Differences In Pain Tolerance Research Articles

Virtual Reality Facilitated Exercise Increases Sympathetic Activity and Reduces Pain Perception: A Randomized Crossover Study.

Both virtual reality (VR) and exercise reduce pain while avoiding the risks of traditional pharmacotherapy. The aim of this study was to assess how VR-facilitated exercise modulates sympathetic activity and pain perception. Healthy adult volunteers were randomized by hand dominance and then subjected to a standardized cold pressor test while experiencing a VR application. After a 5-minute washout, participants were crossed-over and repeated the test on their other hand while undergoing a VR-facilitated exercise application. Sympathetic activation, pain sensation, and pain tolerance data were collected identically during both conditions. 110 participants were analyzed. Sympathetic activity increased in both conditions but was higher in the VR-facilitated exercise condition (p < 0.0001). Pain sensation scores were initially higher with VR-facilitated exercise but dropped below the VR-only condition by the end of the intervention (p = 0.0175). There were no differences in pain tolerance between conditions (p = 0.18). The decrease in pain perception with VR-facilitated exercise condition compared to VR alone indicates VR-facilitated exercise can be a useful tool for managing pain. Though this effect did not translate into higher pain tolerance, VR-facilitated exercise may be a useful intervention in the setting of physical therapy or for patients with chronic pain.

Interactive and passive mixed reality distraction: effects on cold pressor pain in adults.

While interactive distractors are predicted to be more effective in reducing acute pain than passive distractors, the underlying mechanisms remain poorly understood. Previous work using Virtual-Reality (VR) has suggested that interactive distraction may be enhanced by increasing the person's sense of immersion. Despite the possible utility of immersive VR in reducing pain, some people report being disoriented and motion sick, and it doesn't allow for interactions with environment (e.g., following instructions from medical staff). Here, we explore the role of the immersion in the effectiveness of interactive distraction by employing an alternative technology, a Mixed-Reality (MR) headset that limits disorientation by projecting virtual objects into the real world. Healthy volunteers (18-35 years) participated in two experiments employing either a between (N = 84) or a within-subject (N = 42) design to compare Interactive and Passive distraction tasks presented via MR or a standard computer display. For both experiments, a cold-pressor task was used to elicit pain, with pain tolerance and pain perception being recorded. Analysis revealed that whilst interactive distraction was more effective in reducing pain perception and increasing pain tolerance than passive distraction, the interpretation of results was sensitive to experimental design. Comparison of devices did not reveal significant differences in pain tolerance or pain intensity, while pain unpleasantness was significantly reduced during the MR task using a within-subject design. Our findings add to existing VR studies reporting little additional analgesic benefit of new, immersive technologies compared to traditional computers, but underscores the important impact the choice of experimental design can have on the interpretation of results.

Remote ischaemic preconditioning increase tolerance to experimentally induced cold pain

ABSTRACT Ischaemic preconditioning (IPC) applied locally and remotely has been shown to reduce pain which may underpin its ergogenic effect on exercise performance, however, it is unclear how many IPC cycles are needed to induce hypoalgesia. Therefore the purpose of this study was to examine the number of cycles of IPC on experimental pain perception. Sixteen healthy participants underwent four, randomised, experimental sessions where they either underwent a sham protocol (1 × 5 min at 20 mmHg), and 1, 2 or 3 cycles × 5 min of remote IPC at 105% of limb occlusion pressure. Ten minutes post-intervention, participants underwent a cold-pressor test where pain threshold, pain tolerance and pain intensity were examined and compared between conditions with a one-way repeated measure analysis of variance. Pain threshold was not different between conditions (P = 0.065); but pain tolerance was increased by ∼30% in the 1 × 5 condition, 2 × 5 condition, and 3 × 5 condition compared to the sham condition. No differences in pain tolerance were seen between the different numbers of cycles (all P > 0.05). There was also no difference in the perception of pain 30 s into the cold pressor test (P = 0.279). Remote IPC appears to significantly improve tolerance to pain which may have significant implications for endurance performance and exercise rehabilitation, but this warrants further investigation.

Virtual reality facilitated exercise improves pain perception: A crossover study

Study objectiveBoth virtual reality (VR) and exercise are recognized for their analgesic and anxiolytic properties. The purpose of this study is to evaluate the ability of VR-facilitated exercise to modulate pain. DesignWithin-subject cross-over clinical trial. SettingThe Stanford Chariot Program conducted this study at Lucile Packard Children's Hospital Stanford (LCPHS). PatientsHealthy participants meeting inclusion criteria were recruited by volunteer solicitation from LCPHS. InterventionsParticipants were randomized by hand dominance and subjected to a standardized cold pressor test with no VR or exercise. After a 5-min wash-out period, participants repeated the test on their other hand while experiencing a VR-facilitated exercise condition. Pain sensitivity, pain tolerance, and sympathetic activation data were collected during both conditions. MeasurementsPain sensitivity was scored 0–10 and collected every 30 s. Pain tolerance was recorded as the duration a participant could endure the painful stimuli. Sympathetic activation was measured by skin conductance response density (SCRD) and recorded in 30 s epochs by a biosensor. In all analyses, data were nested by participant. Main resultsForty-one participants completed both interventions. Pain sensitivity was reduced in the VR-facilitated exercise condition (p < 0.0001). There was no difference in pain tolerance between conditions. While both conditions resulted in an increase in sympathetic activity, SCRD was higher at all time points in the VR-facilitated exercise condition. ConclusionsThe reduction in pain sensitivity indicates VR-facilitated exercise results in improved pain perception. VR-facilitated exercise may be especially useful for patients with chronic pain or other conditions requiring physical therapy, where pain may be exacerbated by exercise.

Myocardial Infarction Signs and Symptoms: Females vs. Males.

Cardiovascular disease is the number one killer of females in the United States today, and myocardial infarction (MI) plays a role in many of these deaths. Females also present with more "atypical" symptoms than males and appear to have differences in pathophysiology underlying their MIs. Despite both differences in symptomology and pathophysiology being present in females versus males, a possible link between the two has not been studied extensively. In this systematic review, we analyzed studies examining differences in symptoms and pathophysiology of MI in females and males and evaluated possible links between the two. A search was performed for sex differences in MI in the databases PubMed, CINAHL (Cumulative Index to Nursing and Allied Health Literature) Complete, Biomedical Reference Collection: Comprehensive, Jisc Library Hub Discover, and Web of Science. Seventy-four articles were ultimately included in this systematic review. Typical symptoms for both ST-elevation myocardial infarction (STEMI) and non-STEMI (NSTEMI) such as chest, arm, or jaw pain were more common in both sexes, but females presented on average with more atypical symptoms such as nausea, vomiting, and shortness of breath. Females with MI also presented with more prodromal symptoms such as fatigue in days leading up to MI, had longer delays in presentation to the hospital after symptom onset, and were older with more comorbidities than males. Males on the other hand were more likely to have a silent or unrecognized MI, which concurs with their overall higher rate of MI. As they age, females have a decrease in antioxidative metabolites and worsened cardiac autonomic function than male. In addition, at all ages, females have less atherosclerotic burden than mles, have higher rates of MI not related to plaque rupture or erosion, and have increased microvasculature resistance when they have an MI. It has been proposed that this physiological difference is etiologic for the male-female difference in symptoms, but this has not been studied directly and is a promising area of future research. It is also possible that differences in pain tolerance between males and females may play a role in differing symptom recognition, but this has only been studied one time where females with higher pain thresholds were more likely to have unrecognized MI. Again, this is a promising area for future study for the early detection of MI. Finally, differences in symptoms for patients with different atherosclerotic burden and for patients with MI due to a cause other than plaque rupture or erosion has not been studied and are both promising avenues to improve detection and patient care in the future.

Can Sensory- and Attachment-Informed Approaches Modify the Perception of Pain? An Experimental Study.

Accumulating evidence linking pain with both attachment and sensory processing variables introduces the possibility that attachment- and sensory-informed strategies may modify pain experiences. The aim of this study was to investigate this proposition using an experimentally induced pain procedure. Pain perceptions of individuals using either a sensory-informed (weighted modality) or an attachment-informed (secure base priming) coping strategy were compared with those of individuals using no designated coping strategy. An independent measures experimental study design was used with a convenience sample of 272 pain-free adults. Experimental participants (n = 156) were randomly allocated to either an attachment (n = 75) or a sensory (n = 81) intervention group. Data from these participants were compared to those of 116 participants involved in an earlier cold pressor study in which no coping strategy was used. All participants completed the same sensory, attachment, and distress questionnaires and participated in the same cold pressor pain test. ANCOVAs revealed that participants in the sensory- and attachment-informed intervention groups reported significantly higher pain thresholds than the control group. Participants allocated to the sensory group also reported higher pain intensity scores than the control group. There were no significant differences in pain tolerance between the three groups after controlling for covariates. While further research is required, findings encourage further consideration of sensory- and attachment-informed strategies for people anticipating a painful experience.

Pain Tolerance: The Influence of Cold or Heat Therapy

ObjectivesResources of heat or cold therapies have been widely used for their low cost, analgesic action and for assisting the rehabilitation of acute or chronic injuries. The objective of this study was to search for associations between skin surface temperature and pressure pain tolerance thresholds (PPTs) of healthy individuals undergoing cryotherapy and thermotherapy. MethodsThis is an experimental clinical trial with 22 healthy university students aged between 18 and 35 years. Volunteers underwent thermography and algometry assessments at 6 points in both knees before, immediately after, and 20 minutes after the application of frozen (cryotherapy) or heated (thermotherapy) gel bags in the right knee for 20 minutes. Data were analyzed by 1-way analysis of variance, Student's t test, and Pearson or Spearman correlation tests. ResultsThere was a significant change in skin surface temperature after cryotherapy and thermotherapy, which was maintained after 20 minutes of withdrawal (P < .001). After the intervention, no significant differences were observed regarding the PPT compared to the baseline measurements, nor between the experimental and control knees. ConclusionCryotherapy and thermotherapy produced significant changes in the temperature of the evaluated points after their application. Despite this, no differences in pain tolerance were observed, and there was little association between skin surface temperature and PPT in the knees of healthy women after application of the resources.

Associations Between Skin Surface Temperature and Pressure Pain Tolerance Thresholds of Asymptomatic Individuals Exposed to Cryotherapy and Thermotherapy

ObjectiveThe purpose of this study was to evaluate associations between skin surface temperature and pressure pain tolerance thresholds (PPTs) of asymptomatic individuals exposed to cryotherapy and thermotherapy. MethodsTwenty-two asymptomatic female university students aged between 18 and 35 years underwent thermography and algometry assessments at 6 points in both knees before, immediately after, and 20 minutes after the application of frozen (cryotherapy) or heated (thermotherapy) gel bags in the right knee for 20 minutes. Data were analyzed by 1-way analysis of variance, Student t test, and Pearson or Spearman correlation tests. ResultsThere was a significant change in skin surface temperature after cryotherapy and thermotherapy, which was maintained after 20 minutes of withdrawal (P < .001). After the intervention, no significant differences were observed regarding PPT compared with the baseline measurements, nor between the experimental and control knees. ConclusionCryotherapy and thermotherapy produced significant changes in the temperature of the evaluated points after their application. No differences in pain tolerance were observed in these asymptomatic participants. There was little association between skin surface temperature and PPT in the knees of healthy women after application of the resources.

Does Anthropomorphism of Dogs Affect Pain Perception in Animal-Assisted Interventions? An Exploratory Study

ABSTRACTThe purpose of this exploratory study was to determine the effects of anthropomorphism of a therapy dog on pain perception during an animal-assisted intervention. Participants were 32 college women who were randomly assigned to the anthropomorphism condition or the control condition. All participants engaged in a pretest cold pressor task to measure base-line individual differences in pain tolerance and perceptions of pain intensity and pain unpleasantness. After completing this task, participants in the anthropomorphism group engaged in a task intended to prime them to view a therapy dog anthropomorphically. Specifically, they rated photos of dogs on a series of humanlike traits (e.g., “this dog would be a good listener”). Participants in the control condition rated photos of dogs on a series of canine traits (e.g., “this dog would make a good watchdog”). After this experimental manipulation, participants engaged in a second cold pressor task in the presence of a therapy dog and the therapy dog handler. We hypothesized that participants in the anthropomorphism group would demonstrate greater pain tolerance and report lower levels of pain intensity and pain unpleasantness during the second cold pressor task than participants in the control group. Results provide partial support for these hypotheses. Participants in the anthropomorphism group reported lower posttest pain intensity than participants in the control group. In addition, they demonstrated greater posttest pain tolerance than participants in the control group—but only under conditions of medium or high pretest pain tolerance. The two groups did not differ with respect to posttest pain unpleasantness. The results of this exploratory study provide preliminary evidence that prompting individuals to view a therapy dog anthropomorphically may augment their experience of pain relief from a therapy dog visit.

(252) The Role of Self-Other Comparisons in Race Differences in Pain Tolerance

Research has found race differences in pain sensitivity and tolerance. Evidence suggests how people compare themselves to similar others influences interpretations of their own health and well-being. We examined participants’ perceptions of their pain sensitivity compared to their perceptions of the pain sensitivity of “typical” members of their race (self-other comparison) and how these self-other comparisons related to race differences in actual pain tolerance. Black and White undergraduates (N=132; 48.5% Black) completed the Race/Ethnicity Expectations of Pain Questionnaire and a cold pressor task. First, we examined participants’ beliefs related to race differences in pain using a paired samples t-test to understand the perceived pain sensitivity of the comparison groups. Then, we examined how participants’ self-other comparison ratings for pain moderated the relationship between race and actual pain tolerance using a robust multiple-group moderation analysis. Results indicated participants rated the “typical” Black person as less pain sensitive than the “typical” White person (t(131)=-6.83, p

Relationship between Serum Methadone Concentration and Cold Pressor Pain Sensitivity in Patients Undergoing Methadone Maintenance Therapy.

Hyperalgesia is a common clinical phenomenon among opioid dependent patients on methadone maintenance therapy (MMT) and it may be associated with undertreated pain and/or therapeutic failure. This study aimed to investigate association between serum methadone concentration (SMC) and cold pressor pain responses. Cold pressor pain responses in 147 opioid dependent patients on MMT were assessed using cold pressor test (CPT) at 0 h and at 2, 4, 8, 12, and 24 h after the dose intake. Blood samples were collected at 24 h after the dose. Serum methadone concentrations were measured using the Methadone ELISA kit and classified into two categories: < 400 ng/mL and ≥ 400 ng/mL. Eighty-eight patients (59.9%) had trough concentrations of < 400 ng/mL and 40.1% had trough concentrations of ≥ 400 ng/mL. There were significant effects of SMC on the cold pressor pain threshold (p = 0.019). Patients with concentrations < 400 ng/mL had significantly higher (almost 60% higher) cold pressor pain threshold (adjusted mean (95% CI) = 30.15 (24.29, 36.01) s) compared to those with concentrations of ≥ 400 ng/mL (18.93 (11.77, 26.08) seconds). There was also a 20% difference in pain tolerance, and 6% difference in cold pressor pain intensity score, neither of which were significant statistically (p > 0.05). Our results suggest an association of trough methadone concentration with the cold pressor pain threshold among opioid dependent patients on MMT. It would be useful to study the mechanisms underlying this association to help managing pain in such a population.

The effect of acute intermittent exercise on pain threshold and tolerance in middle-aged tennis players

Aim: The purpose of this study is to examine the alterations in pain threshold and tolerance of middle-aged persons those who regularly play tennis at rest and following acute voluntary exercise. Methods: Fifty-nine recreationally-active persons aged 30-60 years participated in this study. Women and men separately were divided into 10-years groups, with 30-39, 40-49 and 50-59 years of age. Pressure pain threshold (PPT) and pain tolerance (PPT) measurements were recorded at rest and immediately following an acute exercise. PPT and PPTO values were measured from the biceps muscle of dominant arm by using a digital algometer. Singles tennis match was used as an acute voluntary exercise session, the duration of each tennis match (min) and rate of perceived exertion (RPE) were recorded. Results: No statistical differences were found in exercise duration or RPE scores among groups. RPE scores showed that tennis match played by participants was corresponded a strenuous exercise session. In all age groups, no statistical differences were found in baseline PPT or PPTO results in women or men. PPT and PPTO values were increased following exercise both in women and men. Although post-exercise PPT results were similar among age groups of women and men, PPTO values of men were found to be higher in all age groups of men in comparison with the same age groups of women. Conclusion: In conclusion, the present study revealed that one bout of voluntary exercise session resulted in gender-dependent differences in pain tolerance in middle-aged participants, and those middle-aged men were tolerated of pain at higher pressure levels following exercise in comparison with women at the same age.

Brief relaxation training is not sufficient to alter tolerance to experimental pain in novices.

Relaxation techniques, such as deep breathing and muscle relaxation, are aspects common to most forms of mindfulness training. There is now an abundance of research demonstrating that mindfulness training has beneficial effects across a wide range of clinical conditions, making it an important tool for clinical intervention. One area of extensive research is on the beneficial effects of mindfulness on experiences of pain. However, the mechanisms of these effects are still not well understood. One hypothesis is that the relaxation components of mindfulness training, through alterations in breathing and muscle tension, leads to changes in parasympathetic and sympathetic nervous system functioning which influences pain circuits. The current study seeks to examine how two of the relaxation subcomponents of mindfulness training, deep breathing and muscle relaxation, influence experiences of pain in healthy individuals. Participants were randomized to either a 10 minute deep breathing, progressive muscle relaxation, or control condition after which they were exposed to a cold pain task. Throughout the experiment, measures of parasympathetic and sympathetic nervous system activity were collected to assess how deep breathing and progressive muscle relaxation alter physiological responses, and if these changes moderate any effects of these interventions on responses to pain. There were no differences in participants’ pain tolerances or self-reported pain ratings during the cold pain task or in participants’ physiological responses to the task. Additionally, individual differences in physiological functioning were not related to differences in pain tolerance or pain ratings. Overall this study suggests that the mechanisms through which mindfulness exerts its effects on pain are more complex than merely through physiological changes brought about by altering breathing or muscle tension. This indicates a need for more research examining the specific subcomponents of mindfulness, and how these subcomponents might be acting, to better understand their utility as a clinical treatment.

Predictors of Cold and Pressure Pain Tolerance in Healthy South African Adults.

Studies on relationships between sex, ethnicity, and pain have largely emanated from the United States and Europe. We compared cold (CPT) and pressure pain tolerance (PPT) in male and female South Africans of African and European ancestry and assessed whether psychosocial factors (including pain beliefs) predicted differences in pain tolerance. We recruited 106 (62 female) students of African ancestry and 106 (55 female) of European ancestry and subjected them to a cold-pressor test and pressure algometry. Socioeconomic status (SES), pain catastrophizing, depression, anxiety, and pain beliefs were assessed as predictors of pain tolerance. CPT was lower in students of African compared with European ancestry (for both sexes), and PPT was lower in female than male students (for both ethnicities). Females were very accepting of men expressing pain and males less so. Males of African ancestry were least accepting but still tolerant. Multivariate analysis identified African ancestry, and particularly being a female of African ancestry, as strong predictors of lower CPT. Anxiety was a weak predict or of CPT. Sex was the only strong predictor of PPT on multivariate analysis (PPT females < males), and catastrophizing was a weak predictor. Female sex and African ancestry were strong predictors of acceptance of expression of pain in males. SES was a weak predictor of the Appropriate Pain Behavior Questionnaire-Malescore. Despite different cultural and social backgrounds from US and European cohorts, we saw similar patterns of sex and ethnic differences in CPT and PPT in an African cohort. Traditional psychosocial predictors of pain sensitivity predicted variation in the outcome variables but were not strong predictors.

Sensory and physiological dimensions of cold pressor pain in trichotillomania

BackgroundTrichotillomania (TTM) is characterized by hair pulling resulting in hair loss. It has long been perceived that people with TTM may have different pain thresholds or pain tolerances than healthy counterparts. This study sought to examine whether TTM was associated with reductions in sensory or physiological components of cold pressor pain. MethodAdults with TTM were examined on clinical measures including symptom severity and functioning. All participants underwent the cold pressor test. Heart rate, blood pressure, and self-reported pain were compared between TTM participants (N=19) and controls (N=14). ResultsThere were no differences in pain tolerance between TTM participants and controls. The TTM group did not show faster recovery time nor exhibit lower pain ratings. Systolic blood pressure was significantly lower in the TTM group before immersion, though differences did not exist at pain tolerance or after the recovery period. TTM participants had a lower heart rate at all time points, but this difference was statistically significant only at 90s (p=.046). ConclusionsIn this study, adults with TTM failed to exhibit analgesia to cold pressor pain as compared with healthy controls. No association appears to exist between pain and TTM symptom severity.

Racial and ethnic differences in experimental pain sensitivity: systematic review and meta-analysis.

Our objective was to describe the racial and ethnic differences in experimental pain sensitivity. Four databases (PubMed, EMBASE, the Cochrane Central Register of Controlled Trials, and PsycINFO) were searched for studies examining racial/ethnic differences in experimental pain sensitivity. Thermal-heat, cold-pressor, pressure, ischemic, mechanical cutaneous, electrical, and chemical experimental pain modalities were assessed. Risk of bias was assessed using the Agency for Healthcare Research and Quality guideline. Meta-analysis was used to calculate standardized mean differences (SMDs) by pain sensitivity measures. Studies comparing African Americans (AAs) and non-Hispanic whites (NHWs) were included for meta-analyses because of high heterogeneity in other racial/ethnic group comparisons. Statistical heterogeneity was assessed by subgroup analyses by sex, sample size, sample characteristics, and pain modalities. A total of 41 studies met the review criteria. Overall, AAs, Asians, and Hispanics had higher pain sensitivity compared with NHWs, particularly lower pain tolerance, higher pain ratings, and greater temporal summation of pain. Meta-analyses revealed that AAs had lower pain tolerance (SMD: -0.90, 95% confidence intervals [CIs]: -1.10 to -0.70) and higher pain ratings (SMD: 0.50, 95% CI: 0.30-0.69) but no significant differences in pain threshold (SMD: -0.06, 95% CI: -0.23 to 0.10) compared with NHWs. Estimates did not vary by pain modalities, nor by other demographic factors; however, SMDs were significantly different based on the sample size. Racial/ethnic differences in experimental pain sensitivity were more pronounced with suprathreshold than with threshold stimuli, which is important in clinical pain treatment. Additional studies examining mechanisms to explain such differences in pain tolerance and pain ratings are needed.

Comparison of the Physical Properties of Showers that the Satisfaction of Shower Feeling among Users in Three Asian Countries

The purpose of this study was to construct a scheme that makes it possible to compare the relationship between water usage, satisfaction, and physical properties in three countries. The physical properties of the shower were measured using physical properties testing apparatus of water-saving standard or scheme for showerheads issued in several water-saving countries and data for users satisfaction evaluation was acquired through bathing experiments. In this paper, we analyzed the result from Taiwanese and Vietnamese individuals to compare them to of Japanese subjects analyzed in the previous study. We compared the physical properties of showers assessed low in satisfaction by Taiwanese, Vietnamese and Japanese subjects. It was assumed that spray pattern tends to decrease satisfaction when the water volume ratio within 100 mm and 150 mm of a measuring device is located a 450 mm distance from the showerhead is low, and that, because all three countries showed the same value, it was imagined that there were no differences in the water volume ratio of high-satisfaction showerheads among three countries. On the other hand, the values of Spray Force-per-Hole, Temperature Drop, and Spray Angle were different among three countries. We speculated that these differences are affected respectively by ethnic differences in pain tolerance, thermoregulatory response and bathing habit.

The Effects of Acceptance of Thoughts, Mindful Awareness of Breathing, and Spontaneous Coping on an Experimentally Induced Pain Task

The current study examined the effects of acceptance of thoughts, mindful awareness of breathing, and spontaneous coping on both pain tolerance and pain threshold during a cold pressor task. Eligible participants (N = 58), 16 males and 42 females (M age = 29.31, SD = 11.21), were randomized into three groups and completed two cold pressor trials. The first cold pressor trial formed a baseline for all three groups. The acceptance of thoughts and mindfulness of breathing groups listened to recorded instructions and then completed a second administration of the cold pressor task. The spontaneous coping group completed the cold pressor task twice with instructions to select their own coping style. Multilevel linear modeling showed significant group differences in pain tolerance. The acceptance of thoughts and mindfulness of breathing conditions resulted in significantly higher pain tolerance in post hoc analysis than spontaneous coping. Results were interpreted to be consistent with Acceptance and Commitment Therapy. Further examination of the effects of ACT processes on experimentally induced pain tolerance is needed.

Fear of needles does not influence pain tolerance and sympathetic responses among patients during a therapeutic needling

Abstract Introduction Dry needling is one of the therapies employed in pain medicine to reduce pain. However, no clear understanding exists as to whether there are differences in pain tolerance levels and sympathetic responses among individuals who have a fear of needles when compared to those who do not fear needling during dry needling treatment. Aim The main aim of this study was to investigate the differences in the pain pressure threshold and sympathetic changes among individuals who fear needling and those who do not fear needling during a sham dry needling procedure over a latent trigger point on the upper trapezius. Material and methods A cross sectional study was conducted in the Physiotherapy Outpatient Clinic at the University Teaching Hospital among 27 healthy subjects (12 subjects with needle phobia and 15 subjects with no fear of needles). Pain pressure threshold, blood pressure and heart rate were measured before and after the sham needling. The differences in the study variables between and within the groups were analyzed using a 2-way ANOVA. Results The results indicated no significant differences in pain pressure threshold ( P >.05), blood pressure ( P >.05) and heart rate ( P >.05) between and within the two groups. However, the mean (±SD) value of pain pressure threshold showed an increased trend among those subjects with a fear of needles when compared to subjects who do not fear needling, −3.12 (±1.20) and 2.97 (±0.86), respectively. Conclusions Individuals who exhibit a fear of needles showed no differences in pain tolerance and sympathetic changes when compared to those who do not fear needling during dry needling treatment.

Pain tolerance in children and adolescents: Sex differences and psychosocial influences on pain threshold and endurance

Laboratory studies with children and adolescents revealed inconsistent findings regarding sex differences in pain tolerance, although lower pain tolerance is commonly reported for adult women. Besides biological mechanisms, several socio-cognitive variables are discussed which may influence pain tolerance in regard to sex differences. The purpose of the present study was to investigate the pain tolerance of children and adolescents using the cold pressor task (CPT) and to analyse influences of pain-coping and pain-related self-efficacy. About 1021 children and adolescents aged 9-17 participated in the study. Pain tolerance was defined as the length of time a participant's hand remains under water during the CPT. Two phases of pain tolerance were differentiated: the time until pain is reported (pain threshold) and the time from the threshold until the pain increases to a level resulting in the hand being withdrawn (pain endurance). Pain-coping and pain-related self-efficacy were assessed by self-report questionnaires. We revealed an obvious effect of sex on pain threshold, which increased with age, a small effect on pain tolerance and no significant effect on endurance. Independent of sex, pain endurance was influenced by pain-related self-efficacy and positive self-instruction. Our results support the assumption that female and male adolescents develop in different directions regarding their pain tolerance when reaching puberty. This seems mainly attributable to a decrease of pain threshold in girls. In contrast, boys and girls are able to endure pain to an equal extent influenced, however, by self-efficacy and coping variables.