Table 7 Description of the included systematic reviews; number of original studies included, population, intervention and control. Sling exercises

Yue et al. (2014) [65]

SR: 4

MA: 0

Number of subjects: 706

Definition: NR

Duration > 3 mo

% Women: For those studies that reported it (n = 8); 54%

Age: Mean (SD) 38 (7.4) yrs

Sling exercise (poorly described), 5 of 9 studies involved concomitant therapy (eg. back school, electrotherapy, acupuncture)

Training period:

Mean 5.89 wks, range 1–8 wks, 1–7 sessions/wk, 20–60 min/session

Traditional Chinese medical therapy, other exercise with or without physical factor therapy combined

with drug therapy, thermomagnetic therapies, no treatment

Training period:

Mean 6.33 wks, range 1–12 wks, 1–7 sessions/wk (7–80 sessions in total)

Lee et al. (2014) [66]

SR: 9

MA: 9

Number of subjects: 483

Definition: Chronic low back pain > 12 wks

Duration > 12 wks for studies that reported it (n = 5); Mean (SD) 6.9 (5.6) yrs

% Women: 47.6% (n = 6)

Age: Mean 38.4 yrs

Sling exercise (n = 4), combined with other exercises (n = 2) and combined with other exercises and traction therapy (n = 1)

Training period:

Mean 12 wks, range 1 day-1 year, 1–5 sessions/wk

Other types of exercises (general exercise, motor control exercise) except for one study where controls received manipulation

Training period: Same as intervention

Drummond et al. (2021) [17]

SR: 12

MA: 9

Number of subjects: 631

Definition: Chronic low back pain ≥ 12 wks

Duration

IG: 9.6 mo—9 yrs (min – max)

CG: 9.7 mo—6 yrs (min – max)

for studies that reported it (n = 5);

% Women: 70% (n = 6)

Age: Mean 35.6 yrs

Sling exercise (n = 9), combined with modalities (n = 3)

Training period:

7.64 wks, range 4–12 wks, 1–4 sessions/wk

Other types of exercises (general exercise, motor control training/lumbar stabilization), passive modalities, and control groups that received no treatment

Training period: 7.64 wks, range 4–12 wks, 1–4 sessions/wk