Physical Activity Levels Predict Exercise-induced Hypoalgesia in Older Adults

Prior research indicates that older adults exhibit a deficient capacity to activate multiple pain inhibitory mechanisms, including pain inhibition after acute exercise termed exercise-induced hypoalgesia (EIH). The influence of physical activity levels and psychological processes on EIH in older adults remains unclear. PURPOSE This study examined potential psychological and physical activity predictors of the magnitude of EIH following submaximal isometric exercise in healthy older adult men and women. METHODS Fifty-two healthy older adults completed a test of EIH, the Pain Catastrophizing Scale, the Tampa Scale of Kinesiophobia, and wore an accelerometer on the hip for one week to assess physical activity levels. For the test of EIH, participants complete a 3-minute isometric handgrip at 25% of maximum voluntary contraction. Pressure pain thresholds (PPTs) and a 30-sec continuous heat pain test were completed before and immediately after the exercise. RESULTS Mixed model ANOVAs revealed that older adults demonstrated significantly decreased PPTs following isometric exercise (p=.030), and no changes on the heat pain trials from pre to post test (p>.05). A multiple regression revealed that accumulated moderate to vigorous physical activity (MVPA) per week significantly predicted the change in PPT following exercise (β=0.35, p=.012). Participants who averaged greater MVPA experienced a greater increase in PPTs after exercise. No relationships were found with EIH and the psychological variables. CONCLUSIONS Older adults did not exhibit EIH following submaximal isometric exercise. However, those who did more MVPA per week experienced a greater magnitude of pain inhibition following acute exercise

Greater functional aerobic capacity predicts more effective pain modulation in older adults

poster abstractEndogenous pain inhibitory and facilitory function deteriorates with age, potentially placing older adults at greater risk for chronic pain. Prior research shows that self-reported physical activity predicts endogenous pain inhibitory capacity and facilitation of pain on quantitative sensory tests (QST) in healthy adults. Purpose: To investigate whether functional aerobic capacity and lower extremity strength in older adults cross-sectionally predicts pain sensitivity, pain inhibition following isometric exercise, and facilitation of pain during heat pain temporal summation (TS) tests. Methods: 42 subjects (10 male, 32 female, age=67.5±5.1) completed the 6-minute walk test (6MWT), 30-second chair stand test, and several QSTs. QSTs included: 1) Pain ratings (0-100 scale) during the submersion of the hand in a cold water bath (CWB), 2) heat pain threshold tests, 3) the amount of pain reduction following submaximal isometric exercise, and 4) degree of pain facilitation during temporal summation tests conducted at 44, 46, and 48°C. Responses on the QSTs were analyzed using hierarchical linear regression with meters on 6MWT and number of chair stands as final predictors. Results: After controlling for demographic and psychological factors, aerobic capacity on 6MWT significantly predicted CWB pain ratings (R2 change= 22.5%, Beta= -0.491), pain facilitation during TS trials at 44°C (R2 change= 16.7%, Beta= -0.446), and the amount of pain reduction following isometric exercise (R2 change= 20.7%, Beta= 0.393). All other analyses were not significant (P>0.05). Conclusions: Older adults exhibiting greater functional aerobic capacity displayed reduced cold pain sensitivity, reduced pain facilitory function, and increased pain inhibition following exercise. These findings suggest that increased aerobic fitness in older adults may be associated with more effective endogenous modulation of pain. This study was funded by the IUPUI School of PETM Faculty Research Opportunity Grant

Increased Sensitivity to Physical Activity in Healthy Older Adults Predicts Worse Pain and Functional Outcomes

poster abstractPrior research indicates older adults with knee osteoarthritis (OA) have increased sensitivity to physical activity (SPA) and respond to physical activities of stable intensity with increases in pain. SPA predicted self-reported pain and function in older adults with knee OA. It is unknown whether SPA is present in healthy older adults without chronic pain and predicts functional outcomes. The purpose of this study was to determine if SPA in response to a standardized 6-minute Walk Test cross-sectionally predicted selfreported pain, physical function, and physical activity behaviors in healthy older adults. Forty-two older adults (age=67.5±5 years) completed the Pain subscale of the Quality of Well Being scale (QWB–measures the frequency and severity of pain during common daily activities), the Short Form Health Survey (SF-36–measure of physical function), the 6-Minute Walk Test (6MWT), and wore an accelerometer on the hip for 7 days. Subjects rated overall bodily discomfort (0-100 scale) prior to and during each minute of the 6MWT. RPE was recorded at the end of the walk. An SPA index was created by subtracting the initial bodily discomfort ratings from the peak ratings. Average moderate to vigorous physical activity/day (MVPA) and steps/day were recorded from the accelerometer. Dependent variables were analyzed with hierarchical linear regressions with SPA as the final predictor. Sixty percent of older adults experienced SPA (SPA=9.5±15.6). After accounting for age, sex, BMI, and meters walked on the 6MWT, SPA significantly predicted steps and MVPA per day, RPE on the 6MWT, and severity and frequency of activity related pain on the QWB scale. These results revealed that increased SPA in healthy older adults was associated with fewer steps and MVPA per day, greater exertion on 6MWT, and greater self-reported activity-related pain. This study was funded by the IUPUI School of PETM Faculty Research Opportunity Grant

Active Gaming as a Form of Exercise to Induce Hypoalgesia

Objective: An acute bout of moderate-to-vigorous exercise temporarily reduces pain sensitivity in healthy adults. Recently, active gaming has been rising in popularity as a means of light-to-moderate exercise and may be particularly suitable for deconditioned individuals. Whether the physical activity elicited in active games can produce a hypoalgesic effect remains unknown. The purpose of this study was to determine whether active videogames can reduce pressure and heat pain sensitivity in healthy adults. We also evaluated the relationship between the physical activity elicited by the games and the magnitude of the hypoalgesic response. Materials and Methods: Twenty-one healthy adults played four different active games on separate days, including Microsoft® Kinect Xbox® One's Fighter Within and Sports Rival's Tennis, and Nintendo® Wii™ Sports' Boxing and Tennis. Heat pain thresholds on the forearm and pressure pain thresholds (PPTs) on the trapezius and forearm were assessed immediately before and after a 15-minute active gaming or control session. Minutes spent in sedentary time and moderate-to-vigorous physical activity (MVPA) during active gaming were measured with an accelerometer. Results: The analyses revealed that PPTs at the forearm and trapezius significantly increased from pretest to posttest following Kinect Fighter Within. PPTs at the trapezius also significantly increased from pretest to posttest following Wii Boxing. The magnitude of the hypoalgesic response was significantly correlated with MVPA and sedentary time during gameplay. Conclusion: These results suggest that an active gaming session played at a moderate intensity is capable of temporarily reducing pain sensitivity

The Effect of Active Gaming on Pressure Pain Sensitivity

poster abstractAn acute bout of moderate to vigorous exercise temporarily reduces pain sensitivity in healthy adults, a phenomenon termed exercise-induced hypoalgesia (EIH). Recently, active gaming, which allows an individual to be physically active during video game play, has been rising in popularity as a means of light to moderate exercise. While evidence has shown that active gaming elicits positive cardiovascular and balance outcomes, no research has investigated active gaming as a modifier of pain. The purpose of this study was to determine whether an acute bout of active gaming increases pressure pain thresholds (PPT) in healthy adults. Fourteen young adults were enrolled in this study. Participants completed a training session and four experimental sessions. During each session, participants played one of the following active games for 15 minutes: Kinect Boxing, Kinect Tennis, Wii Boxing, and Wii Tennis. Pressure pain thresholds were measured on the trapezius muscle and the forearm before and immediately after a 15-minute active gaming session. Heart rate was also measured during game play. PPT data was analyzed with repeated measures ANOVA. Bivariate correlations examined the relationship between average percentage of heart rate reserve (HRR%) during game play and magnitude of pain reduction (post– pre). The results showed that PPTs 1) on the forearm and trapezius muscle significantly increased from pre to posttest during the Kinect Boxing session, 2) increased on the trapezius muscle during the Wii Boxing session, and 3) decreased on the forearm during the control session (p’s<.05). Greater HRR% during game play was associated with greater pain reduction (trapezius r=.33; forearm r=0.28; p’s<.05). In conclusion, active games played at a moderate intensity appear to be capable of temporarily reducing pressure pain sensitivity. This study was sponsored by the NIFS Student Research Fund

The Effect of Active Gaming on Cardiovascular Outcomes

poster abstractThe U.S. society has become more accustomed to a sedentary lifestyle in the past few decades, partially due to increased time spent in front of a screen. Recently, active gaming, which allows an individual to be physically active during video game play, has been rising in popularity as a means of exercise. However, more research is needed to evaluate whether active gaming can produce cardiovascular responses that fall within the recommended ranges for daily physical activity given by the American College of Sports Medicine (40-60% of heart rate reserve (HRR)). The purpose of this study was to determine the effects of active gaming on cardiovascular outcomes and enjoyment. Nine young adults have been enrolled in this study and data collection is ongoing. Participants completed a training session and four experimental sessions. During each session, participants played one of the following active games at a self-selected intensity for 15 minutes. Heart rate (HR) and rate of perceived exertion (RPE) were measured during game play. Enjoyment was assessed on a 10-cm VAS after each game. Repeated measures ANOVAs were used to determine differences in HRR%, RPE, and enjoyment between games. The results showed that HRR% was greater for Kinect boxing (M=42.7±12.5) compared to all other games (p=.012; Kinect Tennis=35.4±10.7, Wii Boxing=31.8±14.5, Wii Tennis=35.4±10.8). RPE was significantly greater for Kinect Boxing (M=11.3±2.0) compared to Wii Tennis (M=9.67±1.5), p=.038. Enjoyment levels did not differ between games, p=.58 (Kinect Boxing=6.6±2.1, Kinect Tennis=7.1±1.2, Wii Boxing=5.9±0.8, Wii Tennis=6.9±0.9). In conclusion, the active games played at a self-selected intensity were perceived as moderately to highly enjoyable and were able to increase cardiovascular responses. However, the intensity of activity depended on the game. Participants achieved a moderate intensity level (i.e., 40-60% of HRR) while playing Kinect Boxing, but only achieved a light intensity level while playing the other games. Mentor: Kelly M. Naugle, Department of Kinesiology, School of Physical Education, Tourism, and Management, IUPU

The Decline of Endogenous Pain Modulation With Aging: A Meta-Analysis of Temporal Summation and Conditioned Pain Modulation

The purpose of this article was to examine age-related changes in conditioned pain modulation (CPM) and temporal summation (TS) of pain using meta-analytic techniques. Five electronic databases were searched for studies, which compared measures of CPM and TS among healthy, chronic pain-free younger, middle-aged, and older adults. Eleven studies were included in the final review for TS and 11 studies were included in the review of CPM. The results suggested a moderate magnitude of difference in TS among younger and middle-aged/older adults, with the older cohorts exhibiting enhanced TS of pain. Considerable variability existed in the magnitude of the effect sizes, which was likely due to the different experimental methodologies used across studies (ie, interstimulus interval, stimulus type, and body location). In regards to CPM, the data revealed a large magnitude of difference between younger and older adults, with younger adults exhibiting more efficient pain inhibition. Differences in CPM between middle-aged and older adults were minimal. The magnitude of pain inhibition during CPM in older adults may depend on the use of concurrent versus nonconcurrent protocols. In summary, the data provided strong quantitative evidence of a general age-related decline in endogenous pain modulatory function as measured by TS and CPM

Effect of different Kinesio tape tensions on experimentally-induced thermal and muscle pain in healthy adults

Athletes and rehabilitation specialists have used Kinesio tape (KT) to help alleviate pain symptoms. Currently, no clear mechanism exists as to why pain is relieved with the use of KT and whether the pain relieving effect is simply a placebo effect. Additionally, the most effective taping parameters (tension of tape) for pain reduction remain unknown. We used quantitative sensory testing to address these key gaps in the KT and pain literature. Using a repeated-measures laboratory design, we examined whether KT applied at different tensions reduces experimentally-induced pain compared to a no tape condition and KT with minimal tension. Heat pain thresholds (HPT's), pressure pain thresholds (PPT's), and pressure pain suprathreshold (PPS: 125% of PPT) tests were administered to the forearm prior to and during KT and no tape conditions. Tape was applied to the ventral forearm at 25% of max tension, 75% of max tension, and no tension (placebo). Repeated measures ANOVA's evaluated the pain outcomes between conditions and across time. KT had no significant effect on PPT's and HPT's (p's >0.05). The ANOVA on PPS revealed that KT applied at 25% of tension significantly reduced pain ratings from the pretest (M = 34.4, SE = 5.5) to post-test 1 (M = 30.3, SE = 4.7) and post-test 2 (M = 30.4, SE = 4.7). No other conditions significantly reduced suprathreshold pressure pain. However, pain ratings at posttest-1 during the no-tape condition (M = 36.4, SE = 5.3) were significantly greater than pain ratings during post-test 1 and post-test 2 of all three tape conditions. In conclusion, the current study revealed that KT applied at low tension is the optimal tension to reduce pressure-evoked muscle pain. Additionally, the results suggested that KT applied at low, high, or no tension may acutely prevent increased muscle sensitivity with repeated pressure stimulation

Loss of Temporal Inhibition of Nociceptive Information Is Associated With Aging and Bodily Pain

An age-related decline in endogenous pain inhibitory processes likely places older adults at an increased risk for chronic pain. Limited research indicates that older adults may be characterized by deficient offset analgesia, an inhibitory temporal sharpening mechanism that increases the detectability of minor decreases in noxious stimulus intensity. The primary purpose of the study was to examine age differences in offset analgesia in community-dwelling younger, middle-aged, and older adults. An additional aim of the study was to determine whether the magnitude of offset analgesia predicted self-reported bodily pain. Eighty-seven younger adults, 42 middle-aged adults, and 60 older adults completed 4 offset analgesia trials and 3 constant temperature trials in which a noxious heat stimulus was applied to the volar forearm for 40 seconds. The offset trials consisted of 3 continuous phases: an initial 10-second painful stimulus, either a 1.0°C or .4°C increase in temperature from the initial 10-second painful stimulus for 10 seconds, and either a 1.0°C or .4°C decrease back to the initial testing temperature for 20 seconds. During each trial, subjects rated pain intensity continuously using an electronic visual analog scale (0–100). All subjects also completed the Short-Form Health Survey-36 including the Bodily Pain subscale. The results indicated that older and middle-aged adults showed reduced offset analgesia compared with younger adults in the 1.0°C and .4°C offset trials. Furthermore, the magnitude of offset analgesia predicted self-reported bodily pain, with those exhibiting reduced offset analgesia reporting greater bodily pain. Dysfunction of this endogenous inhibitory system could increase the risk of developing chronic pain for middle-aged and older adults. Perspective Older and middle-aged adults showed reduced offset analgesia compared with younger adults. The significant association between reduced offset analgesia and pain in daily life supports the notion that pain modulatory deficits are associated with not just a chronic pain condition but with the experience of pain in general

Novel method for assessing age-related differences in the temporal summation of pain

Temporal summation (TS) of pain protocols typically involve the delivery of brief repetitive noxious stimuli held at a constant intensity and measuring the consequent increase in the perceived intensity of pain sensations. To date, no studies have examined the effect of a TS protocol on the perceived spatial dimensions of the pain experience and its interaction with age. This study used a new TS protocol that examined changes in the perceived size of the painful area in 22 younger adults and 20 older adults. Four trials of ten brief heat pulses delivered at a constant intensity were administered on the volar forearm. Interpulse intervals (IPIs) were 2.5 seconds or 3.5 seconds. Subjects rated the peak pain intensity (trials 1 and 3) or the size of the painful area (trials 2 and 4) after each pulse on a 0-100 scale. The magnitude of summation was calculated for each trial. Three seconds and 6 seconds after delivering the last heat pulse, the subjects rated the intensity or the size of any remaining pain (aftersensations). The results indicated that older adults compared to younger adults exhibited significantly greater summation of size ratings for the 2.5-second and 3.5-second IPI trials and size of pain aftersensations at 3 seconds following the 2.5-second IPI TS trial. These results suggest that aging is associated with enhanced endogenous facilitation of the perceived size of pain. The potential clinical and mechanistic implications of enhanced TS of size of pain remain unknown and warrant further investigation