Delayed Onset Muscle Soreness (DOMS) is a common myogenic pain which occurs 24 to 48 hr after unaccustomed or, in particular, eccentric exercise. It can occur in untrained people who suddenly begin to exercise or even in athletes who try to learn new training patterns (Craig et al., 1999b; Petrofsky et al., 2011). It is a benign condition which usually subsides after 3-4 days of relative inactivity. Nevertheless the symptoms of DOMS affect daily activities and athletic performance, especially in kinetotherapy, the pain and discomfort may discourage a patient from persisting in therapy or disrupt his rehabilitation progress (Douris et al., 2006; Ernst, 1998; Lau and Nosaka, 2011). Therefore, it is necessary to use some interventions to relief the symptoms of DOMS.
The mechanism of DOMS is an inflammation process which is activated by high tensile forces induced muscle strain (Douris et al., 2006). According to the mechanism of DOMS, numerous studies have investigat ed the efficacy of drug therapy (anti-inflammatory agents and oral analgesics) and physical therapy (massage, phototherapy, heat modalities, hydrotherapy, ultrasound, vibration, electrical nerve stimulation and laser and ice). However, those studies have yielded conflicting and equivocal results (Aminian-Far et al., 2011; Craig et al., 1999a; Craig et al., 1996; 1999b; Douris et al., 2006; Ernst, 1998; Lau and Nosaka, 2011; Petrofsky et al., 2011; Sellwood et al., 2007; Vaile et al., 2008). Three studies have investigated the effects of acupuncture on DOMS, one study reported that acupuncture has little effect upon the cardinal signs and symptoms of DOMS, and the other two studies both considered that acupuncture can relief muscle pain of DOMS.
Moxibustion is an oriental traditional therapeutic remedy by utilizing cauterization or heating with ignited flammable material applied to acupoints. There have been studies on the mechanism of moxibustion working on the local region of the human body. Xinmin et al. (1999) found that moxibustion could significantly change temperature from the skin to the muscle, with different patterns. An experiment has shown (Yuanhua and Tangyi, 1996) that moxa could emit near-infrared during the combustion process, which can stimulate the hydrogen bonds of the macromolecule in the acupoints, resulting in stimulated coherence resonance absorption effect, through the nerve-fluid system to transfer the energy needed by cells. Moxibustion could induce heat shock protein (HSP) (Kobayashi, 1995). Numerous clinical studies (Chen et al., 2012; Lee et al., 2010a; 2010b; Ren et al., 2011) demonstrated that moxibustion can relieve pain of muscle and joint. Also laboratory studies suggest that moxibustion has anti-inflammatory effect.
Suspended moxibustion, the indirect moxibustion, is a safe treatment technique and easy to be handled by treatment provider. Above all, it is conceivable that the suspended moxibustion could be a potential treatment for DOMS. However, there is no evidence to support this hypothesis. Therefore, the aim of the present study was to investigate the effects of suspended moxibustion upon tender point compared to sham treatment on symptoms and muscular performance in exercise-induced DOMS.
The present study was a randomized, controlled, double blinded trial to investigate the effects of suspended moxibustion upon tender point in DOMS patients.
Fifty healthy student volunteers were recruited from the Shandong Normal University. Exclusion criteria included: cardiovascular, pulmonary, metabolic, neurological, psychiatric and musculoskeletal diseases, pregnancy, history of active hemorrhaging, heat or moxibustion sensitivity, participated in an exercise strength training program within 6 months, and the use of any medications. Subjects were instructed to refrain from any form of physical exercise for at least 1 week prior to as well as during the entire study period. Any drinks containing caffeine or alcohol were forbidden during the entire study period.
Volunteers were informed of the procedures and voluntarily participate in the present study by signing a consent form. The study was approved by the Faculty of Physical Education of Shandong Normal University and followed the Declaration of Helsinki recommendations for research involving human subjects (Harriss and Atkinson, 2011).
The present study took place at the exercise science and rehabilitation laboratory of the faculty of physical education of Shandong Normal University. There are an isokinetic dynamometer which can be used to induce DOMS and several therapeutic beds which can provide an environment for moxibustion therapy.
Subjects attended the research according to their individual schedule in consecutive 4 days. On the first day, after the measurements of height, weight, maximum isometric muscle strength of nondominant elbow flexors and circumference of nondominant upper arm, each subject performed a DOMS induction protocol (See next paragraph) by an isokinetic dynamometer. Each subject received twice treatments 24 hr and 48 hr after the DOMS induction. The measurements of Pain Visual Analog Scale (Pain VAS), maximum isometric muscle strength and circumference were made immediately after DOMS induction, before and after every treatment session and 72 hr after DOMS induction.
As a preliminary study, there were no data available to determine the sample size of the present study. An inter-group difference was reported in a published study in which 40 subjects were recruited to investigate the effects of acupuncture on tender points for DOMS. Thereby, given a predicted dropout rate of 20%, we determined 50 subjects recruited in the present study, 25 people in each group
Randomized treatment Allocation
Subjects were randomly assigned following simple randomization procedures to two groups: moxibustion group and...