After normalization to the MMT, mean EMG activity for each subject and each muscle was calculated for each motion both with and without immobilization and with and without load. View or download all the content the society has access to. Juhan T, Stone M, Jalali O, Curtis W, Prodromo J, Weber AE, Hatch GF III, Omid R. Orthop Rev (Pavia). eCollection 2020 May. In addition, a dynamic role for the LHBM in glenohumeral motion does not suggest that the LHBT should be preserved in treatment of pathology of the proximal biceps tendon, biceps anchor, and superior labrum. Contact us if you experience any difficulty logging in. Data were tested for normality using the Kolmogorov-Smirnov test, and parametric/nonparametric tests were used as appropriate based on data normality. We use cookies to ensure that we give you the best experience on our website. Disorders of the tendon of the long head of the biceps brachii (LHB) are common. Thirteen subjects aged 26.2 ± 4.2 years, with a weight of 76.9 ± 15.0 kg and height of 177.8 ± 9.3 cm, participated in this study. As a negative control, nonimmobilized and immobilized brachioradialis activity was compared using the Mann-Whitney U test. 2008 Dec;33(10):1853-9. doi: 10.1016/j.jhsa.2008.07.019. Error bars represent 1 standard deviation. The long head of the biceps was instrumented with thin wire electrodes. Caufriez B, Dugailly PM, Brassinne E, Schuind F. J Hand Surg Asian Pac Vol. Mean maximal manual testing–normalized percent electromyographic (EMG) activity in the middle head of the deltoid muscle both with and without splint immobilization and both with and without elbow loading with the shoulder in the neutral position and with motion to 45° of abduction, 90° of abduction, 45° of forward flexion, and 90° of forward flexion. Mean maximal manual testing–normalized percent electromyographic (EMG) activity in the short head of the biceps muscle (SHBM) both with and without splint immobilization and both with and without elbow loading with the shoulder in the neutral position and with motion to 45° of abduction, 90° of abduction, 45° of forward flexion, and 90° of forward flexion. 12 At the shoulder joint, however, the function of this muscle is less clear. By continuing you agree to the use of cookies. Figure 3. Yamaguchi et al16 insufficiently stressed the glenohumeral joint to show this activity and thus incorrectly concluded there was no activity. TABLE 4 P Values for EMG Activity Between Splinted/Nonsplinted (Within Each Loading State) and Loaded/Nonloaded (Within Each Splinting State) Conditionsa. By continuing to browse The biceps femoris is a double-headed muscle located on the back of thigh. J Clin Orthop Trauma. Copyright © 2020 Elsevier B.V. or its licensors or contributors. We use cookies to help provide and enhance our service and tailor content and ads. Pagnani, MJ, Deng, XH, Warren, RF, Torzilli, PA, O’Brien, SJ. The supraspinatus, infraspinatus, deltoid, brachialis, and brachioradialis were instrumented as controls. The function of the LHB tendon and its role in glenohumeral kinematics presently remain only partially understood because of the difficulty of cadaveric and in vivo biomechanical studies. You can be signed in via any or all of the methods shown below at the same time. This will show the side-to-side differences with and without the effects of the LHB. Three consecutive trials of 3- to 5-second maximal manual muscle testing (MMT) were performed. To address this issue, we performed an EMG analysis of LHBM and SHBM activity during a variety of shoulder motions both with and without elbow and forearm immobilization to neutralize LHBM activity as an elbow flexor and forearm supinator. Please enable it to take advantage of the complete set of features!