Changes In Pressure Pain Threshold Research Articles

Spinal manipulation does not affect pressure pain thresholds in the absence of neuromodulators: a randomized controlled trial

Background: Measurement of pressure pain threshold (PPT) is a way to determine one of the many potential treatment effects of spinal manipulative therapy.Objective: To determine how multiple spinal manipulations administered in a single-session affected PPTs at local and distal sites in asymptomatic individuals.Methods: Participants were randomly assigned into one of three groups: Group one (n = 18) received a lumbar manipulation followed by a cervical manipulation. Group two (n = 17) received a cervical manipulation followed by a lumbar manipulation. The control group (n = 19) received two bouts of five minutes of rest. At baseline and after each intervention or rest period, each participant’s PPTs were obtained using a handheld algometer. The PPTs were tested bilaterally over the lateral epicondyles of the humerus and over the mid-bellies of the upper trapezius, lumbar paraspinal, and the tibialis anterior muscles. This study was registered with ClinicalTrials.gov, and its Identifier is NCT02828501.Results: Repeated-measures ANOVAs and Kruskal–Wallis tests showed no significant within- or between-group differences in PPT. Within-group effect sizes in the changes of PPT ranged from −.48 at the left paraspinal muscles to .24 at the left lateral humeral epicondyle. Statistical power to detect significant differences at α of 0.05 was calculated to be 0.94.Conclusions: This study suggests that in young adults who do not have current or recent symptoms of spinal pain, multiple within-session treatments of cervical and lumbar spinal manipulation fail to influence PPTs. Changes in PPT that are observed in symptomatic individuals are likely to be primarily influenced by pain-related neuromodulators rather than by an isolated, mechanical effect of spinal manipulation.

Effectiveness of a Treatment Involving Soft Tissue Techniques and/or Neural Mobilization Techniques in the Management of Tension-Type Headache: A Randomized Controlled Trial

ObjectiveTo evaluate the effects of a protocol involving soft tissue techniques and/or neural mobilization techniques in the management of patients with frequent episodic tension-type headache (FETTH) and those with chronic tension-type headache (CTTH). DesignRandomized, double-blind, placebo-controlled before and after trial. SettingRehabilitation area of the local hospital and a private physiotherapy center. ParticipantsPatients (N=97; 78 women, 19 men) diagnosed with FETTH or CTTH were randomly assigned to groups A, B, C, or D. Interventions(A) Placebo superficial massage; (B) soft tissue techniques; (C) neural mobilization techniques; (D) a combination of soft tissue and neural mobilization techniques. Main Outcomes MeasuresThe pressure pain threshold (PPT) in the temporal muscles (points 1 and 2) and supraorbital region (point 3), the frequency and maximal intensity of pain crisis, and the score in the Headache Impact Test-6 (HIT-6) were evaluated. All variables were assessed before the intervention, at the end of the intervention, and 15 and 30 days after the intervention. ResultsGroups B, C, and D had an increase in PPT and a reduction in frequency, maximal intensity, and HIT-6 values in all time points after the intervention as compared with baseline and group A (P<.001 for all cases). Group D had the highest PPT values and the lowest frequency and HIT-6 values after the intervention. ConclusionsThe application of soft tissue and neural mobilization techniques to patients with FETTH or CTTH induces significant changes in PPT, the characteristics of pain crisis, and its effect on activities of daily living as compared with the application of these techniques as isolated interventions.

The effects of total knee replacement and non-surgical treatment on pain sensitization and clinical pain.

The objective was to compare the effect of total knee replacement (TKR) followed by a 3-month non-surgical treatment with the non-surgical treatment alone in reducing pain sensitization and other pain-related measures in patients with knee osteoarthritis. One hundred patients were randomized to (1) TKR followed by a non-surgical treatment of neuromuscular exercise, education, diet, insoles and pain medication or (2) the non-surgical treatment alone. Outcomes assessed at baseline and after 3months were as follows: (1) pain sensitization assessed as pressure-pain thresholds (PPTs) at the knee (localized sensitization) and the lower leg (spreading sensitization), (2) peak pain intensity during the previous 24h, (3) pain intensity after 30min of walking, (4) pain location and pattern, (5) spreading of pain on a region-divided body chart and (6) the usage of pain medication. There was a statistical significant mean difference (95% CI) in change in PPTs from baseline to 3months between groups in the crude analysis of 71kPa (21-121) and of 75kPa (33-117) when adjusting for baseline PPT, age, gender and body mass index, favouring the group having TKR. There were no significant between-group differences in change in the pain-related measures from baseline to 3months (p=0.15-0.27). Both groups improved in most of the pain-related measures (p<0.05). At 3months, TKR followed by non-surgical treatment is more effective in reducing localized and spreading pain sensitization than non-surgical treatment alone. Both treatments are equally efficacious in reducing the pain-related measures of this study. WHAT DOES THIS STUDY ADD?: Knee replacement followed by non-surgical treatment is more effective in reducing pain sensitization, but not other pain-related measures, as compared to non-surgical treatment alone at 3months.

Exercise- and Stress-Induced Hypoalgesia in Musicians with and without Shoulder Pain: A Randomized Controlled Crossover Study

Professional and pre-professional musicians are characterized by physical and psychological demands inherent to their musical activity, and therefore at risk for developing performance related musculoskeletal pain. Physical and psychological demands are known to influence human pain modulation. In this study we compared the influence of a physically and emotionally stressful task on pain thresholds in musicians with and without shoulder pain. A single-blinded randomized and controlled crossover study design was used to compare the effects of a physical versus emotional testing procedure on pressure pain thresholds (PPTs) in musicians with and without shoulder pain. All data were obtained in the field (e.g., at the physiotherapy accommodation in the Royal Conservatory). During the physical testing procedure, the subjects performed an isometric exercise of the glenohumeral external rotators. The emotional task comprised watching "unpleasant" images selected from the International Affective Picture System. The outcome was the assessment of change in PPTs before and after the physical and emotional task. Our results indicate similar effects of both protocols in either group, i.e., musicians with and without shoulder pain (P > 0.05). All musicians showed elevated PPTs at local and remote areas after isometric exercise (P < 0.05). The emotional stress task increased PPTs at remote areas only (P < 0.05). Despite the small sample size of musicians without shoulder pain, a power of 78.5% was achieved to detect the necessary effect size of Cohen's d = 1. Furthermore, comparing these results with those of non-musicians (both healthy subjects and patients with shoulder pain) might reveal information regarding the specific adaptations. Finally a high variability was observed in shoulder disability (i.e., SDQ-scores) as typically seen in a population with shoulder pain. In musicians with and without regional shoulder pain, no significant differences were found with respect to pain modulation during a physically and an emotionally stressful task. Both interventions adequately activated central and widespread pain inhibitory mechanisms in both groups.

Pulsed electromagnetic fields in knee osteoarthritis: a double blind, placebo-controlled, randomized clinical trial.

Objectives. This trial aimed to test the effectiveness of a wearable pulsed electromagnetic fields (PEMF) device in the management of pain in knee OA patients.Methods. In this randomized [with equal randomization (1:1)], double-blind, placebo-controlled clinical trial, patients with radiographic evidence of knee OA and persistent pain higher than 40 mm on the visual analog scale (VAS) were recruited. The trial consisted of 12 h daily treatment for 1 month in 60 knee OA patients. The primary outcome measure was the reduction in pain intensity, assessed through VAS and WOMAC scores. Secondary outcomes included quality of life assessment through the 36-item Medical Outcomes Study Short-Form version 2 (SF-36 v2), pressure pain threshold (PPT) and changes in intake of NSAIDs/analgesics.Results. Sixty-six patients were included, and 60 completed the study. After 1 month, PEMF induced a significant reduction in VAS pain and WOMAC scores compared with placebo. Additionally, pain tolerance, as expressed by PPT changes, and physical health improved in PEMF-treated patients. A mean treatment effect of −0.73 (95% CI − 1.24 to − 0.19) was seen in VAS score, while the effect size was −0.34 (95% CI − 0.85 to 0.17) for WOMAC score. Twenty-six per cent of patients in the PEMF group stopped NSAID/analgesic therapy. No adverse events were detected.Conclusion. These results suggest that PEMF therapy is effective for pain management in knee OA patients and also affects pain threshold and physical functioning. Future larger studies, including head-to-head studies comparing PEMF therapy with standard pharmacological approaches in OA, are warranted.Trial registration: ClinicalTrials.gov, http://www.clinicaltrials.gov, NCT01877278

Immediate effects of thoracic spinal mobilisation on erector spinae muscle activity and pain in patients with thoracic spine pain: a preliminary randomised controlled trial

ObjectivesTo investigate the activity of the thoracic erector spinae muscles and perceived pain intensity immediately after central postero-anterior (PA) mobilisation of the thoracic spine. DesignRandomised, placebo-controlled, experimental design. Participants and interventionsThirty-four participants with non-specific thoracic pain were randomised to the experimental group [grade III central PA mobilisation performed for 3minutes at the level of the seventh thoracic vertebra (T7)] or the placebo group (less than grade I central PA mobilisation performed for 3minutes at T7). Main outcome measuresBefore and immediately after PA mobilisation, surface electromyography (EMG) was recorded from the thoracic erector spinae muscles as the participants performed 10° spine extension from a prone position for 10seconds. Each participant rated their pain intensity as an investigator performed grade III central PA over the most symptomatic thoracic segment, and the pressure pain threshold (PPT) was evaluated bilaterally over the erector spinae muscles. ResultsThe EMG amplitude of thoracic erector spinae activity was reduced significantly after the intervention in the experimental group (P<0.05), but not in the placebo group. The difference between the groups was significant {pre–post change: placebo −14 [standard deviation (SD) 50]mV, experimental 28 (SD 48)mV; mean difference −42mV; 95% confidence interval of the difference −76 to 7; P<0.05} albeit small (Grissom=0.44). However, both groups showed a significant reduction in pain immediately after the intervention, and both groups showed a similar pre–post change in PPT. ConclusionThese preliminary findings indicate that grade III central mobilisation over the most symptomatic thoracic segment reduces thoracic erector spinae activity during extension of the trunk in people with non-specific thoracic spine pain. Clinical trial registration numberISRCTN47601528.

Acupuncture-induced changes of pressure pain threshold are mediated by segmental inhibition--a randomized controlled trial.

Our aim was to distinguish between spinal and supraspinal mechanisms in the intact nervous system by comparing homosegmental and heterosegmental effects of electroacupuncture (EA) and manual acupuncture (MA) on sensory perception in healthy volunteers by means of quantitative sensory testing. Seventy-two healthy volunteers were randomly assigned to receive either MA or EA at SP 6, SP 9, GB 39, and ST 36 at the left leg or relaxed for 30 minutes (control group [CG]). Blinded examiners assessed 13 sensory modalities (thermal and mechanical detection and pain thresholds) at the upper arms and lower legs before and after intervention by means of a standardized quantitative sensory testing battery. Change scores of all 13 sensory thresholds were compared between groups. The main outcome measure was the change score of the pressure pain threshold (PPT). There were no baseline differences between groups. Pressure pain threshold change scores at the lower left leg, in the same segment as the needling site, differed significantly (P = 0.008) between the EA (median: 103.01 kPa) and CG groups (median: 0.00 kPa) but not between the MA (median: 0.00 kPa) and CG groups. No further significant change score differences were found between one of the acupuncture groups and the CG. The PPT can be changed by EA. The PPT increase was confined to the segment of needling, which indicates that it is mainly mediated by segmental inhibition in the spinal cord. This underscores the importance of segmental needling and electrical stimulation in clinical practice.

Comparison of Hypoalgesic Effects of Neural Stretching vs Neural Gliding: A Randomized Controlled Trial

ObjectiveThe purpose of this study was to evaluate the immediate mechanical hypoalgesic effect of neural mobilization in asymptomatic subjects. We also compared neural gliding vs neural stretching to see which produced greater hypoalgesic effects in asymptomatic subjects. MethodsForty-five asymptomatic subjects (20 men and 25 women; mean ± SD age, 20.8 ± 2.83 years) were randomly allocated into 3 groups: the neural glide group, the neural stretch group, and the placebo group. Each subject received 1 treatment session. Outcome measures included bilateral pressure pain threshold measured at the trigeminal, cervical, and tibialis anterior points, assessed pre-treatment and immediately post-treatment by a blinded assessor. Three-way repeated-measures analysis of variance was used to evaluate changes in pressure pain threshold, with group (experimental or control) as the between-subjects variable and time (pre-, post-treatment) or side (dominant, nondominant) as the within-subjects variable. ResultsGroup differences were identified between neural mobilization groups and the placebo group. Changes occurred in all of the pressure pain threshold measures for neural gliding, and in all but the trigeminal point for neural stretch. No changes in the pressure pain threshold measures occurred in the placebo group. ConclusionsThis research provides new experimental evidence that neural mobilization produces an immediate widespread hypoalgesic effect vs placebo but neural gliding produces hypoalgesic effects in more body sites than neural stretching.

Skin impedance is not a factor in transcutaneous electrical nerve stimulation effectiveness.

ObjectiveTranscutaneous electrical nerve stimulation (TENS) is a nonpharmacological intervention used to manage pain using skin surface electrodes. Optimal electrode placement is unclear. We hypothesized that better analgesia would occur if electrodes were placed over sites with lower skin impedance. Optimal site selection (OSS) and sham site selection (SSS) electrode sites on the forearm were identified using a standard clinical technique.MethodsExperiment 1 measured skin impedance in the forearm at OSS and SSS. Experiment 2 was a crossover design double-blind randomized controlled trial comparing OSS-TENS, SSS-TENS, and placebo TENS (P-TENS) to confirm differences in skin impedance between OSS and SSS, and measure change in pressure pain threshold (PPT) following a 30-minute TENS treatment. Healthy volunteers were recruited (ten for Experiment 1 [five male, five female] and 24 for Experiment 2 [12 male, 12 female]). TENS was applied for 30 minutes at 100 Hz frequency, 100 µs pulse duration, and “strong but nonpainful” amplitude.ResultsExperiment 1 results demonstrate significantly higher impedance at SSS (17.69±1.24 Ω) compared to OSS (13.53±0.57 Ω) (P=0.007). For Experiment 2, electrode site impedance was significantly higher over SSS, with both the impedance meter (P=0.001) and the TENS unit (P=0.012) compared to OSS. PPT change was significantly greater for both OSS-TENS (P=0.024) and SSS-TENS (P=0.025) when compared to P-TENS. PPT did not differ between the two active TENS treatments (P=0.81).ConclusionSkin impedance is lower at sites characterized as optimal using the described technique of electrode site selection. When TENS is applied at adequate intensities, skin impedance is not a factor in attainment of hypoalgesia of the forearm in healthy subjects. Further investigation should include testing in patients presenting with painful conditions.

A randomised placebo-controlled study investigating the effects of mobilisation treatment duration on pain in participants with chronic low back pain

Background: A common treatment used by physiotherapists for patients with low back pain is mobilisation. The aim of applying mobilisation treatment is to increase range of movement and reduce pain and stiffness. Therapists choose a specific dose of mobilisation for each patient, which includes a decision on the duration of applied force, commonly up to 3minutes. Little research has been done to determine the effects of different durations of treatment. There is tentative evidence that increased duration beyond 3minutes leads to a decrease in pain. Purpose: This study aimed to establish the analgesic effects of short and long durations of lumbar mobilisation treatment. Methods: A randomised placebo controlled trial was conducted to establish the immediate and short-term (24hours after treatment) analgesic effects of different duration of lumbar mobilisation in participants with LBP. Comparisons of pressure pain threshold (PPT), verbal rating scale (VRS) of pain were made immediately after a placebo-control intervention and 2minutes of mobilisation treatment, and immediately and 24-hours after 1 and 6minutes of mobilisation treatment. Results: Analysis of treatment responders demonstrated that significantly more participants receiving longer duration of treatment experienced a reduction in PPT local to the site of treatment (p=.001). Overall, there was no significant difference between treatment groups. Verbal rating of pain on movement was significantly reduced after treatment (p<.01) but the difference between treatment groups did not reach significance. There was dissociation between participants’ verbal rating of pain and PPT. Treatment force had a significant mediating effect on pain (p=.01), with greater treatment forces resulting in greater pain reduction local to the site of treatment. Conclusion(s): This study highlighted the varying response of participants to lumbar mobilisation treatment. The difference is response levels and mediating effect of force on PPT were evident local to the site of treatment and not at more distant locations, suggesting that changes in PPT were mediated by a local analgesic mechanism. The dissociation between changes in PPT and verbal rating of pain imply these measures of pain are mediated by different underlying neurobiological mechanisms. Implications: These findings suggest that where pain allows, applying mobilisations for longer and with greater force may result in a greater analgesic effect. The dissociation between PPT and verbal ratings of pain in this study suggest that when investigating the analgesic effects of treatment, it may be important to incorporate a number of pain measures in order to gain wide appreciation of change in pain felt by patients.

(474) Skin impedance is not a factor in TENS analgesia

Transcutaneous Electrical Nerve Stimulation (TENS) is a non-pharmacological intervention used to manage pain using skin surface electrodes. Optimal electrode placement is unclear. We hypothesized that better analgesia would occur if electrodes were placed over sites with lower skin impedance. Optimal (OSS) and sham (SSS) electrode sites on the forearm were identified using a standard clinical technique. Experiment 1 measured skin impedance in the forearm at OSS and SSS to determine the relationship between electrode site and skin impedance. Experiment 2 was a crossover design double-blind RCT comparing OSS TENS, SSS TENS and Placebo TENS (P-TENS) to confirm differences in skin impedance between OSS and SSS and to measure change in Pressure pain threshold (PPT) following a 30 minute TENS treatment. Healthy volunteers were recruited (10 for experiment 1 (5 male, 5 female) and 24 for experiment 2 (12 male, 12 female). TENS was applied for 30 minutes at 100 Hz frequency, 100 μs pulse duration, and at a “strong and non-painful” amplitude. Experiment 1 results demonstrate significantly higher impedance at SSS (17.69±1.24Ω) compared to OSS (13.53±.57Ω) (p=.007). For experiment 2, electrode site impedance was significantly higher over SSS as measured by both an impedance meter (p=.001) and the TENS unit (p=0.012) when compared to OSS. PPT change was significantly greater for both OSS-TENS (p=0.024) and SSS-TENS (p=0.025) when compared to P-TENS. PPT did not differ between the two active TENS treatments (p=0.81). Skin impedance is lower at sites characterized as optimal using the described technique of electrode site selection. When TENS is applied at adequate intensities, skin impedance is not a factor in attainment of hypoalgesia of the forearm in healthy subjects. Further investigation should include testing in patients presenting with painful conditions.

Effects of two different intensities of transcutaneous electrical nerve stimulation on pain thresholds of contralateral muscles in healthy subjects.

[Purpose] This study aimed to investigate the differential effects of high-intensity and low-intensity transcutaneous electrical nerve stimulation on the contralateral side on the pain threshold in healthy subjects. [Subjects and Methods] Twenty-five healthy adults, volunteers received two intensity levels (motor-level, 1.5 times the muscle motor threshold; sensory-level, sensory threshold of the common peroneal nerve), for 30 s on separate days. Pressure pain threshold was recorded on the contralateral tibialis anterior and deltoid muscle before, during, and after stimulation. [Results] Motor-level stimulation significantly increased the pressure pain threshold at both muscle sites, while effects of sensory-level stimulation on pressure pain thresholds were significant only at the deltoid site. The percent change in pressure pain thresholds at both sites was significantly higher during motor-level stimulation. [Conclusion] Motor-level stimulation, applied unilaterally to one leg, produced immediate contralateral diffuse and segmental analgesic effects. This may be of therapeutic benefit in patients for whom transcutaneous electrical nerve stimulation cannot be directly used at the painful site.

A New Real-time Method for Detecting the Effect of Fentanyl Using the Preoperative Pressure Pain Threshold and Narcotrend Index

Individual variability in the effects of opioid analgesics such as fentanyl remains a major challenge for tailored pharmacological treatment including postoperative analgesia. This study aimed to establish a new real-time method for detecting the effects of fentanyl and their individual differences in the preoperative period, using the pressure pain threshold (PPT) and Narcotrend index (NTI) test.Eighty women undergoing elective surgery under general anesthesia were enrolled in this randomized, double-blinded, placebo-controlled study to receive either intravenous fentanyl (Group F) or saline (Group S). Before (T1) and 5 (T2) and 10 min (T3) after intravenous injection, the PPT, NTI, respiratory rate, heart rate, blood pressure, and pulse oxygen saturation were measured. The initial time at which the Narcotrend index showed a decline was also recorded.In total, 40 patients in Group S and 38 patients in Group F were included in the final analysis. At 5 min and 10 min after intravenous fentanyl administration, the analgesic effect was determined by measuring the PPT, which was significantly increased (P < 0.001), and the sedative effect was detected using the NTI, which was significantly decreased (P < 0.001). The distribution of percentage changes of the PPT and NTI showed individual differences. At T2 and T3, the absolute changes in NTI and PPT were positively correlated (r = 0.444 at T2, P = 0.005; r = 0.332 at T3, P = 0.042).Through the PPT and NTI, it was feasible to easily detect the effects of fentanyl and their individual differences in real time before induction of anesthesia in the operation room. This method could potentially be applied to preoperatively determine patients’ sensitivity to fentanyl.

Gender Differences in Pressure Pain Thresholds during Sustained Jaw Muscle Contraction

Purpose: To determine whether a fatiguing clench significantly affects the changes in pressure pain threshold (PPT) in men compared to women. Methods: The changes of PPTs from before to after a sustained clench in 12 men and 12 women were obtained. We used a decrease in median frequencies of surface electromyography (EMG) power spectra from the start to the end of the sustained clench as evidence of fatigue. Endurance time for the clench was used as a covariate. Results: The median frequencies decreased after the clench in both the anterior temporalis and masseter muscles, did not differ with the muscle or the gender of the subjects, and none of the interaction terms were significant. The PPTs were lower for women for both muscles, were decreased after the sustained clench, but failed to show the hypothesized gender by time interaction. Conclusions: Our results show that women have lower PPTs than men, but do not respond differently than men to jaw muscle fatigue.

Immediate changes in pressure pain sensitivity after thoracic spinal manipulative therapy in patients with subacromial impingement syndrome: A randomized controlled study

BackgroundThoracic SMT can improve symptoms in patients with subacromial impingement syndrome. However, at this time the mechanisms of SMT are not well established. It is possible that changes in pain sensitivity may occur following SMT. ObjectivesTo assess the immediate pain response in patients with shoulder pain following thoracic spinal manipulative therapy (SMT) using pressure pain threshold (PPT), and to assess the relationship of change in pain sensitivity to patient-rated outcomes of pain and function following treatment. DesignRandomized Controlled Study. MethodsSubjects with unilateral subacromial impingement syndrome (n = 45) were randomly assigned to receive treatment with thoracic SMT or sham thoracic SMT. PPT was measured at the painful shoulder (deltoid) and unaffected regions (contralateral deltoid and bilateral lower trapezius areas) immediately pre- and post-treatment. Patient-rated outcomes were pain (numeric pain rating scale – NPRS), function (Pennsylvania Shoulder Score – Penn), and global rating of change (GROC). ResultsThere were no significant differences between groups in pre-to post-treatment changes in PPT (p ≥ 0.583) nor were there significant changes in PPT within either group (p ≥ 0.372) following treatment. NPRS, Penn and GROC improved across both groups (p < 0.001), but there were no differences between the groups (p ≥ 0.574). ConclusionThere were no differences in pressure pain sensitivity between participants receiving thoracic SMT versus sham thoracic SMT. Both groups had improved patient-rated pain and function within 24–48 h of treatment, but there was no difference in outcomes between the groups.

Pressure pain threshold and visual analogue scale changes in the high and low energy extracorporeal shock wave

Objective: This study aims to investigate high energy and low energy extracorporeal shockwave therapy (ESWT) and which one is more effective for shoulder pain. Design: Single blind randomized controlled trial. Methods: Fifty two subjects with upper trapezius (UT) trigger point (TrP) participated in this study. They were allocated to high energy (n=26) and low energy group (n=26). This study applies ESWT and investigates the changes of pressure pain threshold (PPT) and visual analogue scale (VAS). The high and low energy groups received focused piezo electric type ESWT 4 Hz, 1,000 pulses and 0.351 and 0.092 mJ/mm2 respectively. Outcome measures of PPT and pain was measured by algometer and pain VAS. These measurements were performed before and after treatment. Results: The PPT value was significantly increased in both groups after treatment (p<0.05) and VAS scores were significantly decreased after treatment in both groups (p<0.05). However, there were no significant differences between groups. Conclusions: ESWT is an effective treatment for the application of the UT TrP. Although there were significant effects of extracorporeal shock wave therapy on PPT and VAS scores, there were no signficant differences between high and low energy extracorporeal shock wave therapy.

Changes in electrical pain threshold of fascia and muscle after initial and secondary bouts of elbow flexor eccentric exercise.

This study investigated changes in electrical pain threshold (EPT) after repeated eccentric exercise bouts to test the hypothesis that fascia would become more sensitive than muscle when greater delayed onset muscle soreness (DOMS) is induced. Ten young men performed two eccentric exercise bouts (ECC1, ECC2) consisting of ten sets of six maximal isokinetic eccentric contractions of the elbow flexors with the same arm separated by 4 weeks. Maximal voluntary isometric contraction torque, range of motion, muscle soreness assessed by a visual analogue scale (VAS) and pressure pain threshold (PPT) were measured before, immediately after and 1-5 days after exercise. EPT was assessed in the biceps brachii fascia (BBF), biceps brachii muscle, and brachialis fascia (BF) 1 day before, immediately after, and 1, 2 and 4 days after exercise. All measures showed smaller changes (P < 0.05) after ECC2 than ECC1. EPT decreased after both bouts and the largest decreases were evident at 2 days post-exercise (P < 0.05). The decreases in EPT after ECC1 were greater (P < 0.05) for both BBF (Baseline: 1.45 ± 0.23 mA, 2 days post-exercise: 0.13 ± 0.11 mA) and BF (1.64 ± 0.29 mA, 0.26 ± 0.2 mA) than muscle (1.56 ± 0.29 mA, 0.69 ± 0.33 mA). Changes in EPT were correlated with the changes in PPT (r = 0.63-0.87, P ≤ 0.05) but not with VAS (r = -0.01 to 0.50). These results show that fascia becomes more sensitive than muscle to electrical stimulation after the initial eccentric exercise, suggesting that damage inflammation to fascia than muscle fibres is more associated with DOMS.

Influence of different frequencies of transcutaneous electrical nerve stimulation on the threshold and pain intensity in young subjects.

Objective To investigate the effects of different transcutaneous electrical nerve stimulation frequencies in nociception front of a pressure pain threshold and cold in healthy individuals.Methods Twenty healthy subjects were divided into four groups, all of which have gone through all forms of electrical stimulation at different weeks.Assessments were pre and post-therapy, 20 and 60 minutes after stimulation. To evaluate the pressure pain threshold, an algometer was used with one tapered tip, pressing the hypothenar region until voluntary report the word “pain”. Cold pain intensity was assessed by immersion in water at 5°C for 30 seconds; at the end, the subject was asked to quantify the pain intensity on a Visual Analog Scale for Pain. For electrical stimulation, two electrodes were used near the elbow, for 20 minutes, with an intensity strong, but not painful. The frequency was in accordance with the group: 0Hz (placebo); 7Hz; 100Hz; and 255Hz.Results Both for the assessment of pressure pain threshold as the cold pain intensity, there was no significant difference (p>0.05).Conclusion We conclude that the use of transcutaneous electrical nerve stimulation on dermatomes C6 to C8 produced no significant change in pressure pain threshold or cold discomfort.

Pressure pain sensitivity changes after use of shock-absorbing insoles among young soccer players training on artificial turf: a randomized controlled trial.

Prospective, randomized, controlled single-blind intervention trial. Shock-absorbing insoles (SAIs), compared with usual insoles, were hypothesized to result in larger increases in pressure pain threshold (PPT) after 3 weeks of use. Shock-absorbing insoles can decrease self-reported pain among young soccer players training on artificial turf. However, nothing is known about the underlying changes in pain sensitivity assessed by PPT. Methods Seventy-five players were included from the youth teams of under 15, under 17, and under 19 years of age, playing for the Aalborg Boldspilklub (AaB) professional sports club. After a randomization stratified by team and age, players were divided into 2 groups, one that received SAIs and a control group that used their usual insoles. Assessments were made in both groups after 3 weeks of training on artificial turf (baseline) and 3 weeks later (follow-up). The primary outcome was change in PPTs from baseline to follow-up, with PPTs measured over 13 locations on the plantar surface of the foot, leg, and low back of the nonpreferred kicking leg. A significantly larger increase was found in PPTs from baseline to follow-up for the SAI group compared with the control group (mean difference, 62 kPa; 95% confidence interval [CI]: 40, 85 kPa). The PPTs increased significantly more among the SAI group compared with the control group (P<.05) for the abductor digiti minimi (mean difference, 82 kPa; 95% CI: 6, 157 kPa), tibialis anterior (mean difference, 125 kPa; 95% CI: 20, 230 kPa), medial gastrocnemius (mean difference, 83 kPa; 95% CI: -6, 171 kPa), and erector spinae (mean difference, 86 kPa; 95% CI: -17, 188 kPa). The use of SAIs resulted in increased PPTs after 3 weeks of training on artificial turf compared with controls, suggesting a protective role of SAIs in pressure sensitivity and pain perception.

The immediate effects of thoracic transverse mobilization in patients with the primary complaint of mechanical neck pain: a pilot study

Objective:Posterior-to-anterior (PA) vertebral mobilization to the thoracic spine has been studied as an intervention for neck pain. Our purpose was to explore effects of a different mobilization technique, transverse vertebral pressure, on cervical range of motion (ROM) and pain when applied to the thoracic spine among participants with neck pain.Methods:A single-blinded quasi-experimental study with a one-group pretest–posttest design. A transverse group consisted of 21 participants whose neck pain increased with active movements. A non-intervention group of 20 asymptomatic participants was included simply to ensure rater blinding. The treatment group received Grades IV to IV+ transverse mobilizations at T1 through T4 bilaterally. Measurements taken immediately after intervention included pre/post cervical ROM, distant pressure pain threshold (PPT), and a numerical pain rating scale (NPRS). Analysis utilized t-tests and ordinal counterparts.Results:The transverse group demonstrated significant gains in extension and bilateral rotation (P≤0·005) but not flexion or side-bend. A total of 57% of mobilized participants reported clinically meaningful decreased pain (P<0·001). Seven participants exceeded the PPT MDC95 of 0·36 kg/cm2. The non-intervention group had no significant changes in ROM or NPRS scores.Discussion:After 8 minutes of transverse mobilization to the upper thoracic spine, significant gains in cervical extension and bilateral rotation, and decreased pain scores were found. There were no adverse effects. Unlike other mobilization studies, PPT changes at a remote site were statistically but not clinically meaningful. Findings suggest that transverse mobilization would be a productive topic for controlled clinical trials.