Table 1 Characteristics of included studies

Vaegter et al. [53]

Chronic low back pain

N = 146

F92 M54

Age = 52.2 (13.2) years

Cognitive functional therapy:

8 supervised Rxs over 12 wks including (1) making sense of pain; (2) exposure with control; (3) lifestyle change.

Encouraged to perform 20–30 min of physical activity daily based on personal preference.

Multidisciplinary intervention combining (1) medical Rx with a specialist pain consultant & (2) one or more of the following: individual consultations with a pain psychologist, or social worker with CBT

Training, or participation in a group session with relaxation therapy or mindfulness.

PPT (local &remote)

-kPa

PPT assessed at the right erector spinae muscle (local) & left upper trapezius muscle (remote) using a handheld pressure algometer (Somedic Sales AB, Norra Melby, Sweden) with a stimulation area of 1 cm², pressure rate of 30 kPa/s.

Pre Intervention

Post intervention

6-mth f/up

PPT (local) Mean (IQR)

Pre: G1: 183.3 (132.4–278.0)

Post: G1: 230 (193.5–363.5)

6 mth f/up: G1: 257.5 (192.0-367.0)

PPT (remote)

Pre: G1: 189.5 (121.0-251.0)

Post: G1: 208.75 (152.0-296.5)

6 mth f/up: G1: 218.0 (160.5–308.0)

Sig. increase in lumbar PPTs at end of Rx. period & at 6-th f/up in CFT group. No sig. increase in remote PPTs at both time points. Moderate association between PPT lumbar & pain intensity at both time points.

Bodes-Pardo et al. [41]

Chronic low back pain

N = 56

F 44 M 12

Age = 47.1 (10.1) years

2 group session (30–50 min) of Pain Neuroscience Education & information leaflet. Daily exercise for 3-months: multimodal exercise program consisting of motor control exercises, stretching & aerobic exercise.

Daily exercise only (as experimental group)

PPT (local & remote)

-kg/cm²

PPT assessed 5 cm lateral to the spinous process of L3 (local) & at 2 cm from the lateral epicondyle (remote) using an analogue Fisher algometer (Force Dial model FDK 40) with a surface area of 1cm².

CSI

Pre intervention

Post intervention

1 mth f/up

PPT (local) Mean (95% CI)

Pre: G1: 2.8(2.5-3.0)

Post: G1: 3.9(3.6–4.3)

1 mth f/up: G1: 4.6(4.3–4.9)

Pre: G2: 3.0(2.7–3.2)

Post: G2: 3.2(3.0-3.5)

1 mth f/up: G2: 3.6(3.3–3.9)

PPT (remote)

Pre: G1: 3.6(3.2-4.0)

Post: G1: 3.6(3.2-4.0)

1 mth f/up: G1: 3.7(3.3–4.1)

Pre: G2: 3.8(3.5–4.2)

Post: G2: 4.0(3.6–4.3)

1 mth f-up: G2: 3.9(3.6–4.3)

Sig. differences between groups for local PPT in favour of experimental group at 1 mth f/up No significant between group differences for remote PPTs at 1 mth f/up Follow up CSI scores not reported.

Sitges et al. [52]

Chronic low back pain

N = 59

F 42 M 17

Age = 46.8 (8.4) years

Self-managed (G2) or supervised (G1): twice a wk for 4 wks: (1) pain education video < 4 min (2) 50 min exercise, strength exercises, motor control, relaxation routine, flexibility and self-massage.

nil

PPT (local & remote)

-kg/cm²

PPT assessed unilateral erector spinae muscle, 2 cm from spine at most painful point (local) & at the forefinger (remote) using a digital algometer (FPIX 50; Wagner Instruments).

Pre intervention

Post intervention

PPT (local) Mean (SD)

Pre: G1: 3.49(1.17)

Post: G1 3.23(1.20)

Pre: G2 3.66(1.23)

Post: G2: 3.39(1.18)

PPT (remote)

Pre: G1: 3.91(1.01)

Post: G1: 3.69(1.19)

Pre: G2: 4.13(1.02)

Post: G2: 4.07(0.96)

No sig. differences between the groups were found in local or remote PPTs post intervention.

Malfliet et al. [46]

Chronic low back pain

N = 120

F 73 M 47

Age = 39.8 (12.4) years

Biopsychosocial Approach: Pain Neuroscience Education, Cognition-Targeted. Time‐Contingent Exercise Program, (“Perform this exercise 10 times regardless the symptoms it might induce.”)

Both interventions comprised 3 educational sessions (group session, home-based online module, and individual session) & 15 one-on-one exercise sessions over 12 wks

Biomedical Approach: Traditional Back/Neck School Pain-Contingent Exercise Program (“Stop or adapt the exercise as soon as symptoms occur.”)

PPT (local, distal, remote)

-kgF

PPT assessed at the symptomatic sites (trapezius muscle midway between C7 & the acromion tip & 5 cm lateral of the spinous process of L3 (local) & remote sites at quadriceps muscle (distal) & the web between the thumb and index finger (remote) using a digital pressure algometer with a 1-cm² tip (Wagner Instruments)

CPM measured using a cold-water bath (12 °C; Versacool) for 2 minutes’ immersion of the hand contralateral to the PPT measurements.

CSI

Pre intervention

Post intervention

PPT (local) Mean (SD)

Pre: G1: 4.56(2.40)

Post: G1 6.15(2.73)

Pre: G2 4.43(2.45)

Post: G2: 5.18(2.81)

PPT (remote)

Pre: G1: 3.6(1.88)

Post: G1: 4.41(2.01)

Pre: G2: 3.6(1.88)

Post: G2: 4.05(2.09)

PPT (distal)

Pre: G1: 5.33(2.57)

Post: G1: 6.54(0.37)

Pre: G2: 5.08(2.53)

Post: G2: 5.65 (0.38)

Local PPTs in experimental group showed a clinically relevant (> 15%) increase in PPTs post intervention. Nil noted in remote or distal PPTs.

CPM Mean (SE)

Pre: G1: 1.08(0.20)

Post: G1: 1.51(0.21)

Pre: G2: 1.05(0.19)

Post: G2: 1.19(0.22)

No sig. CPM group difference post intervention.

CSI Mean (SE)

Pre: G1: 40.02(1.47)

Post: G1: 30.67(1.69)

6 mth f/up: G1: 25.24(1.73)

12 mth f/up: G1: 29.36(1.67)

Pre: G2: 39.88(1.47)

Post: G2: 35.24(1.71)

6 mth f/up: G2: 34.22(1.77)

12 mth f/up:G2: 35.14(1.70)

Experimental group showed sig. lower CSI scores (medium effect sizes) than control group post intervention.

Cabak et al. [42]

Chronic back pain

N = 68

F 49 M 19

Age = 58.8 (10.5) years

1 consultation per mth for 3 mths.

(1) history taken (2) health education, individualised psychological support (3) instructions on home exercise- A set of ‘5 exercises in 5 minutes’ (4) 15 minute massage.

Waiting list

PPT (local)

-kg/cm²

PPT assessed at selected pain trigger points on the trapezius muscle, levator scapula muscle and multifidus muscle, on both sides of the spine (local) & at quadriceps muscle & the web between the thumb & index finger (remote) using a Pain Test Algometer FPX.

Pre intervention

Post intervention

PPT scores Mean (SD)

Post-intervention scores only

G1: Traps(L) 4.636(0.980)

G1: Traps(R) 4.786(1.111)

G1: Lev Scap (L) 5.533(1.209)

G1: Lev Scap (R) 5.828(1.065)

G1: Multifidus (L) 5.995(0.926)

G1: Multifidus (R) 6.238 (0.839)

G2: Traps(L) 3.363(1.281)

G2: Traps(R) 3.398(1.184)

G2: Lev Scap (L) 3.761(1.215)

G2: Lev Scap (R) 3.894(1.137)

G2: Multifidus (L) 3.813(1.263)

G2: Multifidus (R) 3.798(1.293)

PPT in all local muscles under analysis were sig. higher in the experimental group compared to the control group post-intervention.

Ris et al. [49]

Chronic neck pain

N = 200

F 149 M 51

Age: 45.2 years

4 sessions (1.5 h each, once per month) focusing on understanding & acceptance of pain, goal setting, participation in social and work-related contexts based on a cognitive concept.

8 sessions of 30 min instruction in progressive individually tailored exercises (1) neck flexor and extensor function, (2) standing balance, oculomotor training & neuromuscular function of the shoulder girdle.

Pain Education (as experimental group) alone

PPT (local & remote)

-kgF

PPT assessed at infraspinatus and C5/6 level (local) & at anterior tibialis (remote) using an algometer (Wagner, FPX algometer, USA)

Pre intervention

Post intervention

Difference of PPT change scores between groups at f-up.

PPT local Mean (95% CI)

Infraspinatus(L): 1.97(-2.40-6.31)

Infraspinatus(R): 0.07(-0.35-0.50)

Cervical (L): -0.21(-0.55-0.15)

Cervical (R):-0.76(-1.76-0.24)

PPT remote

Tib Ant (L): -0.54(-0.94-0.15)

Tib Ant (R): -0.35(-0.75-0.04)

Local and remote PPT improved sig. for the experimental group compared to control.

Galan-Martin et al. [44]

Chronic spinal pain

N = 170

F 136 M 34

Age = 51.1 (11.4) years

Pain Neuroscience Education-6 sessions (10 h) & 18 sessions of group therapeutic exercise over 6 wks

Usual physiotherapy Rx, 15 sessions (15 h) of thermotherapy & analgesic electrotherapy in the area or areas of pain, & exercises recommended by the Spanish Society of Physical Medicine & Rehabilitation

PPT (local)

-kg/cm²

PPT assessed at 4 reference points(P1,2,3,4); midpoint between the acromion & the spinal process of the seventh cervical vertebral, bilaterally, & the midpoint between the highest part of the superior border of the iliac crest & the spinal process at the same height, also bilaterally (local) using an algometer with an application area of 1 cm² (Warner Instruments FPX-100).

Pre intervention

Post intervention

6 mth follow-up

PPT intragroup difference (6mth-Pre)

Local PPTs Mean (95% CI)

P1 G1: 1.8 (1.5 -2.2)

P1 G2: 0 (-0.2-0.3)

P2 G1:1.9 (1.6 -2.2)

P2 G2: 0.2 (-0.1- 0.5)

P3 G1: 2.4 (2- 2.8)

P3 G2: 0.2(-0.1- 0.5)

P4 G1: 2.5 (2- 2.9)

P4 G2: 0.2 (-0.1-0.5)

Sig. intragroup differences for all local PPTs between six months assessment and initial assessment and significant intergroup differences between six months assessment and initial assessment in favour of experimental group

CSI scores Mean (SD)

Pre: G1: 43.4(12.5)

Post: G1: 25.7(10.8)

6 mth f/up: G1: 25.8(10.5)

Pre: G2: 38.6(11.7)

Post: G2: 37.7(12.4)

6 mth f/up: G2 37.4(13.5)

At 6 mth f/up there was significant differences between groups favouring G1 for CSI scores.

Skou et al. [50]

Knee Osteoarthritis

N = 100

F 51 M 49

Age: 65.9 (8.9) years

3-mth programme Education, 2 × 60-min -focus on disease characteristics, OA pain & how to control & monitor it during exercise, Rx & help to self-help by actively engaging the patients +& Neuromuscular Exercise training 60 min twice weekly. Optional pain medication, insoles, dietary advice

Usual care-2 leaflets with education about OA

PPT (local, remote, distal)

-kPa

PPT assessed at four sites at the knee, all in proximity to the patella (local) & at tibialis anterior muscle (distal) & extensor carpi radialis longus muscle (remote) using a handheld algometer with a 1 cm² probe (Algometer Type II, Somedic AB, Hoerby, Sweden)

Pre intervention

Post intervention

PPT local Mean (SD)

Pre: G1: 521.71(241.42)

Post: G1 595.79(251.23)

Pre: G2: 572.80(297.16)

Post: G2: 628.37(287.15)

PPT remote

Pre: G1: 402.99(180.86)

Post: G1 415.99(198.03)

Pre: G2: 401.48(234.22)

Post: G2: 198.03(166.59)

PPT distal

Pre: G1: 575.74(295.15)

Post: G1: 664.70(332.39)

Pre: G2: 610.40(346.21)

Post: G2: 670.69(293.95)

No statistical difference in change in PPTs (from baseline to 3 months) was found between groups.

Polaski et al. [48]

Chronic low back pain

N = 52

F 25 M 27

Age = 37.6 (15.4) years

5 days per wk for 4 wks -Guided meditation recording followed by 30 min of treadmill walking.

Audio-book for 12–17 min followed by a 30-minute rest period 5 times per week for 4 wks

PPT (local & remote)

-kg/cm²

PPT assessed at participant’s low back (local) and forearms (remote) at specific testing sites using handheld algometer with a 1 cm2 probe (Wagner Instruments, Greenwich, CT, USA).

Additional measures: MS, MP, CHI, CHU, CPI, CPU

Pre intervention

Post intervention

PPT local Mean (SD)

Pre: G1: 5.58(1.8)

Post: G1: 5.70(1.6)

Pre: G2: 4.71(2.0)

Post: G2: 4.78(1.8)

PPT remote

Pre: G1: 3.63(0.9)

Post: G1: 3.93(1.0)

Pre: G2: 3.54(1.4)

Post: G2: 3.53(1.3)

No sig. Rx. effects for constant heat pain intensity, constant heat pain un-pleasantness, pressure pain threshold, constant pressure pain intensity, or constant pressure pain unpleasantness

Holm et al. [45]

Knee Osteoarthritis

N = 90

F 52 M 38

Age = 64.8 (10.0) years

2 education sessions (1) osteoarthritis disease characteristic, symptoms, risk factors, Rx options. (2) exercise as Rx, coping strategies & self-management

Neuromuscular Exercise: twice weekly (60 min sessions) for 12 wks (warm up, circuit exercises, cool down)

Strength training: one set of low-intensity, high-repetition (30-60RM) knee extensions followed by four sets of high-intensity (8-12RM) leg-press in gym machines

Neuromuscular exercise(as experimental group) & education (as experimental group)

PPT (local & remote),

-kPa

PPT; assessed at painful/most painful knee (local) & contralateral knee (remote) using a computer-controlled cuff algometer (Cortex Technology, Hadsund & Aalborg University) including two 13-cm wide cuffs (VBM). TS was assessed by inflating the cuff on the index leg. The participant was then subjected to ten short-lasting pressure stimuli (1-s each), using the previously recorded pain tolerance threshold cuff pressure, with 1-s breaks between each stimulus.

CPM; assessed by inflating the cuff on contralateral leg to 70% of recorded PTT as the conditioning stimulus. The cuff on the index leg was inflated continuously with a rate of 1 kPa/s. The participants were instructed to press the pressure release button when the pain was intolerable.

TS; assessed by inflating the cuff on the index leg. The participant was subjected to ten short-lasting pressure stimuli (1-s each), using the previously recorded PTT cuff pressure, with 1-s breaks between each stimuli

Pre intervention

6-wks

Post intervention

PPT local Marginal means (95% CI)

Pre: G1: 22.1(7.9)

6 wks: G1: 23.7(21.4 - 26.0)

Post: G1: 24.6(22.1 - 27.1)

Pre: G2: 20.4(9.7)

6 wks: G2: 19.7(17.6 - 21.8)

Post: G2: 19.6(17.4 - 21.7)

PPT remote

Pre: G1: 22.9(11.5)

6 wks: G1: 24.7(22.6 - 26.9)

Post: G1: 23.4(21.1 - 25.6)

Pre: G2: 19.3(8.5)

6 wks: G2: 19.1(17.2 - 21.1)

Post: G2: 20.9(18.9 - 22.9)

CPM

Pre: G1: 1.2(10.3)

6 wks: G1: 2.8(0.1 - 5.4)

Post: G1: 3.7(0.9 - 6.5)

Pre: G2: 2.3(9.3)

6 wks: G2: 3.8(1.4 - 6.2)

Post: G2: 3.3(0.9 - 5.7)

TS

Pre: G1:1.9(1.4)

6 wks: G1: 1.7(1.3 - 2.2)

Post: G1: 1.5(1.1 - 2.0)

Pre: G2: 2.3(1.5)

6 wks: G2: 2.1(1.7 - 2.5)

Post: G2: 1.5(1.2 - 1.9)

Statistically sig. difference between groups, at wk 6 & 12, with higher threshold in experimental group for PPT local. Sig. difference in experimental group at 6 wks but not at 12 wks in PPT remote. No sig. differences between groups in TS or CPM at 6 or 12 wks.

Georgopolulos et al. [51]

Chronic low back pain

N = 97

F 69 M 28

Age = 57(13) years

CBT based PT

MDT- included workshop sessions delivered by a multidisciplinary team- address chronic pain mechanisms, anatomy, goal-setting techniques, graded exercise & pacing, stress management, challenging negative thoughts, relaxation, imagery & mindfulness as well as communication skills & medication use.

PPT, CPM, TS

kPA

PPT; assessed using a handheld digital algometer (Medoc-AlgoMed Advanced Medical Systems- Computerised Pressure Algometer, Israel. The brachioradialis muscle, approximately 5 cm distal to the lateral epicondyle, was chosen for all modalities as a site distant from the primary area of pain in individuals with CLBP.

TS; assessed twice by repeated application to the forearm of a punctate stimulus (256 mN) using the retractable blunt needle of a specially manufactured pen (MRC Systems

GmbH; The Pin Prick, Germany A single punctate stimulus was applied on their dominant forearm, followed by 10 repetitive stimuli at a rate of 1/s.

CPM; assessed using contralateral forearm ischaemic pain as the conditioning stimulus, rated as 4 on an 11-point current pain NRS.

Baseline scores only

PPT Mean (IQR)

205.8(148.2-297.6)

TS

1.0 (0.4–2.8)

CPM

59.1(5.6–99.3)

Chimenti et al. [43]

Chronic Achilles tendinopathy

N = 66

F 37 M 29

Age = 43.4 (15.1) years

3 phase exercise programme: isometric ex, heel raises, spring exercise & Pain Science Education

Wk 1–7: 6/7 one-to-one physiotherapy visit. Wk 9-12-instructed to maintain HEP, 10 wks-phone call

Exercise programme (as experimental group) & Pathoanatomical education

PPT (local &remote)

kPa

PPT; assessed at the Achilles tendon & semitendinosus tendon on painful side (local) & contralateral side (remote) using a pressure algometer (Somedic Algometer TypeII, Horby Sweden, probe 1 cm²)

CPM; the conditioning stimulus involved participants placing their hand in a cold (6+/-0.5 ̊C) water bath for 120 s & rating the pain in their hand at 5 s & 20 s. The neutral stimulus involved participants placing their hand in a room temperature (22+/-1.0 ̊C) water bath for 120 s. A formula was used to calculate CPM.

TS technique not described in text.

Pre intervention

Post intervention

PPT local Mean(SD)

Pre: G1: 476.6 (212.5)

Post: G1: 477.0(142.1)

Pre: G2: 415.1(171.4)

Post: 465.1(242.8)

PPT remote

Pre: G1: 529.9(202.9)

Post: G1: 535.0(214.3)

Pre: G2:560.8(262.0)

Post: G2: 525.3(242.1)

CPM

Pre: G1: 27.4(33.6)

Post: G1: 14.2(26.1)

Pre: G2: 24.4(26.3)

Post: G2: 16.9(27.3)

TS

Pre: G1: 2.1(1.3)

Post: G1: 1.9 (1.6)

Pre: G2: 2.1(1.4)

Post: G2: 2.0(1.2)

No sig. changes in PPT local, remote, TS or CPM post intervention

Matias et al. [47]

Chronic idiopathic neck pain

N = 52

F 43 M 9

Age = 21 (2.0) years

Pain neuroscience education (the neurophysiology of pain, the transition from acute to chronic pain & the nervous system’s ability to modulate the pain experience)

& Exercise- aimed at increasing the endurance & strength of the deep neck flexors &extensors 30 min sessions, 1 per wk, 4 wks.

Exercise (as experimental group)

PPT (local)

PPT assessed at right & left upper trapezius & the articular pillar of C5/C6 (local), using a pressure algometer (JTECH Medical Industries, Salt Lake City, US)

Pre intervention

Post intervention

PPT local Mean (SD)

Pre: G1: C1-C2(R) 15.0(5.6)

Post: G1: C1-C2(R) 15.4(5.3)

Pre: G2: C1-C2(R) 15.0(4.3)

Post: G2: C1-C2(R) 16.3(6.0)

Pre: G1: C1-C2(L) 14.6(5.7)

Post: G1: C1-C2(L) 15.3(5.6)

Pre: G2: C1-C2(L) 15.6(4.4)

Post: G2: C1-C2(L) 15.9(5.7)

Pre: G1: C5-C6® 14.9(5.6)

Post: G1: C5-C6® 15.7(6.2)

Pre: G2: C5-C6(R) 15.8(4.9)

Post: G2: C5-C6(R) 16.1(4.4)

Pre: G1: C5-C6(L) 15.3(5.5)

Post: G1: C5-C6(L) 15.5(5.6)

Pre: G2: C5-C6(L) 16.8(5.6)

Post: G2: C5-C6(L) 16.9(5.7)

Pre: G1: Mid traps(R) 17.4(5.5)

Post: G1: Mid traps(R) 17.5(5.7)

Pre: G2: Mid traps(R) 18.4(4.9)

Post: G2: Mid traps(R) 17.3(4.7)

Pre: G1: Mid traps(L) 17.5(6.0)

Post: G1: Mid traps(L) 17.3(5.2)

Pre: G2: Mid traps(L) 19.5(5.2)

Post:G2: Mid traps(L) 17.4(4.6)

Neither intervention nor time was found to have a sig. effect on pressure pain threshold measurements (P > 0.05).