Introduction
Methods
Search strategy
Eligibility criteria
Study selection
Quality assessment
Results
Study identification
Characteristics of included studies
Study | Participants LBP Group | Participants control group | Type of LBP | Duration of LBP | Presence of LBP at Baseline | Gluteus medius measurement outcome |
---|---|---|---|---|---|---|
Aboufazeli et al. 2018 [39] Iran. | n = 30 Mean age, years (SD): 34.6 (6.2) Population: Not reported Gender: 100%F BMI (SD): 23.4 (3.2) | n = 30 Mean age, years (SD): 36.7 (6.7) Population: Note reported Gender: 100%F BMI (SD): 23.6 (3.3) | Nonspecific LBP | ≥3 months | Yes | Muscle thickness |
Arab & Nourbakhsh 2010 [4] Iran | n = 100 Mean age, years (SD): 42.58 (14.1) Population: Patients of orthopaedic department Gender: Not Reported BMI (SD): 25.03 (3.0) | n = 100 Mean age, years (SD): 43.40 (4.41) Population: Patients of orthopaedic department Gender: Not Reported BMI (SD): 25.68 (4.1) | Not Reported | > 6 weeks | Yes | Strength |
Cai & Kong 2015 [23] Singapore | n = 18 Mean age, years (SD): 27.80 (NR) Population: Recreational Runners Gender: 50%F BMI (SD): 21.75 (NR) | n = 18 Mean age, years (SD): 24.60 (NR) Population: Recreational Runners Gender: 50%F BMI (SD): 21.40 (NR) | Not Reported | > 3 months, but less than 36 months | Yes | Strength |
Cooper et al. 2016 [16] USA | n = 150 Mean age, years (SD): 41.40 (13.0) Population: Patients at Iowa Spine Centre Physical Therapy Clinic Gender: 64.70%F BMI (SD): 29.60 (7.2) | n = 75 Mean age, years (SD): 40.70 (13.9) Population: Patients at Iowa Spine Centre Physical Therapy Clinic Gender: 64.30%F BMI (SD): 25.80 (7.0) | Nonspecific LBP | > 3 months | Yes – Only one participant reported no current LBP | Strength and trigger points |
Embaby & Abdallah 2013 [24] Egypt | n = 15 Mean age, years (SD): 29.53 (2.4) Population Clinical Instructors Gender: 100%F BMI (SD): 24.01 (NR) | n = 15 Mean age, years (SD): 29.07 (2.4) Population: Clinical Instructors Gender: 100%F BMI (SD): 22.63 (NR) | Nonspecific | Periods of mild or moderate LBP for > 6 months | Not Reported | Fatigability |
Farahpour et al. 2018 [17] Iran | n = 15 Mean age, years (SD): 25.30 (2.9) Population: Patients from a ‘clinic’ Gender:0%F BMI (SD): 26.80 (1.5) | n = 15 Mean age, years (SD): 26.00 (2.9) Population: Not reported Gender: 0%F BMI (SD): 25.90 (3.2) | Not reported | Not reported | Yes | Activity level |
Farasyn & Meeusen 2005 [35] Belgium | n = 87 Mean age, years (SD): 43.00 (13.0) Population: Physiotherapy patients Gender: 55.17%F BMI (SD): 20.50 (2.8) | n = 64 Mean age, years (SD): 40.00 (11.0) Population: Physiotherapy patients Gender: 62.50%F BMI (SD): 21.50 (3.2) | Nonspecific LBP | Subacute nonspecific lower back pain | Yes | Trigger points |
Hides et al. 2016 [25] Australia | As a whole group LBP n = 7, no LBP n = 18 Mean age, years (SD): 24.40 (5.5) Population: Elite Footballers Gender: 0%F BMI (SD): 23.61 (NR) | Not Reported | Not reported | Not reported | Strength | |
Hungerford et al. 2003 [26] Australia | n = 14 Mean age, years (SD): 32.70 (NR) Population: Men with SIJP Gender: 0%F BMI (SD): 24.63 (NR) | n = 14 Mean age, years (SD): 33.50 (NR) Population: without SIJP Gender: 0%F BMI (SD):23.40 (NR) | SIJP | > 2 months | Yes | Activity level and time to onset |
Iglesias-Gonzalez et al. 2013 [27] Spain | n = 42 Mean age, years (SD): 45.00 (10.0) Population: Patients of a private physical therapy clinic Gender: 50.00%F BMI (SD):24.50 (3.2) | n = 42 Mean age, years (SD): 45.00 (9.0) Population: Subjects who responded to local advertisements Gender: 50.00%F BMI (SD): 24.90 (3.4) | Nonspecific LBP | > 3 years | Yes | Trigger points |
Kendall et al. 2010 [5] Canada | n = 10 Mean age, years (SD): 32.00 (NR) Population: Not Stated Gender: 80.00%F BMI (SD): 20.86 (NR) | n = 10 Mean age, years (SD): 26.00 (NR) Population: Not Stated Gender: 80.00%F BMI (SD): 21.61 (NR) | Nonspecific LBP | > 6 weeks | Yes | Strength |
Larsen et al. 2018 [38] Denmark | n = 27 Mean age, years (SD): 27.40 (9.9) Population: University campus and hospital Gender: 44.44 BMI (SD): 21.90 (3.2) | n = 26 Mean age, years (SD): 23.60 (4.4) Population: University campus and hospital Gender: 61.53%F BMI (SD): 23.80 (2.5) | Nonspecific | > 3 years | No | Activity level |
Mendis et al. 2016 [37] Australia | As a whole group LBP n = 13, no LBP n = 33 Mean age, years (SD): 22.80 (3.5) Population: Australian Elite AFL Players Gender: 0%F BMI (SD): 25.00 (NR) | Not Reported | Not Reported | Yes | Cross-sectional area | |
Nelson-Wong et al. 2013 [6] USA | n = 17 Mean age, years (SD): 27.71 (10.6) Population: general population Gender: not reported BMI (SD): 23.42 (2.9) | n = 17 Mean age, years (SD): 28.52 (10.2) Population: general population Gender: not reported BMI (SD): 22.99 (1.8) | Not Reported | Not Reported | Yes | Time to onset |
Njoo & Van der Does 1994 [36] Netherlands | n = 61 Mean age, years (SD): 36.20 (9.8) Population: Patients of participating health care centres Gender: 44.20%F BMI (SD): Not Reported | n = 61 Mean age, years (SD): 38.10 (9.9) Population: Every 10th patients of health care centres without LBP Gender: 50.70%F BMI (SD): Not Reported | Nonspecific LBP | Recent episode of less than 2 months | No | Trigger points |
Notzel et al. 2011 [28] Germany | n = 8 Mean age, years (SD): 42.40 (14.5) Population: Not Reported Gender: 100%F BMI (SD): 23.10 (2.4) | n = 12 Mean age, years (SD): 27.30 (7.1) Population: Not Reported Gender: 100%F BMI (SD): 20.40 (2.6) | Nonspecific LBP | > 6 months several times per week or daily | Not Reported | Activity level |
Nourbakhsh & Arab 2002 [3] Iran | n = 300 Mean age, years (SD): 43.00 (NR) Population: Hospital inpatients Gender: 50.00%F BMI (SD): 25.76 (NR) | n = 300 Mean age, years (SD): 43.00 (NR) Population: Hospital inpatients Gender: 50.00%F BMI (SD): 24.44 (NR) | Not Reported | > 6 weeks | Yes | Strength |
Penney et al. 2014 [29] Canada | n = 21 Mean age, years (SD): 46.00 (15.2) Population: Patients at local physiotherapy clinics Gender: 42.85%F BMI (SD): 27.40 (NR) | n = 22 Mean age, years (SD): 44.00 (15.5) Population: University and Hospital Community Gender: 33.36%F BMI (SD): 26.95 (NR) | Nonspecific LBP | > 12 weeks | Yes | Activity level, time to onset, and strength |
Rabel et al. 2013 [30] USA | n = 12 Mean age, years (SD): 44.40 (14.6) Population: Physiotherapy patients Gender: 58.33%F BMI (SD): 29.70 (10.3) | n = 22 Mean age, years (SD): 27.20 (4.6) Population: Recreationally active Gender: 50.00%F BMI (SD): 24.70 (4.9) | Not Reported | < 2 months and > 3/10 on VAS | Yes | Time to onset |
Ringheim et al. 2015 [31] Norway | n = 17 Mean age, years (SD):39.00 (5.4) Population: Hospital outpatients Gender: 58.82%F BMI (SD): 25.90 (4.7) | n = 20 Mean age, years (SD): 40.20 (5.4) Population: Not Reported Gender: 61.90%F BMI (SD): 25.20 (3.7) | Nonspecific | > 3 months | Yes | Activity level and fatigability |
Santos et al. 2013 [18] Brazil | n = 29 Mean age, years (SD): 45.80 (14.3) Population: Orthopaedic patients Gender: 100%F BMI (SD): 24.15 (3.9) | n = 30 Mean age, years (SD): 44.57 (13.6) Population: Not Reported Gender: 100%F BMI (SD): 23.77 (2.1) | Nonspecific LBP | > 3 months | No | Activity level and time of peak |
Skorupska et al. 2016 [32] Poland | n = 71 Mean age, years (SD): 47.70 (8.4) Population: Not reported Gender: 61.97%F BMI (SD): Not Reported | n = 29 Mean age, years (SD): 47.60 (9.9) Population: Not reported Gender: 65.51%F BMI (SD): Not Reported | Not Reported | Subacute or Chronic | Yes | Cross-sectional area |
Sutherlin & Hart 2015a [33] USA | n = 12 Mean age, years (SD): 24.00 (4.0) Population: Not Reported Gender: Not Reported %F BMI (SD): 25.19 (3.4) | n = 12 Mean age, years (SD): 22.00 (3.0) Population: Not Reported Gender: Not Reported %F BMI (SD): 21.28 (2.4) | Not Reported | Not reported | Yes | Strength |
Sutherlin & Hart 2015b [34] USA | n = 12 Mean age, years (SD): 24.00 (4.0) Population: Not Reported Gender: 58.33%F BMI (SD): 25.19 (3.4) | n = 12 Mean age, years (SD): 22.0 (3.0) Population: Not Reported Gender: 75.00%F BMI (SD): 21.28 (2.4) | Not Reported | Not reported | Yes | Activity level and fatigability |
Included studies by measurement outcome
Level of muscle activity (EMG)
Study | Measurement equipment | Method | Result | Major Conclusions | |||
---|---|---|---|---|---|---|---|
Notzel et al. 2011 [28] | Modified Posturomed, Biovision | Participants stood barefoot in a static weight bearing position on the posturomed plate for 10 s while it that vibrated. | Activity level | Fatigability | Time to onset | Time of peak | Patients with LBP demonstrated statistically significant less gluteus medius muscle activity compared to controls. This could be associated with reduced hip stability. |
LBP: 56.29 μV (±39.63) nLBP: 96.42 μV (±64.77), p < .05 Normalisation: not performed, raw EMG values used | Not measured | Not measured | Not measured | ||||
Farahpour et al. 2018 [17] | BTS FREE EMG300 | Participants walked for 8 steps in standardised shoes. | RMS LBP: 111.8% (±48.6%) nLBP: 48.4% (±27.3%), p < .05 Normalisation: % of MVIC in single leg stance while maintaining the pelvis level | Not measured | Not measured | Not measured | Participants with LBP showed statistically significant more gluteus medius muscle activity compared to controls. |
Larsen et al. 2018 [38] | Noraxon EMG | Participants performed 10 ascent and 10 descent step tasks at self-selected speed, separated by 3 min of rest. | RMS Specific values not reported, p > .05 Normalisation: % of sub maximum voluntary contraction during standing hip abduction with manual external resistance | Not measured | Not measured | Not measured | No statistically significant differences in gluteus medius activity during ascent and descent between those with and without LBP. |
Penney et al. 2014 [29] | Biopac EMG system | Participants stood in a single leg stance position for 30 s, with the non-weight bearing limb flexed between 60 and 90 degrees at the hip. One minute rest between each of the 3 reps per side, with a 5 min rest between sides. | RMS LBP: 5.8% (± 2.6%) nLBP: 4.2% (± 2.3%), p = .05 iEMG LBP: 122% (± 55%) nLBP: 87.8% (± 49%), p = .03 Normalisation: % of MVIC in side-lying hip abduction with manual resistance | Not measured | LBP: 461.7 ms (±286.5) nLBP: 493.4 ms (±292.8), p = .73 | Not measured | There was no statistically significant difference in onset time of the gluteus medius when moving to unipedal stance between the groups. However, the LBP group demonstrated statistically significant more gluteus medius activation. |
Santos et al. 2013 [18] | EMG810C, EMG System do Brasil® | Participants started kneeling and then were asked to flex their R hip and extend their R knee until the R foot contacted the ground (the L knee remained on the ground). The same process was then repeated on the L limb. | R peak amplitude, MED (IQR1–3) LBP: 1.25 (1.00–2.16) nLBP: 1.60 (1.00–2.10), p = .007 L peak amplitude, MED (IQR1–3) LBP: 1.19 (1.04–2.31) nLBP: 1.81 (1.02–2.11), p < .001 R iEMG, MED (IQR1–3) LBP: 0.66 (0.17–1.00) nLBP 1.00 (0.35–1.48), p = .004 L iEMG, MED (IQR1–3) LBP: 1.00 (0.57–1.00) nLBP 1.00 (0.87–2.00), p = .001 Normalisation: % of average activity during the kneeling task. | Not measured | Not measured | R, % of duration of task, MED (IQR1–3) LBP: 0.68 (0.11–0.94) nLBP: 0.44 (0.07–0.74), p = .001 L, % of duration of task, MED (IQR1–3) LBP: 0.86 (0.13–1.00) nLBP: 0.21 (0.05–0.83), p < .001 | Participants with LBP demonstrated statistically significant lower amounts of glutues medius muscle activity, and later times of peak activation compared to those without LBP. |
Ringheim et al. 2015 [31] | EMG TeleMyo 2400 (Noraxon) | Participants stood barefoot for 15 min. | Start RMS (%Max) LBP: 10.4 (6.3–36.5) nLBP 8.3 (4.9–11.6), p = .19 Slope RMS (%Max) LBP: − 1.5 (− 9.1–7.7) nLBP: − 0.6 (− 1.7–3.5), p = .66 Normalisation: % of maximum voluntary contraction during standing hip flexion and extension in an isokinetic device. | Coefficient of variation LBP: 27.4 (23.4–48.5) nLBP: 31 (17.5–39.7), p = .62 Slope MDF (Hz/min) LBP: 12.9 (− 9.0–21.3) nLBP: 2.5 (− 8.0–21.3), p = .28 | Not measured | Not measured | No statistically significant differences in the amount of gluteus medius muscle activity or variability of muscle activity over time between those with and without LBP. |
Embaby et al. 2013 [24] | Myomonitor® Wireless EMG System | Participant stood shod for 30 min. | Not measured | R first 5 min, MDF LBP: 172.40 (±48.96) nLBP: 171.41 (±38.87), p > .05 R Last 5 min, MDF LBP: 158.91 (±49.03) nLBP: 195.19 (±34.74), p < .05 L First 5 min, MDF LBP: 159.29 (±48.81) nLBP: 173.12 (±41.36), p > .05 L Last 5 min, MDF LBP: 177.18 (±53.95) nLBP: 185.04 (±48.04), p > .05 | Not measured | Not measured | Participants with LBP demonstrated statistically significant less gluteus medius muscle activity on the R during the last 5 min compared to those without LBP (indicating greater fatigue). Differences in the first 5 min on both sides, and the last 5 min on the L side, were not statistically significant. |
Hungerfor-d et al. 2003 [26] | Noraxon Telemyo 8 EMG | Participants stood on one leg then flexed the contralateral hip and knee to 90 degrees. Five trials per side were conducted. | Peak amplitude Specific values for gluteus medius not reported, p > .05 Normalisation: % of maximal activity during the single leg standing task. | Not measured | Specific values (in ms) for gluteus medius not reported, p > .05 | Not measured | No statistically significant differences in the amount of activity or time of onset of the gluteus medius muscle in those with and without LBP. |
Sutherin et al. 2015b [34] | EMG100C Biopac | Participants performed 5 consecutive isometric hip abduction contractions, in a side-lying position at zero degrees of hip abduction, each lasting 30 s. This was done on both sides, separated by 15 min of rest. | RMS No specific values reported, p > .05 Normalisation: % of MVIC during side-lying hip abduction with manual resistance. | MDF No specific values reported, p > .05 | Not measured | Not measured | No statistically significant differences in the amount or duration of gluteus medius muscle activity between those with and without LBP. |
Nelson-Wong et al. 2013 [6] | Biopac MP150 | Participants performed the active hip abduction (AHAbd) test in a side-lying position. Note: A positive value indicates the first listed muscle activates first and a negative value indicates the second listed muscle activates first. | Not measured | Not measured | REO-RGMd LBP: − 0.18 s (±0.28) nLBP: 0.10s (±0.31), p = .015 LEO-RGMd LBP: − 0.03 s (±0.37) nLBP: 0.03 s (±0.37), p = .65 RIO-RGMd LBP: − 0.11 s (±0.33) nLBP: 0.14 s (±0.33), p = .033 LIO-RGMd LBP: 0.02 s (±0.37) nLBP: 0.08 s (±0.40), p = .62 RES-RGMd LBP: 0.05 s (±0.34) nLBP: 0.06 s (±0.33), p = .94 LES-RGMd LBP: − 0.11 s (±0.29) nLBP: 0.07 s (±0.36), p = .15 REO-LGMd LBP: 0.17 s (±0.38) nLBP: 0.05 s (±0.30), p = .35 LEO-LGMd LBP: 0.04 s (±0.39) nLBP: 0.12 s (±0.35), p = .55 RIO-LGMd LBP 0.01 s (±0.42) nLBP: 0.19 s (±0.28), p = .15 LIO-LGMd LBP: − 0.04 s (±0.32) nLBP: 0.17 s (±0.35), p = .049 RES-LGMd LBP: − 0.24 s (±0.33) nLBP: 0.09 s (±0.39), p = .014 LES-LGMd LBP: 0.01 s (±0.34) nLBP 0.10 s (±0.38), p = .44 | Not measured | During the R AHAbd test, participants with LBP demonstrated statistically significant earlier activation of the R gluteus medius muscle relative to the ipsilateral trunk flexors (RIO and REO), compared to controls. During the L AHAbd test, participants with LBP statistically significantly activated the LGMd prior to the contralateral trunk extensors (RES) and ipsilateral IO, compared to controls. |
Rabel et al. 2013 [30] | Noraxon Telemyo 2400 T EMG | Participants performed the active hip abduction (AHAbd) test in a side-lying position. Note: the larger the number, the longer it took for that muscle to activate. | Not measured | Not measured | LBP: 1629 ms (±1715) nLBP: 648 ms (±150), p = .115 | Not measured | No statistically significant differences in time to onset for the gluteus medius muscle in those with and without LBP. |
Hides et al. 2016 [25] | Power Trak II handheld dynamometer | Participants were positioned supine with hip in neutral. A strap was used to stabilise pelvis. Participants abducted their hip against the dynamometer at a maximal effort for 5 s with examiner resistance applied. Three trials with a 15 s rest between each trial. | Strength | Those with LBP had statistically significantly less gluteus medius muscle strength on the stance limb, but significantly more on the kicking limb. | |||
Stance leg LBP: 154.1 Nm (±10.0) nLBP: 161.5 Nm (±6.6), p < .05 Kicking Leg LBP: 165.1 Nm (±11.8) nLBP: 143.9 Nm(±7.8) p < .05 | |||||||
Kendall et al. 2010 [5] | Lafayette manual muscle tester | The test limb was positioned parallel to the treatment table, directly in line with the hip. 3 maximal voluntary isometric strength contractions with a 30s rest period between trials was performed | LBP: 6.6 (N/kg) (5.4 to 7.7) nLBP: 9.5 (N/kg) (7.2 to 11.9) p = .03 | LBP participants had statistically significantly less gluteus medius muscle strength compared to those without LBP. | |||
Arab et al. 2010 [4] | Pressure meter | Side lying hip abduction test. Three maximal voluntary isometric contractions, held for 5 s with 15 s rest between trials. | LBP: 27.87 kPa (± 7.95) nLBP: 33.51 kPa (± 7.29), p < .001 | LBP participants had statistically significantly less gluteus medius muscle strength compared with subjects without LBP. | |||
Cai et al. 2015 [23] | Isokinetic dynamometer | Three standing concentric muscle contractions (torque) measured with leg secured to dynamometer | Male LBP: 1.49 (Nm/kg) (±0.39) Male nLBP: 1.52 (Nm/kg) (±0.41) Female LBP 1.05 (Nm/kg) (±0.39) Female nLBP: 1.17 (Nm/kg) (±0.35) p = .596 (Gp) p = .743 (Gp by Sex) | No statistically significant differences in gluteus medius strength between those with and without LBP. | |||
Penney et al. 2014 [29] | Lafayette Manual Muscle Tester | Participants were laid on their side and abducted their hip whilst the examiner resisted with their hand just superior to the ankle. Two maximal resisted voluntary contractions for a 3s max voluntary contraction with 1 min rest in-between. | Right LBP: 1.04 (N/Kg) (± 0.32) Right NLBP: 1.36 (N/Kg) (±0.33) Left LBP: 1.05 (N/Kg) (± 0.26) Left nLBP: 1.23 (N/Kg) (±0.30) p = .04 (right) p = .002 (left) | LBP participants had statistically significantly less gluteus medius muscle strength on both sides compared to those without LBP. | |||
Nourbakh-sh et al. 2002 [3] | Pressure meter | Side lying hip abduction test. Three maximal voluntary isometric contractions, held for 5 s | LBP: 26 kPa (±8) nLBP: 32 kPa (±7), p < .01 | LBP participants had statistically significantly less gluteus medius muscle strength compared to those without LBP. | |||
Sutherlin et al. 2015a [33] | Isokinetic dynamometer | Side lying hip abduction, three maximal voluntary isometric contraction (torque). Hip-abduction trials lasting 5 s were recorded, with 30 s of rest between trials. | LBP: 1.64 (Nm/Kg) (±0.44) nLBP: 1.65 (Nm/Kg) (± 0.28), p = .944 | No statistically significant differences in gluteus medius strength between those with and without LBP. | |||
Cooper et al. 2016 [16] | Subjective Measure | Gluteus medius strength was tested by placing subject in side-lying and having the subject abduct and slightly extend the hip while keeping the pelvis rotated slightly forward. Resistance was applied at the ankle. Graded 1–5. | LBP: 3.35 (±0.73) nLBP: 4.46 (±0.50), p < .001 | LBP participants had statistically significantly less gluteus medius muscle strength compared to those without LBP. | |||
Cooper et al. 2016 [16] | Subjective observation | While standing one hip is flexed. Trendelenburg sign considered present if the subject was unable to maintain the pelvis level or had to shift the trunk to keep the pelvis level. | Presence of Trendelenburg sign occurred 54.2% of the time in those with LBP compared to 9.7% of the time for those in the no LBP group p < .001 | LBP participants were statistically significantly more likely to demonstrate a trendelenburg sign, indicating gluteus medius muscle weakness. | |||
Kendall et al. 2010 [5] | Treadmill and Vicon | Subjects performed a baseline standing trial, 2 static Trendelenburg trials, and a 30s walking trial on a treadmill at a speed of 1.34 m/s. | LBP right: − 1.9 deg (− 7.0 to 1.7) nLBP right: − 2 deg (− 4.8 to 1.2) LBP left: − 1.6 deg (− 1.6 to 2.6) nLBP left: − 2.2 deg (− 4.3 to 0.7) Negative values indicate hip hike; positive values indicate pelvic drop. No significant differences. | No statistically significant differences in presence of Trendelenburg sign between those with and without LBP, indicating no difference in dynamic strength provided by the gluteus medius. | |||
Farasyn et al. 2005 [35] | Fischer pressure algometer | Lying prone the rate of pressure increase was maintained at a constant rate of on average 1Kg/sec. Three short consecutive PPT measurements with 10 s in between were performed. | Trigger points | Participants with LBP had a statistically significant lower threshold for pain than those without LBP. | |||
LBP: 6.1 kg/cm2 (±1.6) nLBP: 7.2 kg/cm2 (± 1.5), p < .001 | |||||||
Cooper et al. 2016 [16] | Palpation | Gluteus medius was palpated from its insertion, muscle belly and origin. Tenderness was defined as pain reported by patient and when using enough pressure to blanch the examiner’s nail. | LBP (affected side): Tenderness associated with triggers points was more prevalent (68.10%) on the side of the body affected by LBP nLBP: Tenderness associated with triggers points occurred in 11.20% of the gluteus medius muscles of those without LBP p < .001 LBP (affected side): Tenderness associated with triggers points was more prevalent (68.10%) on the side of the body affected by LBP LBP (unaffected side): Tenderness associated with trigger points was less prevalent (4.80%) on the side of the body that was not affected by LBP. p < .001 | Participants with LBP had a statistically significant greater number of trigger points in the gluteus medius muscle compared to those without LBP, as well as, more on the affect side compared to the unaffected side (for unilateral LBP suffers). | |||
Iglesias-Gonzalez et al. 2013 [27] | Palpation | The gluteus medius was palpated by an experience clinician. No other details reported. | Latent TrP LBP (painful side), n (% of LBP participants): n = 5 (12%) nLBP, n (% of nLBP participants): n = 2 (5%), p < .001 Latent TrP LBP (less painful side), n (% of LBP participants): n = 7 (17%) nLBP, n (% of nLBP participants): n = 2 (5%) p < .001 Active TrP LBP (more painful side), n (% of LBP participants): n = 15 (35%) LBP (less painful side), n (% of LBP participants): n = 16 (38%) p > .05 | Participant with LBP had a statistically significant greater number of latent trigger points in both the painful and less painful sides compared to those without LBP. The number of active trigger points on either side in those with LBP was not statistically significant. | |||
Njoo et al. 1994 [36] | Palpation | Lying prone the gluteus medius was palpated and number of trigger graded as present or absent. | LBP, n (% of LBP participants): n = 21 (34%) nLBP, n (% of nLBP participants): n = 4 (6%), p < .05 | Participants with LBP had a statistically significant greater number of trigger points in the gluteus medius muscle compared to those without LBP. | |||
Aboufazeli et al. 2018 [39] | Ultrasound (GE, Model GE LOGIQ S6, MA, USA), 5.0 MHz curvilinear transducer | Side-lying at rest and during resisted hip abduction (0.5Kg weightused for resistance). Only painful side measured in LBP group. In the control group, the thicknesses of both sides were measured and then averaged. Thickness was measured as the distance between the superior and inferior hyperechoic muscle fascias, at the middle of each image. | Cross-sectional area and muscle thickness | Participants with LBP demonstrated a statistically significant smaller change in gluteus medius muscle thickness, from rest to during resisted hip abduction, compared to those without LBP. | |||
Resting thickness LBP: 16.75 mm (0.33) nLBP: 22.00 mm (0.11) Contracted thickness LBP: 26.15 mm (0.90) nLBP: 33.90 mm (0.10) Thickness change LBP: 9.40 mm nLBP: 11.90 mm, p = .025* *Only reported for change between groups | |||||||
Mendis et al. 2016 [37] | 1.5 T Siemens Magnetom SonataMR | Lying supine on the imaging table with knees and hips supported in neutral position. | LBP: 35.8 cm2 (±1.5) nLBP: 37.3 cm2 (±0.9), Specific statistical values not reported | No statistically significant differences between the thickness of the gluteus medius muscle between those with and without LBP. | |||
Skorupska et al. 2016 [32] | 1.5 Tesla Signa HDe system (GE) | Lying supine | No specific values for the gluteus medius muscle were reported (mm3). | No statistically significant differences between each side. Note: No comparisons made between groups. |