Rheumatol Int (2013) 33:65–70 DOI 10.1007/s00296-011-2314-z 123 ORIGINAL ARTICLE The eVect of isometric exercise of the hand on the synovial blood Xow in patients with rheumatoid arthritis measured by color Doppler ultrasound Karen Ellegaard · Søren Torp-Pedersen · Hans Lund · Kirsten Pedersen · Marius Henriksen · Bente Danneskiold-Samsøe · Henning Bliddal Received: 18 September 2011 / Accepted: 10 December 2011 / Published online: 5 January 2012  Springer-Verlag 2012 Abstract In 90% of patients with rheumatoid arthritis (RA), the joints of the hand are aVected. Studies of grip strength training have not indicated a negative eVect on dis- ease activity after training. Introduction of ultrasound Doppler (USD) to measure increased blood Xow induced by inXammation has made it possible to investigate the direct eVect on blood supply in the synovium after training. In this case–control study, 24 patients with RA with USD activity in the wrist joint participated. The USD activity was measured by the color fraction (CF) (CF = colored pix- els/total number of pixels in ROI). Twenty-four patients were assigned to an 8-week grip strength training program. At baseline and after 8 weeks of training, an USD examina- tion of the wrist joint was performed. In the training group, we measured grip strength and pain in the wrist joint. Six patients withdrew from the training because of pain or change in medication. Eighteen patients served as control group. There was a modest, not signiWcant, decrease in the CF in response to training (1.86%; P = 0.08). Grip strength increased 8.8% after training (P = 0.055). Pain in motion deceased after training (P = 0.04). No diVerence in the CF was seen between the training and control groups, neither at baseline nor at follow-up (P = 0.82 and P = 0.48). Patients withdrawing from training had a signiWcantly higher CF than the other patients (P > 0.001). The results in this study might indicate that the Xow in the synovium assessed by USD is not aVected by grip strength training. Keywords Rheumatoid arthritis · Ultrasound Doppler · Disease activity Introduction Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by inXammation of the synovial tissue [1, 2]. In 90% of patients with RA, the joints of the hand are aVected [3]. In general, patients with RA have a reduced muscle strength compared to healthy persons [4, 5]. The reduced muscle strength is also seen in the muscles of the hand [6, 7]. The reduced muscle strength may explain part of the functional impairment in patients with RA. Several studies have shown that general strengthening exercises in patients with RA do not increase the disease activity [4, 8, 9]. Likewise, studies of grip strength training of the hand have indicated that there is no negative eVect on disease activity when measured as joint pain [3, 10]. How- ever, by consequence of the previous lack of direct mea- sures of disease activity in the joints, it is still unknown whether hand exercise may cause adverse eVects such as increased disease activity in the tissues of the joints in the hand [10]. With the introduction of ultrasound Doppler (USD) imaging, an opportunity to assess disease activity in single K. Ellegaard (&) · S. Torp-Pedersen · M. Henriksen · B. Danneskiold-Samsøe · H. Bliddal The Parker Institute, Frederiksberg Hospital, Nordre Fasanvej 57, 2000 Frederiksberg, Denmark e-mail: parker@frh.regionh.dk H. Lund Institute for Sports Science and Clinical Biomechanics, Research Initiative for Physical Therapy, University of Southern Denmark, Odense, Denmark K. Pedersen ProCare ApS, Tjærevej 61, 4000 Roskilde, Denmark B. Danneskiold-Samsøe · H. Bliddal Center for Sensory-Motor Interaction, Aalborg University, Fredrik Bajers Vej 7, D3, 9220 Aalborg, Denmark