Significant Differences In Pressure Pain Threshold Research Articles

Instrument Assisted Soft Tissue Mobilization versus Integrated Neuromuscular Inhibition Technique in Nonspecific Chronic Neck Pain: Single-blinding Randomized Trial

ObjectiveThis study aimed to compare the effects of instrument-assisted soft tissue mobilization (IASTM) vs integrated neuromuscular inhibition technique (INIT) on pain intensity, pressure pain threshold, neck disability, and electrophysiological properties in nonspecific chronic neck pain. MethodsWe performed a pre-post prospective randomized controlled trial on 90 participants with nonspecific chronic neck pain. The participants were chosen randomly from physical therapy out-patient clinics in the Giza governorate and allocated randomly by permuted block to the following 3 groups: Group A received INIT on the upper trapezius in addition to supervised traditional therapy (STT) as hot pack, stretching and strengthening exercises, Group B received IASTM on the upper trapezius in addition to STT, and Group C received STT only. Treatment was 3 times per week for 4 weeks. Pain intensity by visual analog scale (VAS), pressure pain threshold (PPT) by commander algometer, neck disability by Arabic Neck Disability Index (ANDI), and electrophysiological properties in the form of muscle amplitude by root mean square (RMS), and fatigue by median frequency (MDF) were measured at baseline and after 4 weeks. ResultsIn the within-group analysis, there was a statistically significant decrease in VAS, ANDI, and RMS% values within each group with favor to INIT. In PPT and MDF, there was a significant increase within each group with regard to INIT as P value <.05. In the between-group analysis at posttreatment, the results reported a statistically significant difference between INIT and STT, and also between IASTM and STT in all variables. Between INIT and IASTM, there was no statistically significant difference in VAS and NDI, but there was a statistically significant difference in PPT, RMS%, and MDF. The post hoc test reported improvement in all variables in all groups, with more favor to the INIT group in PPT and electrophysiological properties only. ConclusionIn this study, we found no statistically significant differences between INIT and IASTM in VAS and ANDI posttreatment, but there were differences between INIT and STT group and IASTM and STT group.

Patients with neuropathic pain from lumbosacral radiculopathy demonstrate similar pressure pain thresholds and conditioned pain modulation to those with fibromyalgia

ObjectiveThe purpose of the study was to evaluate pain thresholds, impairment of the endogenous pain modulatory system, and self-reported cognitive-emotional and central sensitization-related symptoms among three subject groups: a rarely studied patient cohort with neuropathic pain from lumbosacral radiculopathy (NPLSR), patients with fibromyalgia (FM) and healthy controls (HC). MethodsPatient-reported pain-related symptomology was evaluated with psychometricallyvalidated questionnaires. Pressure pain threshold (PPT), heat pain threshold (HPT), and cold pain threshold (CPT) were assessed in the low back and contralateral forearm. Conditioned pain modulation (CPM) was evaluated with a recently introduced methodology that accounts for a standard error of measurement. ResultsCompared to the HC subjects, the FM and NPLSR subjects had significantly lower pain thresholds and more CPM impairment. No significant differences in PPT and CPM were observed between the FM and NPLSR groups. Significant group differences were found in self-reported symptoms of depression, anxiety, stress, and central sensitization. Self-reported symptom severity increased in a stair-step fashion, with the HC group scoring lowest and FM group scoring highest. ConclusionThe NPLSR group manifested CPM dysfunction and pressure hyperalgesia at similar levels to the FM group, indicating that these two chronic pain syndromes, likely based on different pathophysiological mechanisms, in fact share some common pain processing features. However, though both patient groups demonstrated similarities in pain processing, self-reported cognitive-emotional and central sensitization-related symptom severity was significantly higher in the FM cohort, which distinguished them from the chronic NPLSR cohort.

Combined Effects of Shock Wave Therapy and Muscle Energy Technique on Active Trigger Points of the Upper Trapezius Muscle

Objective: We investigated the combined effect of Radial Shockwave Therapy (RSWT) and muscle energy technique (MET) on pain, range of motion (ROM), and neck function in people with active trigger points (ATrPs) of the upper trapezius muscle. Materials &amp; Methods: Fifty-four participants with ATrPs of the upper trapezius muscle were randomly divided into three groups. Group A (n=18) received only MET, group B (n=18) received only RSWT, and group C (n=18) received both RSWT and RSWT. Pain intensity using the Visual Analog Scale (VAS), pressure pain threshold (PPT), neck function using the Neck Disability Index (NDI) questionnaire, and lateral-flexion range of movement (LF ROM) were measured before and after the intervention. The participants were treated for three sessions in one week with at least two days of rest between sessions. Results: All three intervention groups showed pain reduction (p&lt;0.001), an increase in PPT (p&lt;0.001), counter-lateral flexion (CLF) (p&lt;0.001), and also improvement in neck function (p&lt;0.001). The combined group showed a more obvious improvement than the other two groups in PPT (p&lt;0.001). There was no difference between the three groups in terms of VAS and NDI scores and CLF (p&gt;0.05). Conclusion: The results of this study showed that all three interventions used in the upper trapezius trigger points therapy were effective; however, the combined group showed a significant difference in PPT. Therefore, combined therapy is superior to MET and RSWT alone in improving pressure pain relief in individuals with upper trapezius trigger points.

Effects of active scapular correction on cervical range of motion, pain, and pressure pain threshold in patients with chronic neck pain and depressed scapula: a randomized controlled trial

ABSTRACT Background Correction of scapular alignment is advocated as a component for alleviating symptoms for patients with neck pain. Objective The study aimed to examine the effect of active scapular correction on cervical range of motion (ROM), pain, and pressure pain threshold (PPT) in patients with chronic neck pain with depressed scapula. Methods A randomized control trial research design was conducted. Twenty-eight participants with chronic neck pain and depressed scapula were randomly assigned to either the intervention (n = 14) or control (n = 14) group. Active cervical rotation ROM, pain at maximum cervical rotation, and PPT over the upper trapezius muscle region were measured at baseline and post active scapular correction. Results The participants in the intervention group showed significantly greater active cervical rotation ROM and less pain at maximum cervical rotation than the control group, both on the ipsilateral (p < 0.01) and contralateral (p < 0.05) sides of the depressed scapula. No significant difference in PPT between the groups was demonstrated (p = 0.194). Conclusion Active scapular correction intervention resulted in an immediate increase in active cervical rotation ROM and a decrease in neck pain at maximum cervical rotation.

Pressure pain threshold and temporal summation in adults with episodic and persistent low back pain trajectories: a secondary analysis at baseline and after lumbar manipulation or sham

BackgroundPeople with chronic low back pain (LBP) typically have increased pain sensitivity compared to healthy controls, however its unknown if pain sensitivity differs based on LBP trajectory at baseline or after manual therapy interventions. We aimed to compare baseline pressure pain threshold (PPT) and temporal summation (TS) between people without LBP, with episodic LBP, and with persistent LBP, and to compare changes over time in PPT and TS after a lumbar spinal manipulation or sham manipulation in those with LBP.MethodsParticipants were aged 18–59, with or without LBP. Those with LBP were categorised as having either episodic or persistent LBP. PPT and TS were tested at baseline. LBP participants then received a lumbar spinal manipulation or sham, after which PPT and TS were re-tested three times over 30 min. Generalised linear mixed models were used to analyse data.ResultsOne hundred participants (49 female) were included and analysed. There were 20 non-LBP participants (mean age 31 yrs), 23 episodic LBP (mean age 35 yrs), and 57 persistent LBP (mean age 37 yrs). There were no significant differences in PPT or TS between groups at baseline. There was a non-significant pattern of lower PPT (higher sensitivity) from the non-LBP group to the persistent LBP group at baseline, and high variability. Changes in PPT and TS after the interventions did not differ between the two LBP groups.DiscussionWe found no differences between people with no LBP, episodic LBP, or persistent LBP in baseline PPT or TS. Changes in PPT and TS following a lumbar manual therapy intervention do not appear to differ between LBP trajectories.Trial registrationThe trial was prospectively registered with ANZCTR (ACTRN12617001094369).

Pressure pain thresholds in adults with patellofemoral pain and patellofemoral joint osteoarthritis: a case-control study.

Patellofemoral pain (PFP) and patellofemoral joint osteoarthritis (PFJOA) are common non-self-limiting conditions causing significant pain and disability. The underlying pain pathologies lack consensus with evidence suggesting reduced pressure pain thresholds (PPTs) in adolescent females with PFP and individuals with knee osteoarthritis. A paucity of evidence exists for mixed-sex adults with PFP and PFJOA in isolation. Exploring if pain sensitisation is a dominant feature of PFP and PFJOA may have important implications for the delivery of a patient centred management approach. The primary aim was to measure local and remote PPTs in PFP and PFJOA patients compared to matched controls. Secondary aims were to evaluate the relationship between PPTs and (1) condition severity and (2) knee function. 13 PFP patients plus 20 matched controls and 15 PFJOA patients plus 34 matched controls were recruited from a UK mixed-sex adult population. Controls were matched on age, sex and activity level. Demographic details, Tegner activity level score, symptom duration, condition severity (Kujala and KOOS-PF scores for PFP and PFJOA, respectively) and knee function (Modified Whatman score rating of five single leg squats) were recorded. PPTs were measured at six sites: five local around the knee, one remote on the contralateral leg. Between-group differences were tested using a two-way mixed model analysis of variance with repeated measures. Strength of association between PPTs and condition severity and knee function were tested using Spearman's rank order correlation. No statistically significant difference in PPTs were observed between the PFP patients [F(1,31) = 0.687, p = 0.413, η2 = 0.022] or PFJOA patients [F(1,47) = 0.237, p = 0.629, η2 = 0.005] and controls. Furthermore, no correlation was found between PPTs and condition severity or knee function in PFP or PFJOA (p > 0.05). Results suggest mechanical pain sensitisation is not a dominant feature of UK mixed-sex adults with PFP or PFJOA. PFP and PFJOA remain persistent pain complaints which may not be well explained by objective measures of sensitivity such as PPTs. The findings suggest that peripheral pain processing changes leading to pain sensitisation is not a key feature in PFP or PFJOA. Instead the underlying pain pathway is likely to remain primary nociceptive, possibly with a subgroup of patients who experience pain sensitisation and might benefit from a more targeted management approach.

No difference in pressure pain threshold and temporal summation after lumbar spinal manipulation compared to sham: A randomised controlled trial in adults with low back pain

BackgroundChanges in quantitative sensory tests have been observed after spinal manipulative therapy (SMT), particularly in pressure pain thresholds (PPT) and temporal summation (TS). However, a recent systematic review comparing SMT to sham found no significant difference in PPT in patients with musculoskeletal pain. The sham-controlled studies were generally low quality, and conclusions about other quantitative sensory tests could not be made. ObjectivesWe aimed to perform a sham-controlled study with the specific objective of investigating changes in PPT and TS short-term after lumbar SMT compared to sham manipulation in people with low back pain. MethodsThis was a double-blind randomised controlled trial comparing high-velocity low-amplitude lumbar SMT against sham manipulation in participants with low back pain. Primary outcome measures were PPT at the calf, lumbar spine and shoulder, and TS at the hands and feet. These were measured at baseline, then immediately, 15 min and 30 min post-intervention. ResultsEighty participants (42 females) were included in the analyses (mean age 37 years), with 40 participants allocated to each intervention group. Significant between-group differences were only observed for calf PPT, which could be explained by a decrease in PPT (increased sensitivity) after SMT and an increase after sham. Feet TS decreased significantly over time after both SMT and sham, and any other changes over time were inconsistent. ConclusionsOur results suggest that lumbar SMT does not have a short-term hypoalgesic effect, as measured with PPT and TS, when compared to sham manipulation in people with low back pain.

Comparison of a Vibration Roller and a Nonvibration Roller Intervention on Knee Range of Motion and Pressure Pain Threshold: A Randomized Controlled Trial

Roller massage (RM) has become a common intervention among health and fitness professionals. Recently, manufacturers have merged the science of vibration therapy and RM with the development of vibration rollers. Of interest, is the therapeutic effects of such RM devices. The purpose of this study was to compare the effects of a vibration roller and nonvibration roller intervention on prone knee-flexion passive range of motion (ROM) and pressure pain threshold (PPT) of the quadriceps musculature. Forty-five recreationally active adults were randomly allocated to one of 3 groups: vibration roller, nonvibration roller, and control. Each roller intervention lasted a total of 2 minutes. The control group did not roll. Dependent variables included prone knee-flexion ROM and PPT measures. Statistical analysis included parametric and nonparametric tests to measure changes among groups. The vibration roller demonstrated the greatest increase in PPT (180kPa, P < .001), followed by the nonvibration roller (112kPa, P < .001) and control (61kPa, P < .001). For knee flexion ROM, the vibration roller demonstrated the greatest increase in ROM (7°, P < .001), followed by the nonvibration roller (5°, P < .001) and control (2°, P < .001). Between groups, there was a significant difference in PPT between the vibration and nonvibration roller (P = .03) and vibration roller and control (P < .001). There was also a significant difference between the nonvibration roller and control (P < .001). For knee ROM, there was no significant difference between the vibration and nonvibration roller (P = .31). A significant difference was found between the vibration roller and control group (P < .001) and nonvibration roller and control group (P < .001). The results suggest that a vibration roller may increase an individual's tolerance to pain greater than a nonvibration roller. This investigation should be considered a starting point for future research on this technology.

The effect of rigid taping with tension on mechanical displacement of the skin and change in pain perception

ObjectivesTo investigate the effect of rigid taping that induces mechanical displacement of the skin on pain perception. DesignSingle group experiment design with repeated measures. MethodsTwenty-three active healthy volunteers (12 men and 11 women) participated in the study. All participants received three different taping procedures: no tape, taping with tension, and taping without tension. The order of three taping conditions was randomised. Skin displacement was measured during taping with tension. A pressure algometer was used to measure the level of pain perception once before taping, and again after each taping condition, in one testing session. The participants were blind to the values of their pressure pain threshold (PPT) during the experimental period. ResultsThe mean±SD skin displacement in the condition of taping with tension was 2.58±0.49cm. There were significant differences in PPT between taping with tension and taping without tension (mean difference (mean diff)±standard error (SE) 36.43±4.22kPa, p=0.000) and no tape (mean diff±SE 44.31±3.13kPa, p=0.000). No significant difference in PPT between no tape and taping without tension was found (mean diff±SE 7.88±2.83kPa, p=0.067). ConclusionsTaping with tension increases the threshold of pressure pain perception. Therefore, stretch and compression caused by rigid taping with tension could disturb the nociceptive signal transmission and alter pain perception.

Differences in pressure pain threshold among men and women after foam rolling

BackgroundRehabilitation professionals often prescribe foam rolling as an intervention to augment other manual therapies or as a warm-up or recovery after athletic activity. Currently, there is a gap in the literature regarding how foam rolling effects the pressure pain threshold (PPT) among men and women. PurposeThe purpose of this study was to examine the immediate effects of a foam rolling intervention on the ipsilateral agonist, antagonist, and contralateral muscle group PPT among men and women. SettingUniversity kinesiology laboratory. ParticipantsTwenty healthy adults (M = 10, F = 10; mean age = 27.4 ± 8.5 years). Research designPre-test, post-test observational study. InterventionVideo-guided foam roll intervention on the left quadriceps group. Main outcome measuresIpsilateral quadriceps, ipsilateral hamstring, and contralateral quadriceps muscle PPT. ResultsWithin group comparison for men, revealed a statistically significant effect of time on PPT for the left quadriceps (p=<0.001), left hamstring (p = 0.001), and right quadriceps (p=<0.001). For women, there was a statistically significant effect of time on PPT for the left quadriceps (p = 0.001), left hamstring (p = 0.007), and right quadriceps (p=<0.001). No significant difference in PPT between men and women were found for the left quadriceps (p = 0.31), left hamstring (p = 0.13), and right quadriceps (p = 0.070) muscle groups. ConclusionsThese finding suggest that foam rolling can immediately reduce PPT in the ipsilateral agonist, antagonist, and contralateral muscle groups among men and women. Future investigations are needed to determine the long-term effects of foam rolling on PPT among sexes.

Central sensitization and changes in conditioned pain modulation in people with chronic nonspecific low back pain: a case-control study.

Quantitative sensory testing is widely used in human research to investigate the state of the peripheral and central nervous system contributions in pain processing. It is a valuable tool to help identify central sensitization and may be important in the treatment of low back pain. The aim of this study was to evaluate changes in local and segmental hypersensitivity and endogenous pain inhibition in people with chronic nonspecific low back pain. Thirty patients with chronic low back pain and thirty healthy subjects were studied. Pressure pain thresholds (PPTs) were measured from the lumbar region and over the tibialis anterior muscle (TA). A cold pressor test was used to assess the activation of conditioned pain modulation (CPM), and PPTs in the lumbar region were recorded 30s after immersion of participant's foot in a bucket with cold water. People with chronic low back pain have significantly lower PPT than controls at both the lumbar region [89.5kPa (mean difference) 95% CI 40.9-131.1kPa] and TA [59.45kPa (mean difference) 95% CI 13.49-105.42kPa]. During CPM, people with chronic low back pain have significantly lower PPT than controls in lumbar region [118.6kPa (mean difference) 95% CI 77.9-159.2kPa]. Women had significantly lower PPTs than men in both lumbar region [101.7kPa (mean difference) 95% CI 37.9-165.7kPa] and over the TA [189.7kPa (mean difference) 95% CI 14.2-145.2kPa]. There was no significant difference in PPTs in men between healthy controls and those with low back pain, suggesting the significant differences are mediated primarily by difference between women.

Effects of the active release technique on pain and range of motion of patients with chronic neck pain.

[Purpose] To compare the influences of the active release technique (ART) and joint mobilization (JM) on the visual analog scale (VAS) pain score, pressure pain threshold (PPT), and neck range of motion (ROM) of patients with chronic neck pain. [Subjects] Twenty-four individuals with chronic neck pain were randomly and equally assigned to 3 groups: an ART group, a joint mobilization (JM) group, and a control group. Before and after the intervention, the degree of pain, PPT, and ROM of the neck were measured using a VAS, algometer, and goniometer, respectively. [Results] The ART group and JM group demonstrated significant changes in VAS and ROM between pre and post-intervention, while no significant change was observed in the control group. Significant differences in the PPT of all muscles were found in the ART group, while significant differences in all muscles other than the trapezius were found in the JM group. No significant difference in PPT was observed in any muscle of the control group. The posthoc test indicated no statistically significant difference between the ART and JM group, but the differences of variation in VAS, PPT, and ROM were greater in the ART group than in the JM and control groups. [Conclusion] ART for the treatment of chronic neck pain may be beneficial for neck pain and movement.

Reliability and Usefulness of the Pressure Pain Threshold Measurement in Patients with Myofascial Pain

ObjectiveTo assess the usefulness of a pressure algometer to measure pressure pain threshold (PPT) for diagnosis of myofascial pain syndrome (MPS) in the upper extremity and trunk muscles.MethodA group of 221 desk workers complaining of upper body pain participated in this study. Five physiatrists made the diagnosis of MPS using physical examination and PPT measurements. PPT measurements were determined for several muscles in the back and upper extremities. Mean PPT data for gender, side, and dominant hand groups were analyzed. Sensitivity and specificity of Fischer's standard method were evaluated. PPT cut-off values for each muscle group were determined using an ROC curve.ResultsCronbach's alpha for each muscle was very high. The PPT in men was higher than in females, and the PPT in the left side was higher than in the right side for all muscles tested (p<0.05). There was no significant difference in PPT for all muscles between dominant and non-dominant hand groups. Diagnosis of MPS based on Fischer's standard showed relatively high specificity and poor sensitivity.ConclusionThe digital pressure algometer showed high reliability. PPT might be a useful parameter for assessing a treatment's effect, but not for use in diagnosis or even as a screening method.

The Influence of Cranio-cervical Posture on Maximal Mouth Opening and Pressure Pain Threshold in Patients With Myofascial Temporomandibular Pain Disorders

The aim of this study was to assess the influence of cranio-cervical posture on the maximal mouth opening (MMO) and pressure pain threshold (PPT) in patients with myofascial temporomandibular pain disorders. A total of 29 patients (19 females and 10 males) with myofascial temporomandibular pain disorders, aged 19 to 59 years participated in the study (mean years±SD; 34.69±10.83 y). MMO and the PPT (on the right side) of patients in neutral, retracted, and forward head postures were measured. A 1-way repeated measures analysis of variance followed by 3 pair-wise comparisons were used to determine differences. Comparisons indicated significant differences in PPT at 3 points within the trigeminal innervated musculature [masseter (M1 and M2) and anterior temporalis (T1)] among the 3 head postures [M1 (F=117.78; P<0.001), M2 (F=129.04; P<0.001), and T1 (F=195.44; P<0.001)]. There were also significant differences in MMO among the 3 head postures (F=208.06; P<0.001). The intrarater reliability on a given day-to-day basis was good with the interclass correlation coefficient ranging from 0.89 to 0.94 and 0.92 to 0.94 for PPT and MMO, respectively, among the different head postures. The results of this study shows that the experimental induction of different cranio-cervical postures influences the MMO and PPT values of the temporomandibular joint and muscles of mastication that receive motor and sensory innervation by the trigeminal nerve. Our results provide data that supports the biomechanical relationship between the cranio-cervical region and the dynamics of the temporomandibular joint, as well as trigeminal nociceptive processing in different cranio-cervical postures.

The initial effects of different rates of lumbar mobilisations on pressure pain thresholds in asymptomatic subjects

Lumbar mobilisations are commonly used in clinical practice to reduce pain and increase function. Mobilisations to the cervical spine have been shown to reduce pain using pressure pain thresholds (PPTs). Yet there is no evidence to confirm that this happens in the lumbar spine. Furthermore little is known about the effects of different treatment doses on the amount of hypoalgesia produced. It is unknown if changing the rate of application of mobilisations has an effect on hypoalgesia. The aim of this study was to investigate the immediate effects of lumbar posteroanterior mobilisations performed at different rates on PPT and the extent of the hypoalgesia. A repeated measures, single blind, randomised-trial was conducted on 30 asymptomatic subjects. PPTs were measured at 4 sites in the upper and lower quadrants, before and after the application of lumbar posteroanterior mobilisations performed at 2 Hz, 1 Hz and quasi-static. The results demonstrated an immediate and significant improvement in PPT measures ( P = 0.000) irrespective of the rate or site tested. The effects were both local and widespread. There was no significant difference in PPT between the rates of mobilisations. This study provides new experimental evidence that lumbar posteroanterior mobilisations produce an immediate and significant widespread hypoalgesic effect, regardless of the rates of mobilisation in asymptomatic subjects.

The effects of high-velocity low-amplitude thrust manipulation and mobilisation techniques on pressure pain threshold in the lumbar spine

Objective To compare changes in pressure pain threshold (PPT) following spinal high-velocity low-amplitude thrust manipulation (HVLAT) and spinal mobilisation. Design Fifty asymptomatic subjects (mean age 27 (6) years; 29 males and 21 females) volunteered to participate in a randomised controlled, singled blinded design study. Subjects were screened for suitability and were randomly allocated into one of three intervention groups where they received either a unilateral spinal HVLAT or a spinal mobilisation of the lumbar spine, or a sham ‘laser’ procedure (control). PPT measurements were made immediately pre- and post-intervention, using a hand-held algometer which was positioned directly over the lumbar spinous process. A two-way ANOVA with repeated measures was conducted to determine PPT changes between the groups. Statistical significance was set at the 0.05 level. Results There were no significant differences in PPT across time for each of the groups ( P = 0.584). The mobilisation group displayed a small increase, though not a significant change in the mean pressure pain threshold (0.434(0.55) kg/cm 2), although effect size was considered to be large (ES = 0.78). The HVLAT group demonstrated a decrease in the mean PPT (−0.173(0.48)) (ES = 0.36, small), and a smaller decrease was noted for the control group (0.105(0.425) kg/cm 2) (ES = 0.25, small). Conclusion Neither spinal HVLAT nor mobilisation had a significant effect on PPT of the lumbar spine in asymptomatic subjects. Only spinal mobilisation appeared to have a greater mean increase in PPT and effect size than the control group. Further investigation into the hypoalgesic effects of these techniques on symptomatic subjects is suggested.

Experimentally induced muscle pain induces hypoalgesia in heterotopic deep tissues, but not in homotopic deep tissues

The ability of muscle pain to generate somatosensory sensibility changes is controversial. Thus, in the present study, tonic infusion of hypertonic saline (5%, 7.1 ml administered over 15 min) into the tibialis anterior (TA) muscle was used as an experimental model to induce local and referred pain. The sensibility to high-intensity pressure stimuli applied to the local pain area, referred pain area and an arm was assessed in 14 healthy volunteers. Infusion of isotonic (0.9%) saline into the other leg served as control. The subject continuously scored the pain intensity on an electronic visual analogue scale (VAS). Pressure pain threshold (PPT) was determined on the TA muscle (2 cm and 10 cm from the infusion site), at the frontal aspect of the ankle (area of referred pain) and on the arm. To minimise the skin component of the PPT, the skin covering the assessment sites was anaesthetised with an anaesthetic creme. The PPTs were obtained before and after cutaneous analgesia, 1 min and 10 min after infusion start and 10 min after the pain had disappeared. Infusion of hypertonic saline caused significantly ( P<0.05) higher VAS scores than infusion of isotonic saline. A significant ( P<0.04) increase of the PPT (i.e., decreased sensibility) was found at the ankle and on the arm during muscle pain compared to the control condition. No significant differences in PPTs on the TA muscle were found during saline-induced muscle pain compared to the infusion of isotonic saline. The decrease in deep sensibility at the heterotopic sites (referred pain area and arm), but not at homotopic sites (TA muscle), probably reflected the phenomenon of diffuse noxious inhibitory control (DNIC). The inhibitory mechanism during muscle pain was shown to be effective for the deep tissue sensibility in healthy subjects. Thus, a pathologically disturbed inhibitory mechanism may result in widespread deep hyperalgesia in muscle pain patients.