV1/FVC	MIP, MEP	6MWT
Sutbeyaz et al[22] (2008)	The subjects started breathing at a load of 40% of the maximum inspiratory pressure (PImax). Exercise intensity was gradually increased, 5%–10% each session, to 60% of PImax as tolerated. All patients trained daily for two sessions of 15 min each, six times a week for 6 wk	Both the training groups and the control group participated in a conventional stroke rehabilitation programme, 5 d a week for 6 wk	FEV1, FVC, VC, PEF, MVV	MIP, MEP	NA
Joo et al[24] (2015)	The GBE group participated in a GBE program for 25 min a day, 3 d a week, during a 5-wk period	Both groups participated in a conventional stroke rehabilitation program	FVC, FEV1, FEV1/FVC, MVV	NA	NA

NA: Not available; FVC: Forced vital capacity; FEV1: Forced expiratory volume in the first second; FEV1/FVC: Ratio of forced expiratory volume in the first second to forced vital capacity; PEF: Peak expiratory flow; MIP: Maximal inspiratory pressure; MEP: Maximal expiratory pressure; MWT: Minute walk test.