PRESSURE PAIN MAPPING OF THE WRIST EXTENSORS AFTER REPEATED ECCENTRIC EXERCISE AT HIGH INTENSITY JOSE ´ M. DELFA DE LA MORENA, 1,2 AFSHIN SAMANI, 1 JOSUE ´ FERNA ´ NDEZ-CARNERO, 2 ERNST A. HANSEN, 1 AND PASCAL MADELEINE 1 1 Center for Sensory-Motor Interaction (SMI), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark; and 2 Department of Physical Therapy, Occupational Therapy, Physical Medicine and Rehabilitation, University of Rey Juan Carlos, Alcorco´n, Madrid, Spain ABSTRACT Delfa de la Morena, JM, Samani, A, Ferna ´ ndez-Carnero, J, Hansen, EA, and Madeleine, P. Pressure pain mapping of the wrist extensors after repeated eccentric exercise at high intensity. J Strength Cond Res 27(11): 3045–3052, 2013— The purpose of this study was to investigate adaptation mechanisms after 2 test rounds consisting of eccentric exer- cise using pressure pain imaging of the wrist extensors. Pres- sure pain thresholds (PPTs) were assessed over 12 points forming a 3 3 4 matrix over the dominant elbow in 12 partic- ipants. From the PPT assessments, pressure pain maps were computed. Delayed onset muscle soreness was induced in an initial test round of high-intensity eccentric exercise. The sec- ond test round performed 7 days later aimed at resulting in adaptation. The PPTs were assessed before, immediately after, and 24 hours after the 2 test rounds of eccentric exer- cise. For the first test round, the mean PPT was significantly lower 24 hours after exercise compared with before exercise (389.5 6 64.1 vs. 500.5 6 66.4 kPa, respectively; p = 0.02). For the second test round, the PPT was similar before and 24 hours after (447.7 6 51.3 vs. 458.0 6 73.1 kPa, respec- tively; p = 1.0). This study demonstrated adaptive effects of the wrist extensors monitored by pain imaging technique in healthy untrained humans. A lack of hyperalgesia, i.e., no decrease in PPT underlined adaptation after the second test round of eccentric exercise performed 7 days after the initial test round. The present findings showed for the first time that repeated eccentric exercise performed twice over 2 weeks protects the wrist extensor muscles from developing exacer- bated pressure pain sensitivity. Thus, the addition of eccentric components to training regimens should be considered to induce protective adaptation. KEY WORDS pressure pain threshold, pain imaging technique, delayed onset of muscle soreness, mechanical hyperalgesia INTRODUCTION L ateral epicondylalgia or “tennis elbow” may appear as a result of unusual or intensive repetitive exercise of the wrist extensors. In the general population, the incidence of this pathology is between 1 and 3% (30,34). Despite immense efforts, the underlying pathophysi- ology is still relatively unknown (16,18,19). Tendon pathology, mechanical hyperalgesia, and motor system impairments, e.g., muscle strength reductions, are among the known symptoms of lateral epicondylalgia (7,10). To a large extent, similar symp- toms may appear in a condition in which delayed onset of muscle soreness (DOMS) occurs. Therefore, inducing DOMS may serve as a useful experimental technique to enlarge our understanding. Unaccustomed intensive eccentric exercise is known to be effective for inducing decreased range of move- ment and muscle strength, and deep tissue hyperalgesia 24–48 hours after exercise in the affected muscle group (13,23,25). The DOMS is suggested to be caused by tissue damage and the related inflammatory response. However, this is still debated (20). An inflammatory reaction includes a release of proinflammatory substances after disruption of the muscle fibers and the connective tissue (8,21). Similar to lateral epi- condylalgia, DOMS is characterized by mechanical muscle hyperalgesia, occasional pain at rest, and altered motor control (14,22). Previously, the extensor carpi radialis brevis muscle has been proven to be the most sensitive muscle to pressure pain compared with the extensor digitorum communis and the extensor carpi ulnaris muscles (11), which is in line with clinical findings on lateral epicondylalgia (29). The symptoms related to unaccustomed eccentric exercise causing DOMS are attenuated when the same or similar eccentric exercise has been performed days or weeks before- hand (5), even at a lower intensity (17). Thus, apparently the Address correspondence to Prof. Pascal Madeleine, pm@hst.aau.dk. 27(11)/3045–3052 Journal of Strength and Conditioning Research Ó 2013 National Strength and Conditioning Association VOLUME 27 | NUMBER 11 | NOVEMBER 2013 | 3045 Copyright © National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.