Pressure Algometry Research Articles

Técnica de microindentación ósea y algometría de presión aplicada al recambio protésico de rodilla y dolor en punta de vástago tibial. Resultados preliminares en un grupo de 20 pacientes

ObjectivesTo study the relationship between the appearance of end-of-stem pain with a preoperative decrease in local bone strength by using the bone microindentation technique. The potential usefulness of pressure algometry in the diagnosis and monitoring of this group of patients is also determined. Material and methodA preliminary intra- and inter-rater correlation study was performed in a group of 50 healthy volunteers in order to validate the algometry technique. A prospective study was then conducted on 20 patients with a mean age of 74 years (range 57-84) undergoing knee prosthetic surgery with use of a cementless tibial stem. Bone microindentation and pressure algometry measurements were made preoperatively, and after one year of follow-up. The statistical analysis was performed using the Intraclass correlation coefficient and the Student t test for paired data. ResultsThe intra and inter-rater correlation values were excellent; 0.91 (0.84-0.95) and 0.86 (0.74-0.92), respectively. No significant variations were found in the microindentation (P=.11) or in the pressure algometry (P=.6) values after one year of follow-up. Nevertheless, a significant correlation was observed between the values for pressure algometry and the EVA (P=.002) and functional scale (P=.02) at the end of follow-up. ConclusionsPressure Algometry is a useful tool to evaluate this group of patients. Bone microindentation does not seem to be useful in identifying patients with increased risk of developing tibial end-of-stem pain.

Pressure pain threshold of the cervico‐facial muscles in healthy elderly people: the role of gender, age and dominance

The aim of this study was to assess the impact of age on pressure pain threshold (PPT) of cervico-facial muscles in healthy geriatric subjects and to investigate the role of gender and dominance on nociception. Musculo-skeletal pain is common in the elderly, but being subjective, it risks to be underdiagnosed and undertreated. A useful method for assessment of local pain is determining PPT through pressure algometry. Ageing process seems to increase PPTs, but reference values for the assessment of pain in geriatric subjects are lacking. In this study, PPTs in temporal muscle, masseter, sternocleidomastoid, occipital and splenius capitis of 97 healthy elderly subjects were measured using Fischer algometer. Participants were divided by age in four classes (years 65-69; 70-74; 75-79; ≥80). Women had lower PPTs in all muscles compared with men. Comparing PPTs obtained from the right and the left side, no significant differences were recorded neither in men nor in women. When dividing subjects by age class and education, in both genders no significant differences were observed in PPTs among the groups, neither in the right nor in the left sides. In conclusion, the present study reports reference PPT values for the cervico-facial muscles that can be applied to a population of healthy elderly subjects. After 65 years of age, further ageing does not influence PPTs in cervico-facial muscles whereas female gender has lower PPTs.

Pain threshold and intensity in rheumatic patients: correlations with the Hamilton Depression Rating scale

Individuals suffering from chronic pain are frequently affected by depression, which in turn increases the risk of developing chronic pain over time. This study aims to investigate the relationship between depression and pain intensity and threshold in a group of rheumatic patients compared to healthy subjects. One hundred twenty-four individuals of whom 50 were affected by rheumatoid arthritis (RA), 23 by psoriatic arthritis (PsA), 23 by ankylosing spondylitis (AS), and 28 age-matched controls without chronic pain underwent quantitative sensory testing to assess pressure pain threshold with pressure algometry. Pain intensity was evaluated through the visual analogue scale (VAS) and depression through the Hamilton Depression Rating scale (HAMD). A significant inverse correlation between HAMD values and pressure pain thresholds was found in the entire group of patients (p < 0.0001), in controls (p = 0.02), and also in RA (p = 0.002), PsA (p < 0.0002), and AS (p = 0.02) patients when analyzed separately, while no significant correlation was found between HAMD and VAS values or pressure pain thresholds and VAS. We found lower pain thresholds in RA and PsA patients while no difference has been evidenced in AS patients compared to healthy controls. HAMD scores were also significantly higher in rheumatic patients than in controls. The use of pressure algometry in the evaluation of chronic pain in patients affected by rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis that display comorbid depression could represent an additional and integrative method to improve pain/depression overlap management or research.

Quantitative sensory testing and pain tolerance in patients with mild to moderate Alzheimer disease compared to healthy control subjects

Patients with Alzheimer disease (AD) report pain less frequently than their cognitively intact peers. It has been hypothesized that pain processing is altered in AD. The aim of this study was to investigate agreement and reliability of 3 pain sensitivity tests and to examine pain threshold and tolerance in patients with AD. We examined 29 patients with mild to moderate AD and 29 age- and gender-matched healthy control subjects with quantitative sensory testing, ie, assessments of detection threshold (warmth detection threshold [WDT]) and pain threshold (heat pain threshold [HPT], pressure algometry, cold pressor test), and assessments of tolerance (pressure algometry, cold pressor test). All procedures were done twice on day 1, 1hour apart, and repeated on day 2. We found no difference between groups for WDT (patient vs control subjects: mean [95% confidence interval]: 35.5°C [33.4°C to 37.6°C] vs 35.4°C [34.3°C to 36.5°C], P=.8) or HPT (41.2°C [40.0°C to 42.4°C] vs 42.3°C [41.1°C to 43.5°C], P=.24). We observed comparable thresholds for pressure algometry (median [25% to 75% interquartile range]: 120kPa [100 to 142kPa] vs 131kPa [113 to 192kPa], P=.10), but significantly lower tolerance in AD patients (213kPa [188 to 306kPa] vs 289kPa [262 to 360kPa], P=.008). No differences were found for the cold pressor test. The study demonstrated good replicability of the sensory testing data with comparable data variability, for both groups, which supports the use of these methods in studies of patients with mild to moderate AD. Contrary to previous studies, we observed a reduced pain tolerance in patients with mild to moderate AD, which suggests that the reduced report of pain cannot be explained by reduced processing of painful stimuli.

Intraexaminer and Interexaminer Reliability of Manual Palpation and Pressure Algometry of the Lower Limb Nerves in Asymptomatic Subjects

ObjectiveNerve palpation is a method of clinically identifying mechanosensitivity of neural tissue by means of pressure algometry and manual palpation. There are few investigations of the reliability of lower limb nerve palpation, and femoral nerve palpation has never been previously reported. The aim of this study was to investigate the reliability of nerve palpation of the femoral, sciatic, tibial, and common peroneal nerves and to report normative values for the femoral nerve. MethodsThe 4 lower limb nerves were palpated in 39 healthy volunteers using pressure algometry and manual digital palpation. Measurements were taken twice by 1 rater (intrarater reliability) and once by a second rater (interrater reliability). ResultsIntraclass correlation coefficients for pressure pain thresholds (PPTs) via pressure algometry of the femoral, common peroneal, tibial, and sciatic nerves were 0.69, 0.84, 0.64, and 0.9 for intrarater reliability, respectively, and 0.82, 0.7, 0.56, and 0.75 for interrater reliability. κ Values for manual palpation were 0.59, 0.55, 0.42, and 0.60 for intrarater reliability and 0.30, 0.49, 0.37, and 0.60 for interrater reliability. Males demonstrated significantly higher PPTs than females for the femoral, sciatic, and tibial nerves, and differences in PPTs were present between right and left sides. ConclusionNerve palpation of the femoral, common peroneal, and sciatic nerves using pressure algometry demonstrated good to excellent reliability, whereas the tibial nerve PPTs showed moderate to good reliability. Manual palpation measurements demonstrated fair to moderate reliability.

Reliability Measures of Subcutaneous Pressure Pain Threshold Measurements: A Proposed Method of Assessing Painful Musculoskeletal Disorders

Background: Pressure algometry is a widely used method aiming to investigate deep tissue mechanical pain threshold in painful musculoskeletal disorders. Considering from the literature the input of skin and subcutaneous tissue in the determination of pressure pain threshold, and the distinctive role in clinical setting of the subcutaneous pressure threshold measurement(sPPT), it becomes necessary to investigate the reliability of the sPPT measurements. This study examines the short and longer-term intra-examiner reliability of sPPT measurements. Methods: Thirty subjects were examined at 3 pre-determined time intervals, in various parts of the body, by the same examiner in the same clinical setting. Short (between days) and longer-term (after a week) test-retest reliability was investigated. A number of statistical procedures was computed: ICC, ANOVA, standard error of measurement (SEM), smallest detectable difference (SDD) and confirmatory scatterplots. Results: The ICC statistic reached good to excellent levels for both types of reliability (0.70 – 0.97). ANOVA produced non-significant differences at all measurements. SEM gave a satisfactory overall mean value of 6.07 kPa (short-term) for all measuring sites (range: 3.2-10.1) and similarly for the longer-term reliability (Mean=6.2, range:3.1-11.2). SDD were satisfactory in the majority of the measurements [short: Mean=11.76, range: 5.9-20, longer: Mean=12.0, range: 6.5-22] but relatively high in some measuring sites, nevertheless fully acceptable and safely within the pressure algometry limits as defined in the literature. Conclusions: Subcutaneous pressure threshold measurement is a reliable to reproduce with stable results procedure, either for short or longer periods of time (from 1 to 7 days), across the whole body (upper – lower body),by the same examiner. Its fluctuation in absolute values is within the literature limits of deep pressure algometry.

Methodology and demographics of a single blinded, randomized controlled trial of chiropractic compared to physical therapy for balance impairments in community dwelling geriatric patients with or without low back pain

Postural control problems effect between 28% and 35% of individuals over the age 65 and increases with age. Musculoskeletal pain in the elderly impacts 20% to 49% of people between the ages of 65 and 75, is a leading falls risk factor, and a robust predictor of morbidity. Polypharmacy in the management of chronic pain is common in the geriatric population. Conservative treatment options for balance and back pain are underrepresented in scientific literature. The methods and demographics for a prospective, randomized controlled single blinded clinical trial are described. This study evaluated the use of either chiropractic care or physical therapy as a treatment for patients with balance problems and with low back pain (68.5%) or without low back pain (31.5%) in the geriatric population. One hundred and sixty eight consecutively enrolled community dwelling adults between 60 and 85 years old (72.8 +/- 6.8) were randomly assigned to 6 weeks of either chiropractic care or physical therapy (12 - 18 visits). Testing occurred prior to randomization, after 6 weeks of treatment, and again 6 weeks later. Functional and self-report outcome measures for balance included the Berg Balance Scale, Performance Oriented Mobility Assessment, Timed Up and Go Test, and NeuroCom balance tests. Pain was assessed with the Visual Analog Scale, 21-Point Box Scale, and pressure algometry. Quality of life healthcare questionnaires included the Oswestry, the SF-36, and the Falls Efficacy Scale for confidence in performing everyday activities. Data analysis for this intent-to-treat design was a mixed-model analysis of variance (ANOVA) (p < 0.05) and Bonferroni correction (p < 0.017 and p < 0.025). This study was set in a university biomedical and healthcare research facility and university ethics committee approval was obtained and written informed consent was given by all study participants. The methodology of this multimodal treatment protocol for balance disorders and low back pain in the geriatric population and patient demographics are described in this paper. Additional research in this area is needed for this growing at risk population. NCT02031562.

Temporal summation of pain and ultrasound Doppler activity as predictors of treatment response in patients with rheumatoid arthritis: protocol for the Frederiksberg hospitals Rheumatoid Arthritis, pain assessment and Medical Evaluation (FRAME-cohort) study

IntroductionChronic pain is common in rheumatoid arthritis (RA) and may still persist despite regression of objective signs of inflammation. This has led researchers to hypothesise that central pain sensitisation may...

The Effect of Pulsed Electromagnetic Fields on Back Pain in Polo Ponies Evaluated by Pressure Algometry and Flexion Testing—A Randomized, Double-blind, Placebo-controlled Trial

This study assessed the therapeutic effect of pulsed electromagnetic fields (PEMF) on the backs of Polo ponies by measuring mechanical nociceptive thresholds (MNTs) and induced back movement. Twenty Polo ponies in regular training and competition were assigned to two groups. A double-blind, placebo-controlled, crossover field study with PEMF was performed, consisting of two 10-day therapy periods. At the beginning and end of each therapy period, the MNTs from 25 sites of the horses backs were assessed by pressure algometry (PA), and induced back movement was evaluated by flexion testing. Baseline MNTs were generally low, with means between 6.4 and 10.0 kg/cm2. Significant changes in MNTs occurred nearly equally after both the PEMF and the placebo control treatments (at 5 of 25 or 6 of 25 sites, respectively) and without any regular pattern. Changes were evident, predominantly as decreased MNTs within and between treatment periods. Flexion testing revealed stiffness or avoidance in 19 of 20 horses. Results of the flexion testing showed an increased number of physiologic reactions at the end of both treatment periods compared with baseline values. The effect of PEMF on back pain and range of induced back movement could not be proven in this study. Although pretherapy values indicated the horses might have experienced back pain, all horses were still actively used in sport, and back pain might not have been severe enough to allow a significant effect to be demonstrated.

The Associations between Pain Sensitivity and Knee Muscle Strength in Healthy Volunteers: A Cross-Sectional Study

Objectives. To investigate associations between muscle strength and pain sensitivity among healthy volunteers and associations between different pain sensitivity measures. Methods. Twenty-eight healthy volunteers (21 females) participated. Pressure pain thresholds (PPTs) were obtained from 1) computer-controlled pressure algometry on the vastus lateralis and deltoid muscles and on the infrapatellar fat pad and 2) computerized cuff pressure algometry applied on the lower leg. Deep-tissue pain sensitivity (intensity and duration) was assessed by hypertonic saline injections into the vastus lateralis, deltoid, and infrapatellar fat pad. Quadriceps and hamstring muscle strength was assessed isometrically at 60-degree knee flexion using a dynamometer. Associations between pain sensitivity and muscle strength were investigated using multiple regressions including age, gender, and body mass index as covariates. Results. Knee extension strength was associated with computer-controlled PPT on the vastus lateralis muscle. Computer-controlled PPTs were significantly correlated between sites (r > 0.72) and with cuff PPT (r > 0.4). Saline induced pain intensity and duration were correlated between sites (r > 0.39) and with all PPTs (r < −0.41). Conclusions. Pressure pain thresholds at the vastus lateralis are positively associated with knee extensor muscle strength. Different pain sensitivity assessment methods are generally correlated. The cuff PPT and evoked infrapatellar pain seem to reflect the general pain sensitivity. This trial is registered with ClinicalTrials.gov: NCT01351558.

150. Somatic pain sensitivity during experimentally-induced inflammation in humans

Background: Enhanced pain sensitivity is a component of sickness behavior in experimental animals. However, data on the effects of systemic immune activation on pain processing in humans are rare thus far. Therefore, the goal of this ongoing study is to analyze time- and dose-dependent effects of experimentally-induced systemic immune activation on somatic pain responses in healthy male volunteers. Methods: Employing a randomized, placebo-controlled between-group design, healthy male subjects receive an i.v. injection of either lipopolysaccharide (LPS groups; 0.4 ng/kg or 0.8 ng/kg) or saline (control group). Pain thresholds are analyzed by using pressure algometry, pinprick stimulation and ice water test and are evaluated with visual analogue scales before (baseline) and 1, 3 and 6 h post-injection. Blood samples are taken at baseline, and 1, 2, 3, 4, and 6 h after injection to assess plasma levels of proinflammatory cytokines. Results: LPS injection resulted in a systemic, transient inflammatory response, reflected by significant increases in TNF-alpha, interleukin-6 plasma levels, and body temperature (all p

The association between pre-operative pain sensitisation and chronic pain after knee replacement: an exploratory study

Chronic pain after total knee replacement (TKR) is a prevalent condition, affecting about 20% of patients. The aim of this study was to explore the relationship between pre-operative pain thresholds and chronic pain after TKR. Patients listed for a TKR because of osteoarthritis participated in a Quantitative Sensory Testing (QST) session prior to surgery. Pressure pain thresholds (PPTs) and hot pain thresholds were assessed at the osteoarthritic knee and the forearm. Patients were followed-up at 1-year after TKR, and the severity of pain in the replaced knee was assessed using the WOMAC Pain score. Pre-operative median QST thresholds were compared to thresholds from a normative database collected from 50 people with no knee pain. The relationship between pre-operative pain thresholds and pain severity post TKR were tested using correlations. Fifty-one patients participated in a pre-operative QST session and completed a 1-year WOMAC Pain score. Pre-operatively, patients demonstrated evidence of localised (knee) and widespread (forearm) pain sensitisation in response to pressure stimuli compared to healthy participants. Pre-operative PPTs at the forearm were found to be significantly correlated with 1-year WOMAC Pain scores (r=0.37, P=0.008). This study provides preliminary evidence that pre-operative widespread pain sensitisation, measured using pressure algometry, may be associated with chronic pain after TKR. Further research is needed to explore the predictive value of an assessment of pre-operative widespread pain sensitisation in identifying who is likely to develop chronic pain after TKR.

Increased pain sensitivity but normal function of exercise induced analgesia in hip and knee osteoarthritis – treatment effects of neuromuscular exercise and total joint replacement

To assess exercise induced analgesia (EIA) and pain sensitivity in hip and knee osteoarthritis (OA) and to study the effects of neuromuscular exercise and surgery on these parameters. The dataset consisted of knee (n=66) and hip (n=47) OA patients assigned for total joint replacement at Lund University Hospital undergoing pre-operative neuromuscular exercise and 43 matched controls. Sensitivity to pressure pain was assessed by pressure algometry at 10 sites. Subjects were then instructed to perform a standardized static knee extension. Pressure pain thresholds (PPTs) were assessed at the contracting quadriceps muscle (Q) and at the resting deltoid muscle (D) before and during contraction. The relative increase in PPTs during contraction was taken as a measure of localized (Q) or generalized (D) EIA. Patients were assessed at baseline, following on average 12 weeks of neuromuscular exercise and 3 months following surgery. We found a normal function of EIA in OA patients at baseline. Previous studies have reported beneficial effects of physical exercise on pain modulation in healthy subjects. However, no treatment effects on EIA were seen in OA patients despite the increase in muscle strength following neuromuscular exercise and reduced pain following surgery. Compared to controls, OA patients had increased pain sensitivity and no beneficial effects on pain sensitivity were seen following treatment. To our knowledge, this is the first study of EIA in OA patients. Despite increased pain sensitivity, OA patients had a normal function of EIA.

Comfrey root extract in combination with methylnicotinate in the treatment of acute upper or lower back pain: Results of a double-blind, placebo-controlled, multicenter, three-arm RCT

Several RCTs have confirmed the efficacy of comfrey root extract (Symphytum officinale L.) (CRE) in painful muscle and joint complaints. The topical pharmacotherapeutic approach has also included hyperaemising drugs to relax the contracted muscle area. Thus, the extract has also been used in combination with methylnicotinate (MN). The objective was to show the superiority of a CRE plus MN cream (Kytta-Balsam® f) to MN and placebo cream in patients with acute upper or low back pain. In this RCT 379 patients were assigned to three groups (combination of 35% CRE plus 1.2% MN, n = 163; MN, n = 164; placebo, n = 52) and applied a 12 cm layer of cream 3 times daily for 5 days. The trial included four visits. The primary efficacy variable was the AUC (area under the curve) of the VAS (Visual Analogue Scale) on active standardised movement values at visits 1 to 4. Patients performed standardised, muscle group specific tests. Secondary measures included back pain at rest, pressure algometry, consumption of analgesic medication, functional impairment measured with Oswestry Disability Index, and global assessment of response. The AUC of the VAS on active standardised movement was markedly smaller in the combination treatment group than in the MN and the placebo group (ANOVA: p < 0.0001). The pairwise comparisons of the mean AUCs of VAS sums showed values 27% lower in favour of the combination compared to MN, and values 50% lower in favour of the combination compared to placebo. MN alone reached a reduction in this variable of 31% compared to placebo. All pairwise comparisons were statistically significant (t-test: p < 0.0001). The results were consistent across the primary and all secondary variables. Patients treated with the combination had significant superior reductions in pain scores and were more satisfied with the treatment effect. The combination demonstrated superiority to the two other treatment arms, while methyl nicotinate displayed a considerable effect as well.

Pressure algometry and thermal sensitivity for assessing pain sensitivity and effects of flunixin meglumine and sodium salicylate in a transient lameness model in sows

Sow lameness can result in decreased animal health and productivity, and is a significant animal welfare concern. Swine producers and veterinarians lack objective assessment tools to detect lameness. Objectives of this study were to evaluate pressure algometry (PA) and thermal sensitivity (TS) as objective assessment tools for changes in pain sensitivity associated with lameness and to assess analgesic drugs for mitigating lameness pain. Twelve mixed parity crossbred sows were anesthetized and injected with Amphotericin B in the distal interdigital space of both claws of one hind leg to induce transient lameness. Sows were randomly assigned to one of three analgesic treatment groups: (1) Sodium Salicylate (SS; 35mg/kg per os q.12h+0.04ml/kg IM q.24h sterile saline), (2) Flunixin meglumine (FM; 2.2mg/kg IM q.24h), or (3) Control (C; 0.04ml/kg IM q.24h sterile saline). All sows received each treatment over three trials with two-wk wash-out periods between trials. Forty-eight h post-induction, analgesic treatments were administered daily for four consecutive d. Pain sensitivity was assessed with PA and TS on each hind leg on d−1, d+1 and d+6 relative to induction (d0). Proc Glimmix of SAS 9.2 was used to analyze the difference between sound (S) and lame (L) legs on each trial day, with a simple effect comparison used to analyze effect of analgesia treatment on d+6. As predicted, S and L legs did not differ on d−1 (P=0.56) and less pressure was tolerated on L legs on d+1 (P<0.001) (Raw Means in kilograms of force: d−1 L 7.2±0.2; d−1 S 7.4±0.2; d+1 L 2.1±0.2; d+1 S 7.7±0.2kgf). A simple effect comparison of d+6 revealed no differences between FM and C (p=0.90), FM and SS (p=0.17), or SS and C (p=0.07). The TS latency of S versus L legs differed on all trial days (d−1 p=0.02, d+1 p<0.0001, d+6 p<0.01) over all trials. (TS Raw means (s): d−1 L 7.3±0.6; d−1 S 9.1±0.6; d+1 L 3.3±0.2; d+1 S 6.8±0.6; d+6 L 6.0±0.6; d+6 S 8.4±0.7s), including lame and sound days. In conclusion, these results support PA as an objective non-invasive method for measuring pain sensitivity in sows induced with transient lameness. Sodium salicylate or flunixin meglumine did not reduced pain sensitivity as measured by PA from d+1 to d+6 in this model of induced transient lameness.

Repeated intramuscular injections of nerve growth factor induced progressive muscle hyperalgesia, facilitated temporal summation, and expanded pain areas

Intramuscular injection of nerve growth factor (NGF) is known to induce deep-tissue mechanical hyperalgesia. In this study it was hypothesised that daily intramuscular injections of NGF produce a progressive manifestation of soreness, mechanical hyperalgesia, and temporal summation of pain. In a double-blind placebo-controlled design, 12 healthy subjects were injected on 3days with NGF into the tibialis anterior muscle and with isotonic saline on the contralateral side. Assessments were performed before and after the injections on days 0, 1, and 2, and repeated on days 3, 6, and 10. The self-perceived muscle soreness was assessed on a Likert scale. Computer-controlled pressure algometry was used to assess the pressure pain thresholds (PPTs). Temporal summation of pain after repeated pressure stimulations was assessed by computer-controlled pressure algometry. The pain distribution following painful pressure stimulation was also recorded. Compared with baseline and isotonic saline, the NGF injections caused (P<0.05): (1) progressively increasing soreness scores from 3hours after the first injection until day 2, after which it remained increased; (2) decreased PPTs at days 1 to 3; (3) facilitated temporal summation of pressure pain at days 1 to 10; and (4) enlarged pressure-induced pain area after the injection on day 1 to day 6. The daily injections of NGF produced a progressive manifestation of muscle soreness, mechanical hyperalgesia, temporal summation of pressure pain, and pressure-induced pain distribution. These data illustrate that the prolonged NGF application affects peripheral and central mechanisms and may reflect process in musculoskeletal pain conditions.

Medial tibial pain pressure threshold algometry in runners

Pressure algometry (PA) may provide an objective and standardised tool in assessing palpation pain over the tibia. The purpose of this study was to analyse the intra-rater repeatability of PA and to determine whether tibial tenderness in healthy runners differ from runners with medial tibial stress syndrome (MTSS). Pressure algometry was performed on 20 asymptomatic runners (40 legs) and 9 MTSS patients (14 symptomatic legs) at standardised locations along the medial border of the tibia. Intra-rater reliability was assessed in 10 randomly selected asymptomatic runners through repeated measurements 2 weeks later. Intra-rater reliability was moderate to excellent (ICC 0.53-0.90) in asymptomatic runners. Pain pressure threshold (PPT) was significantly reduced at 2/9-5/9 of the distance from the medial malleolus to the medial tibial condyle (p = 0.002-0.022). There was evidence of a statistically significant association between both height and weight, and PPT from the 3/9 (r = 0.416, p = 0.008) to 7/9 (r = 0.334, p = 0.035) and 3/9 (r = 0.448, p = 0.004) to 6/9 (r = 0.337, p = 0.034) area, respectively. In both MTSS patients and healthy runners, there was evidence of lower PPT in females compared to males (p = 0.0001-0.049) and a negative association between age and PPT (p = 0.001-0.033). MTSS patients had significantly lower PPT at the 3/9 site (p = 0.048) compared to asymptomatic runners. Pain pressure threshold algometry can be incorporated into MTSS clinical assessment to objectively assess pain and monitor progress. The presence of reduced medial tibial PPT in asymptomatic runners suggests that clinicians may not need to await resolution of medial tibia tenderness before allowing return to sport in MTSS patients.

SAT0068 The Ts-Index as Sign Of Central Sensitization in Women with Active Rheumatoid Arthritis: A Comparative Cross Sectional Study

BackgroundDespite better disease control, RA patients still rate pain as a major burden. That pain in some cases persists without signs of inflammation of the joints may indicate, that central...

The prevalence of widespread central hypersensitivity in chronic pain patients

Chronic pain is associated with generalized hypersensitivity and impaired endogenous pain modulation (conditioned pain modulation; CPM). Despite extensive research, their prevalence in chronic pain patients is unknown. This study investigated the prevalence and potential determinants of widespread central hypersensitivity and described the distribution of CPM in chronic pain patients. We examined 464 consecutive chronic pain patients for generalized hypersensitivity and CPM using pressure algometry at the second toe and cold pressor test. Potential determinants of generalized central hypersensitivity were studied using uni- and multivariate regression analyses. Prevalence of generalized central hypersensitivity was calculated for the 5th, 10th and 25th percentile of normative values for pressure algometry obtained by a previous large study on healthy volunteers. CPM was addressed on a descriptive basis, since normative values are not available. Depending on the percentile of normative values considered, generalized central hypersensitivity affected 17.5-35.3% of patients. 23.7% of patients showed no increase in pressure pain threshold after cold pressor test. Generalized central hypersensitivity was more frequent and CPM less effective in women than in men. Unclearly classifiable pain syndromes showed higher frequencies of generalized central hypersensitivity than other pain syndromes. Although prevalent in chronic pain, generalized central hypersensitivity is not present in every patient. An individual assessment is therefore required in order to detect altered pain processing. The broad basic knowledge about central hypersensitivity now needs to be translated into concrete clinical consequences, so that patients can be offered an individually tailored mechanism-based treatment.

The repeatability of pressure algometry in asymptomatic individuals over consecutive days

BackgroundTo determine if electronic pressure algometry is a statistically stable measure of spinal pressure pain threshold (PPT) in asymptomatic individuals, in particular, to determine if repeated measurements at the same site changes the PPT, and to determine if repeatability differs in each of the spinal regions tested. DesignRepeated measures design. SettingUniversity teaching clinic. ParticipantsThirty-three asymptomatic participants. InterventionsThe PPT of three spinal segments (C6, T6 and L4) was measured three times in consecutive measures (10 s apart), then repeated one day and two days post-initial measurement. Measurements were taken using an electronic pressure algometer. Main outcome measuresPPT, intra-class correlation coefficient and test of significant equality. ResultsResults demonstrated that the PPT measurement is statistically stable both between days (p < 0.001) and within day (p < 0.001). The intra-class correlation coefficient (ICC) values between the mean scores of daily trials demonstrated excellent concordance for each spinal segment (ICC = 0.860–0.953), with the exception of the correlation between day 1 and day 3 at T6, demonstrating good concordance (ICC = 0.676). All trial-to-trial correlations demonstrated excellent concordance both within trials of the same day (ICC = 0.833–0.988) and subsequent days (ICC = 0.823–0.940). ConclusionElectronic pressure algometry is a repeatable and statistically stable measure of the spinal PPT, both between days and within-day. The results provide evidence that the use of this device may be of value as an outcome measure for primary spinal complaints such as low back or thoracic spine pain.