Table 2 Characteristics of the included studies in chronological order

Ge et al. [49]

BMC Geriatrics

China

20 female patients with non-specific LBP for ≥ 3 months in the previous year, age ≥ 60 years (mean = 64.90 ± 3.33 y) and 20 healthy participants, age ≥ 60 years (mean = 63.20 ± 2.33 y)

TecnoBody system (PK254P; TecnoBody, Italy). All the center of pressure signals were sampled at a rate of 100 Hz and filtered at 8 Hz (by a 30th order low-pass FIR filter with zero-phase) and down-sampled at 20 Hz

Three postural tasks: (1) rigid-surface with eyes open, (2) rigid-surface with eyes closed, and (3) single leg stance

Data from tasks (1) and (3) were used for meta-analysis

Cognitive tasks: (1) no cognitive task, (2) auditory arithmetic task, and (3) serial-7s arithmetic task

Data from ‘serial-7s arithmetic’ task were used for meta-analysis

Mental tracking/working memory tasks

Center of pressure parameters including sway area, sway length, AP velocity, and MD velocity

Shanbezadeh et al. [29]

Experimental Brain Research

Iran

38 patients with non-specific chronic LBP (19 with low and 19 with high pain-related anxiety levels) (mean age = 28.61 ± 1.33 y) and 20 asymptomatic participants (mean age = 28.32 ± 6.11 y)

Force platform (Bertec Corp, Columbus, OH, USA). Data were sampled at 500 Hz, and low-pass filtered with a cut-off frequency of 10 Hz

Four postural tasks: Eyes open with and without ankle vibration, eyes closed with and without ankle vibrations

Data from ‘eyes open without ankle vibration’ and ‘eyes closed with ankle vibrations’ tasks were used for meta-analysis

Cognitive tasks: (1) no auditory Stroop task, and (2) auditory Stroop task

Data from ‘auditory Stroop task’ task were used for meta-analysis

Discrimination and decision-making tasks

Center of pressure parameters including area, velocity, AP range, and MD range; and reaction time, and error ratio of auditory Stroop test

Etemadi et al. [15]

Gait and Posture

Iran

20 patients with recurrent non-specific LBP (10 male, 10 female; mean age = 31.68 ± 8.63 y) and 20 asymptomatic participants (11 male, 9 female; mean age = 30.95 ± 8.08 y)

Force platform (Equitest, Neurocom Int. Inc., Clackamas,

Oregon, USA). Data were recorded with a sampling rate of 500 Hz

Four postural tasks: (1) forward medium perturbation while standing, (2) forward large perturbation while standing, (3) backward medium perturbation while standing, and (4) backward large perturbation while standing

Data from ‘forward medium perturbation while standing’ and ‘backward large perturbation while standing’ tasks were used for meta-analysis

Cognitive tasks: (1) no auditory Stroop task, and (2) auditory Stroop task

Data from ‘auditory Stroop task’ task were used for meta-analysis

Discrimination and decision-making tasks

Center of pressure parameters including amplitude, velocity, reaction time, latency, and reaction time for cognitive performance

Mazaheri et al. [11]

Spine

Iran

20 patients with current non-specific LBP (12 male, 8 female; mean age = 33.5 ± 9.2 y), 20 patients with recent non-specific LBP (12 male, 8 female; mean age = 35.3 ± 10.2 y), and 20 asymptomatic participants (12 male, 8 female; mean age = 34.3 ± 7.6 y)

A portable Kistler force platform (500 × 600 mm, type 9260 AA; Kistler Instruments, Winterthur, Switzerland). Data were sampled at a rate of 100 samples/second producing a total of 6000 COP data points for a recording of 60 s

Two postural tasks: (1) wide base of support, and (2) narrow base of support

Cognitive tasks: (1) no color-number classification task, and (2) color-number classification task

Data from ‘color-number classification’ task were used for meta-analysis

Discrimination and decision-making tasks

Center of pressure parameters including sway amplitude, path length, mean power frequency, and sample entropy

Salavati et al. [14]

Spine

Iran

22 patients with non-specific LBP (13 male, 9 female; mean age = 26.1 ± 6.2 y), and 22 asymptomatic participants (13 male, 9 female; mean age = 25 ± 5.5 y)

A strain gauge Bertec 4060–10 force platform and Bertec AM-6701 amplifier (Bertec Corp., Columbus, OH). Data were sampled at 200 Hz

Three postural tasks: (1) rigid-surface with eyes open, (2) rigid-surface with eyes closed, and (3) foam-surface with eyes closed

Data from ‘rigid-surface with eyes open’ and ‘foam-surface with eyes closed’ tasks were used for meta-analysis

Cognitive tasks: (1) easy task, and (2) difficult digits backward task

Data from ‘difficult digits backward’ task were used for meta-analysis

Mental tracking/working memory tasks

Center of pressure parameters including velocity, phase plane portrait, and standard deviation of velocity