-
Journal of Sports Science & Medicine Jun 2020Push-ups are an ubiquitous resistance training exercise. While exhibiting a relatively similar upper body motion to the bench press, there are substantial differences in...
Push-ups are an ubiquitous resistance training exercise. While exhibiting a relatively similar upper body motion to the bench press, there are substantial differences in repetitions when employing similar relative loads. The objective was to examine sex-related differences in repetitions and muscle activation associated with push-ups and bench press exercises. Twenty resistance-trained participants (10 men [22 ± 6.1 years] and 10 [24 ± 5.7 years] women) performed maximum push-up and bench press repetitions with loads relative to the body mass during a push-up. Electromyographic (EMG) electrodes were positioned on the middle and anterior deltoids, triceps and biceps brachii, and pectoralis major muscles and their relative (normalized to a maximum voluntary contraction) activity was compared between the two exercises performed to task failure. Both females (3.5 ± 3.9 vs.15.5 ± 8.0 repetitions; p = 0.0008) and males (12.0 ± 6.3 vs. 25.6 ± 5.2 repetitions; p < 0.0001) performed 77.4% and 53.1% less bench press than push-up repetitions respectively. Males significantly exceeded females with both push-ups (p = 0.01) and bench press (p = 0.004) repetitions. Significant linear regression equations were found for females (r = 0.55; p = 0.03), and males (r = 0.66; p < 0.0001) indicating that bench press repetitions increased 0.36 and 0.97 for each push-up repetition for females and males respectively. Triceps (p = 0.002) and biceps brachii (p = 0.03) EMG mean amplitude was significantly lower during the push-up concentric phase, while the anterior deltoid (p = 0.03) exhibited less activity during the bench press eccentric phase. The sex disparity in repetitions during these exercises indicates that a push-up provides a greater challenge for women than men and regression equations may be helpful for both sexes when formulating training programs.
Topics: Adult; Electromyography; Female; Humans; Male; Muscle, Skeletal; Regression Analysis; Resistance Training; Sex Characteristics; Sex Factors; Young Adult
PubMed: 32390722
DOI: No ID Found -
European Journal of Sport Science 2016This study compared the muscular activation of the pectoralis major, anterior deltoid and triceps brachii during a free-weight barbell bench press performed at 0°,... (Comparative Study)
Comparative Study
This study compared the muscular activation of the pectoralis major, anterior deltoid and triceps brachii during a free-weight barbell bench press performed at 0°, 30°, 45° and -15° bench angles. Fourteen healthy resistance trained males (age 21.4 ± 0.4 years) participated in this study. One set of six repetitions for each bench press conditions at 65% one repetition maximum were performed. Surface electromyography (sEMG) was utilised to examine the muscular activation of the selected muscles during the eccentric and concentric phases. In addition, each phase was subdivided into 25% contraction durations, resulting in four separate time points for comparison between bench conditions. The sEMG of upper pectoralis displayed no difference during any of the bench conditions when examining the complete concentric contraction, however differences during 26-50% contraction duration were found for both the 30° [122.5 ± 10.1% maximal voluntary isometric contraction (MVIC)] and 45° (124 ± 9.1% MVIC) bench condition, resulting in greater sEMG compared to horizontal (98.2 ± 5.4% MVIC) and -15 (96.1 ± 5.5% MVIC). The sEMG of lower pectoralis was greater during -15° (100.4 ± 5.7% MVIC), 30° (86.6 ± 4.8% MVIC) and horizontal (100.1 ± 5.2% MVIC) bench conditions compared to the 45° (71.9 ± 4.5% MVIC) for the whole concentric contraction. The results of this study support the use of a horizontal bench to achieve muscular activation of both the upper and lower heads of the pectoralis. However, a bench incline angle of 30° or 45° resulted in greater muscular activation during certain time points, suggesting that it is important to consider how muscular activation is affected at various time points when selecting bench press exercises.
Topics: Biomechanical Phenomena; Deltoid Muscle; Electromyography; Humans; Isometric Contraction; Male; Muscle, Skeletal; Pectoralis Muscles; Upper Extremity; Weight Lifting; Young Adult
PubMed: 25799093
DOI: 10.1080/17461391.2015.1022605 -
Revista Brasileira de Ortopedia 2015To describe the clinical, electrophysiological and imaging findings from Parsonage-Turner syndrome and evaluate the results from conservative treatment.
OBJECTIVE
To describe the clinical, electrophysiological and imaging findings from Parsonage-Turner syndrome and evaluate the results from conservative treatment.
METHODS
Eight cases were studied between February 2010 and February 2012, with a minimum follow-up of one year (mean of 14 months). All the patients answered a clinical questionnaire and underwent functional evaluation using the Constant and Murley score. After clinical suspicion was raised, an electromyography examination was performed to confirm the diagnosis.
RESULTS
Eight patients (mean age of 29 years) were evaluated. The right side was affected in 70% of the cases, and the dominant side in 80% of the cases. All the patients reported that their shoulder pain had started suddenly, lasting from one to five days in six cases and up to 15 days in two cases. In three cases, severe atrophy of the deltoid muscle was observed. Hypotrophy of the supraspinatus and infraspinatus muscles was observed in three cases. A winged scapula was observed in the two remaining cases. Electromyography demonstrated involvement of the long thoracic nerve in these last two cases and confirmed the involvement of the axillary and suprascapular nerves in the remaining six cases. The mean score on the Constant and Murley scale was 96 at the end of the conservative treatment with non-steroidal anti-inflammatory drugs and physiotherapy. Six of the eight patients presented good recovery of muscle strength.
CONCLUSIONS
In the majority of the cases, the functional recovery was good, although muscle strength was not completely restored in some of them.
PubMed: 26229940
DOI: 10.1016/j.rboe.2015.04.002 -
Journal of Shoulder and Elbow Surgery Apr 2021Restoration of muscular strength is predicated on restoration of muscle length. The purpose of this study was to describe infraspinatus and deltoid length preoperative...
BACKGROUND
Restoration of muscular strength is predicated on restoration of muscle length. The purpose of this study was to describe infraspinatus and deltoid length preoperative to reverse total shoulder arthroplasty (RTSA) to guide distalization and lateralization to restore preoperative muscle length.
METHODS
This was a retrospective radiographic study. We measured the infraspinatus length on preoperative computed tomographic images and the deltoid length on preoperative radiographs. For all measurements, reliability was first established by comparing measurements between 2 observers, and intraclass correlation coefficients (ICCs) were calculated. We then calculated descriptive statistics for these muscle lengths and developed a formula to predict these muscle lengths from patient demographics.
RESULTS
We measured infraspinatus length in 97 patients and deltoid length in 108 patients. Inter-rater reliability was excellent, with all ICCs >0.886. The mean infraspinatus length was 15.5 cm (standard deviation 1.3) and ranged from 12.6-18.9 cm, whereas the deltoid length was 16.2±1.7 cm and ranged from 12.5-20.2 cm. Both infraspinatus (r = 0.775, P < .001) and deltoid length (r = 0.717, P < .001) were highly correlated with patient height but did not differ between diagnoses. Formulae developed through linear regression allowed prediction of muscle length to within 1 cm in 78% and within 2 cm in 100% for the infraspinatus and 60% and 88% for the deltoid.
CONCLUSION
Deltoid and infraspinatus length are variable but highly correlated with patient height. To maintain tension, 2 mm of lateralization and distalization should be added for every 6 inches (∼15 cm) of height above average for a Grammont-style RTSA.
Topics: Arthroplasty, Replacement, Shoulder; Deltoid Muscle; Humans; Range of Motion, Articular; Reproducibility of Results; Retrospective Studies; Rotator Cuff; Shoulder Joint
PubMed: 32711102
DOI: 10.1016/j.jse.2020.07.018 -
Orthopaedics & Traumatology, Surgery &... Feb 2018Glenoid exposure is agreed to be a difficult step, but is also a key step in total shoulder arthroplasty, both anatomic and reverse. It conditions unhindered use of the... (Review)
Review
Glenoid exposure is agreed to be a difficult step, but is also a key step in total shoulder arthroplasty, both anatomic and reverse. It conditions unhindered use of the ancillary instrumentation and thus correct glenoid component positioning. The main stages comprise arthrotomy, by opening the rotator cuff, humeral head cut, and inferior glenohumeral release, enabling shifting of the humerus and good exposure of the glenoid cavity. The two main approaches are deltopectoral and anterosuperior transdeltoid. Using the deltopectoral approach, arthrotomy is performed through the subscapularis muscle, by various techniques. This approach enables extensive inferior glenohumeral release and thus an approach to the inferior apex of the glenoid cavity, which is a key area for glenoid implant positioning. The main drawbacks are postoperative shoulder instability and limited access to the posterior part of the glenoid in case of significant retroversion. Moreover, subscapularis healing is uncertain, which can impair the clinical outcomes, with risk of glenoid component loosening. Advantages, on the other hand, include the fact that it can be implemented in all cases, even the most difficult ones, and that the deltoid muscle is respected. The transdeltoid approach has the advantage of being simple, providing direct exposure of the glenoid cavity through a rotator cuff tear after passing through the deltoid. It is therefore especially indicated for reverse prosthesis in case of rotator cuff tear, and in traumatology. However, the approach to the inferior part of the glenoid cavity can be restricted, with insufficient exposure and a risk of glenoid component malpositioning (superior tilt). The preoperative assessment is essential, to detect at-risk situations such as severe stiffness and anticipate difficulties in glenoid exposure.
Topics: Arthroplasty, Replacement, Shoulder; Deltoid Muscle; Glenoid Cavity; Humans; Humeral Head; Joint Instability; Rotator Cuff; Shoulder Prosthesis
PubMed: 29155311
DOI: 10.1016/j.otsr.2017.10.008