CORE MUSCLE ACTIVATION DURING DYNAMIC UPPER LIMB EXERCISES IN WOMEN
ABSTRACT Although several everyday functions and sporting activities demand controlled use of the abdominal and back muscles while working with the upper limbs, the activity of core muscles during dynamic upper limb exercises in the standing position has not been studied extensively. The purpose of this cross-sectional study was to examine abdominal and back muscle activity during dynamic upper limb exercises while standing and to evaluate whether dynamic exercises are appropriate for strengthening muscles. The activation of the rectus abdominis, obliquus externus abdominis, longissimus, and multifidus muscles during dynamic bilateral or unilateral shoulder exercises with or without fixation of the pelvis was measured in 20 healthy women using surface electromyography (EMG). Trunk muscle activation during isometric maximum contraction was used as a comparative reference. With bilateral shoulder extension and unilateral shoulder horizontal adduction, abdominal muscle activity was more than 60% of activity during reference exercises. With unilateral shoulder horizontal abduction and shoulder extension exercises, back muscle activity was more than 60% of the activity level reference exercise. Muscle activation levels were 35-64% lower during shoulder horizontal adduction and abduction without fixation compared to exercises with fixation. The results indicate that upper limb exercises performed in the standing position are effective for activating core muscles. Bilateral and unilateral shoulder extension and unilateral shoulder horizontal abduction and adduction with the pelvis fixed elicited the greatest activity of the core muscles.
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ABSTRACT: Lumbar spine fusion (LSF) effectively decreases pain and disability in specific spinal disorders; however, the disability rate following surgery remains high. This, combined with the fact that in Western countries the number of LSF surgeries is increasing rapidly it is important to develop rehabilitation interventions that improve outcomes. In the present RCT-study we aim to assess the effectiveness of a combined back-specific and aerobic exercise intervention for patients after LSF surgery. One hundred patients will be randomly allocated to a 12-month exercise intervention arm or a usual care arm. The exercise intervention will start three months after surgery and consist of six individual guidance sessions with a physiotherapist and a home-based exercise program. The primary outcome measures are low back pain, lower extremity pain, disability and quality of life. Secondary outcomes are back function and kinesiophobia. Exercise adherence will also be evaluated. The outcome measurements will be assessed at baseline (3 months postoperatively), at the end of the exercise intervention period (15 months postoperatively), and after a 1-year follow-up. The present RCT will evaluate the effectiveness of a long-term rehabilitation program after LSF. To our knowledge this will be the first study to evaluate a combination of strength training, control of the neutral lumbar spine position and aerobic training principles in rehabilitation after LSF. ClinicalTrials.gov Identifier NCT00834015.BMC Musculoskeletal Disorders 07/2012; 13(1):123. DOI:10.1186/1471-2474-13-123 · 1.90 Impact Factor
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ABSTRACT: Lumbar spine fusion (LSF) has been reported to change the biomechanics of the spine and therefore the rehabilitation after LSF is important. In the present study the effect of selected neutral spine control (NSC) exercises on activation of trunk muscles after LSF were evaluated. Muscle activity was measured by surface electromyography of the rectus abdominis, external oblique, longissimus, and multifidus muscles during six exercises in 22 LSF patients (mean age 59 y; age range 25-84 y; 50% women). Muscle activity concurrent with trunk flexion and extension during maximal voluntary isometric contraction (MVIC) was used as a reference value. Pain during the effort was assessed with a visual analogue scale (VAS). The highest activity in the rectus abdominis muscles was measured during bilateral shoulder extension (51% of MVIC), and in the external oblique it occurred during unilateral shoulder horizontal adduction (48% of MVIC) and unilateral hip extension (46% of MVIC) exercises. The highest activation of the multifidus and longissimus muscles (60-104%) was measured during bilateral shoulder flexion and modified Roman chair exercises. The mean (standard deviation) self-reported back-pain VAS scores during exercises varied from 3 (7) to 16 (26). NSC exercises activate trunk muscles and cause minimal pain and are therefore feasible exercises for home-based training to improve muscle endurance and postural control after LSF. In addition, the level of muscle activity during bilateral shoulder flexion and modified Roman chair exercises was over 60% of MVIC, justifying their use in training for strength of the trunk extensor muscles.The Journal of Strength and Conditioning Research 12/2013; DOI:10.1519/JSC.0000000000000334 · 1.86 Impact Factor
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ABSTRACT: Little research has been reported on the effects of using different devices with resistance exercises in a water environment. This study compared muscular activation of lower extremity and core muscles during leg adduction performed at maximum velocity with drag and floating devices of different sizes. A total of 24 young men (mean age 23.20 ± 1.18 years) performed 3 repetitions of leg adduction at maximum velocity using 4 different devices (ie, large/small and drag/floating). The maximum amplitude of the electromyographic root mean square of the adductor longus, rectus abdominis, external oblique on the dominant side, external oblique on the nondominant side, and erector lumbar spinae were recorded. Electromyographic signals were normalized to the maximum voluntary isometric contraction (MVIC). Unexpectedly, no significant (P > 0.05) differences were found in the neuromuscular responses among the different devices used; the average activation of agonist muscle adequate for neuromuscular conditioning was 40.95% of MVIC. In addition, external oblique activation is greater on the contralateral side to stabilize the body (average, 151.74%; P < 0.05). Therefore, if maximum muscle activation is required, the kind of device is not relevant. Thus, the choice should be based on economic factors.The Physician and sportsmedicine 05/2014; 42(2):80-7. DOI:10.3810/psm.2014.05.2060 · 1.49 Impact Factor