Muscular loads associated with floor vacuuming with cordless stick cleaners

Author(s):  
Yujin Kwon ◽  
Gwanseob Shin

The muscular loads of the upper extremity and chest muscles were assessed during floor vacuuming with stick vacuum cleaners. Ten participants conducted vacuuming with two stick cleaners (weight: 3.03 kg, 3.56 kg) on tiled and carpeted floors while the myoelectric activity of the upper extremity and chest muscles were collected. The mean muscle activation levels ranged from 15.5% to 45.7% of the maximum voluntary capacity. Greater muscular loads were observed on the forearm and shoulder muscles when vacuuming with repeated curved strokes (vs. straight storkes), and on the chest muscle when vacuuming the carpeted floor. The range of muscular loads were higher than that of occupational tasks such as house painting and dental drilling, which have been known as intensive activities for upper extremities. The results suggest that floor vacuuming with stick vacuum cleaners is physically demanding for household consumers. Ergonomic interventions such as more user-friendly design should be considered.

2022 ◽  
Author(s):  
Yuki Yoshida ◽  
Noboru Matsumura ◽  
Yoshitake Yamada ◽  
Satoshi Hiraga ◽  
Kazunori Ishii ◽  
...  

Abstract Background: Though alignment of the spine and lower extremities in the standing neutral position has been evaluated, a few studies evaluating the alignment of the upper extremities have also been made. This study assessed the normal alignment of the upper extremities in the standing neutral position and clarified the three-dimensional angular rotations of the upper extremity joints.Methods: Computed tomography (CT) images of 158 upper extremities from 79 healthy volunteers were prospectively acquired in the standing neutral position using an upright CT scanner. Three-dimensional coordinate systems of the thorax, scapula, humerus, and forearm were designated, and three-dimensional angular rotations of the scapulothoracic, glenohumeral, and elbow joints were calculated.Results: The mean angle of the scapulothoracic joint was 8.5° ± 5.9° of upward rotation, 28.7° ± 5.9° of internal rotation, and 7.9° ± 5.2° of anterior inclination. The mean angle of the glenohumeral joint was 4.4° ± 5.9° of abduction, 9.4° ± 12.3° of internal rotation, and 0.3° ± 4.4° of extension. The mean angle of the elbow joint was 9.6° ± 3.7° of valgus, 88.8° ± 14.3° of pronation, and 15.4° ± 4.2° of flexion. Correlations in angular rotation values were found, and interactions for keeping the upper extremities in a neutral position were observed.Conclusions: This study clarified the three-dimensional angular rotation of upper extremity joints in the standing neutral position using an upright CT scanner. Our results may provide important insights for the functional evaluation of upper extremity alignment.


2021 ◽  
pp. 074880682110310
Author(s):  
Angelo Cuzalina ◽  
Pasquale G. Tolomeo

The aim of this study was to determine the efficacy of cool atmospheric plasma (Renuvion/J-plasma) in promoting skin tightening and soft tissue contouring following liposuction of the upper extremities. The study was a retrospective review of upper extremity liposuction with associated Renuvion therapy performed by the same surgeon. Patients were made aware of Renuvion therapy to assist with skin laxity and offered adjunctive treatment following liposuction. While a majority of patients elected to have Renuvion therapy performed bilaterally, a small subset of patients elected for unilateral treatment. This subset of patients pursued delayed treatment on the control side. The inclusion criteria for the study included patients with moderate fat excess of the upper extremity with associated mild to moderate cutaneous laxity. Exclusion criteria for the study included severe medical comorbidities, body mass index greater than 35 kg/m2 and those below the age of 30. The study included 5 female patients between the ages of 46 to 52. The method of treatment was liposuction of the bilateral upper extremities with removal of equal proportions of fat. The recipient site for Renuvion treatment was randomly selected by the study coordinator; the surgeon and clinical staff remained blinded to the selection. Following treatment, the patients were evaluated at 1 week, 6 weeks, and 6 months postoperatively to assess surgical outcomes subjectively. The surgeon and clinical staff were unblinded at the final visit. Patients were evaluated based on subjective criteria and photographic evaluation at each postoperative visit. At the 1-week visit, no significant differences were noted in all subjects. At the 6-week visit, two patients demonstrated improved results to the treatment site when compared with the control site. At the 6-month visit, four out of the five patients demonstrated a significant improvement in contour and laxity at the treatment site when compared with the control site. One patient demonstrated equal results on both treatment and control sites with no major abnormalities. Following the final evaluation, the patients underwent a secondary procedure to the control site with Renuvion to obtain similar results as the recipient site. One patient demonstrated equal results on both test and control sites with no major abnormalities. The use of plasma energy via Renuvion in conjunction with liposuction has demonstrated esthetic results with proposed long-term benefits. The plasma energy device, as an adjuvant therapy, may be beneficial in cases where liposuction alone may not address tissue laxity concerns. Additional studies with a larger sample size, objective criteria, and extended follow-ups are necessary to statistically analyze the results and determine its significance.


2021 ◽  
Vol 11 (5) ◽  
pp. 2035
Author(s):  
Joseph Mizrahi

A combination of factors exposes musicians to neuro-musculoskeletal disorders, which lead to pain and damage. These involve overuse due to long playing hours, containing repetitive movements under stressful conditions, usually performed in an unnatural posture. Although the evoked disorders are usually non-traumatic, they may often lead to prolonged or even permanent damage. For instance, in upper string players, these include bursitis and tendinopathies of the shoulder muscles, tendonitis of the rotator cuff, injury at the tendon sheaths, medial or lateral epicondylitis (also known as tennis elbow), myofascial pain, and wrist tendonitis (also known as carpal tunnel syndrome, or De Quervein’s syndrome). In cases of intensive performance, a traumatic injury may result, requiring drastic means of intervention such as surgery. It should be pointed out that the upper body and upper extremities are the most commonly affected sites of playing musicians. This review provides a description of the playing-related motor disorders in performing musicians, and of the methodologies used to identify and evaluate these disorders, particularly for violinists and other upper string players.


Biomechanics ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 202-213
Author(s):  
Harish Chander ◽  
Sachini N. K. Kodithuwakku Arachchige ◽  
Alana J. Turner ◽  
Reuben F. Burch V ◽  
Adam C. Knight ◽  
...  

Background: Occupational footwear and a prolonged duration of walking have been previously reported to play a role in maintaining postural stability. The purpose of this paper was to analyze the impact of three types of occupational footwear: the steel-toed work boot (ST), the tactical work boot (TB), and the low-top work shoe (LT) on previously unreported lower extremity muscle activity during postural stability tasks. Methods: Electromyography (EMG) muscle activity was measured from four lower extremity muscles (vastus medialis (VM), medial hamstrings (MH), tibialis anterior (TA), and medial gastrocnemius (MG) during maximal voluntary isometric contractions (MVIC) and during a sensory organization test (SOT) every 30 min over a 4 h simulated workload while wearing ST, TB, and LT footwear. The mean MVIC and the mean and percentage MVIC during each SOT condition from each muscle was analyzed individually using a repeated measures ANOVA at an alpha level of 0.05. Results: Significant differences (p < 0.05) were found for maximal exertions, but this was limited to only the time main effect. No significant differences existed for EMG measures during the SOT. Conclusion: The findings suggest that occupational footwear type does not influence lower extremity muscle activity during both MVIC and SOT. Significantly lower muscle activity during maximal exertions over the course of the 4 h workload was evident, which can be attributed to localized muscular fatigue, but this was not sufficient to impact muscle activity during postural stability tasks.


1999 ◽  
Vol 91 (5) ◽  
pp. 885-888 ◽  
Author(s):  
Yasushi Miyagi ◽  
Fumio Shima ◽  
Katsuya Ishido ◽  
Masashi Moriguchi ◽  
Kazufumi Kamikaseda

✓ This 49-year-old man gradually developed a disabling action tremor in the proximal right upper extremity 8 months after suffering a pontine tegmental hemorrhage. The intraoperative microrecording in the nucleus ventralis intermedius (VIM) of the left thalamus revealed tremor-synchronous grouped discharges with a vigorous (2.7 Hz) action tremor predominantly in the shoulder and upper arm. High frequency electrical stimulation in the VIM did not affect the tremor. A posteroventral pallidotomy (PVP) was performed and resulted in the successful alleviation of all tremor activity. Posteroventral pallidotomy is known to alleviate parkinsonian tremors, especially those occurring in the contralateral lower extremity, trunk, and proximal segment of the contralateral upper extremity. The authors consider the pallidoreticular pathway to be an important tremor-mediating pathway for the proximal segment of the upper extremities and believe it can be controlled more effectively by PVP than by VIM thalamotomy, as demonstrated by the PVP-induced resolution of the midbrain tremor observed in this case.


2014 ◽  
Vol 49 (3) ◽  
pp. 317-321 ◽  
Author(s):  
Yen-Po Huang ◽  
You-Li Chou ◽  
Feng-Chun Chen ◽  
Rong-Tyai Wang ◽  
Ming-Jer Huang ◽  
...  

Context: Bench-press exercises are among the most common form of training exercise for the upper extremity because they yield a notable improvement in both muscle strength and muscle endurance. The literature contains various investigations into the effects of different bench-press positions on the degree of muscle activation. However, the effects of fatigue on the muscular performance and kinetics of the elbow joint are not understood fully. Objective: To investigate the effects of fatigue on the kinetics and myodynamic performance of the elbow joint in bench-press training. Design: Controlled laboratory study. Setting: Motion research laboratory. Patients or Other Participants: A total of 18 physically healthy male students (age = 19.6 ± 0.8 years, height = 168.7 ± 5.5 cm, mass = 69.6 ± 8.6 kg) participated in the investigation. All participants were right-hand dominant, and none had a history of upper extremity injuries or disorders. Intervention(s): Participants performed bench-press training until fatigued. Main Outcome Measure(s): Maximal possible number of repetitions, cycle time, myodynamic decline rate, elbow-joint force, and elbow-joint moment. Results: We observed a difference in cycle time in the initial (2.1 ± 0.42 seconds) and fatigue (2.58 ± 0.46 seconds) stages of the bench-press exercise (P = .04). As the participants fatigued, we observed an increase in the medial-lateral force (P = .03) and internal-external moment (P ≤ .04) acting on the elbow joint. Moreover, a reduction in the elbow muscle strength was observed in the elbow extension-flexion (P ≤ .003) and forearm supination-pronation (P ≤ .001) conditions. Conclusions: The results suggest that performing bench-press exercises to the point of fatigue increases elbow-joint loading and may further increase the risk of injury. Therefore, when clinicians design bench-press exercise regimens for general athletic training, muscle strengthening, or physical rehabilitation, they should control carefully the maximal number of repetitions.


2021 ◽  
Vol 11 (9) ◽  
pp. 4033
Author(s):  
Ahmed Salem ◽  
Amr Hassan ◽  
Markus Tilp ◽  
Abdel-Rahman Akl

The purpose of this study was to determine the muscle activation and co-activation of selected muscles during the kettlebell single arm swing exercise. To the best of our knowledge, this is the first study investigating the muscle co-activation of a kettlebell single arm swing exercise. Nine volunteers participated in the present study (age: 22.6 ± 3.8 years; body mass: 80.4 ± 9.2 kg; height: 175.6 ± 7.5 cm). The electrical muscle activity of eight right agonist/antagonist muscles (AD/PD, ESL/RA, ESI/EO, and GM/RF) were recorded using a surface EMG system (Myon m320RX; Myon, Switzerland) and processed using the integrated EMG to calculate a co-activation index (CoI) for the ascending and descending phases. A significant effect of the ascending and descending phases on the muscles’ CoI was observed. Post hoc analyses showed that the co-activation was significantly higher in the descending phase compared to that in the ascending phase of AD/PD CoI (34.25 ± 18.03% and 24.75 ± 13.03%, p < 0.001), ESL/RA CoI (34.97 ± 17.86% and 24.19 ± 10.32%, p < 0.001), ESI/EO CoI (41.14 ± 10.72% and 30.87 ± 11.26%, p < 0.001), and GM/RF CoI (27.49 ± 12.97% and 34.98 ± 14.97%, p < 0.001). In conclusion, the co-activation of the shoulder muscles varies within the kettlebell single arm swing. The highest level of co-activation was observed in the descending phase of AD/PD and GM/RF CoI, and the lowest level of co-activation was observed during the descending phase, ESL/RA and ESI/EO CoI. In addition, the highest level of co-activation was observed in the ascending phase of ESL/RA and ESI/EO CoI, and the lowest level of co-activation was observed during the ascending phase, AD/PD and GM/RF CoI. The co-activation index could be a useful method for the interpretation of the shoulder and core muscles’ co-activity during a kettlebell single arm swing.


Neurology ◽  
2021 ◽  
pp. 10.1212/WNL.0000000000011992
Author(s):  
David J Lin ◽  
Kimberly S Erler ◽  
Samuel B Snider ◽  
Anna K Bonkhoff ◽  
Julie A DiCarlo ◽  
...  

Objective:To test the hypothesis that cognitive demands influence motor performance during recovery from acute stroke, we tested acute stroke patients on two motor tasks with different cognitive demands and related task performance to cognitive impairment and neuroanatomic injury.Methods:We assessed the contralesional and ipsilesional upper extremities of a cohort of 50 patients with weakness after unilateral acute ischemic stroke at three timepoints with two tasks: the Box & Blocks Test, a task with greater cognitive demand, and Grip Strength, a simple and ballistic motor task. We compared performance on the two tasks, related motor performance to cognitive dysfunction, and used voxel-based lesion symptom mapping to determine neuroanatomical sites associated with motor performance.Results:Consistent across contralesional and ipsilesional upper extremities and most pronounced immediately post-stroke, Box & Blocks scores were significantly more impaired than Grip Strength scores. The presence of cognitive dysfunction significantly explained up to 33% of variance in Box & Blocks performance but was not associated with Grip Strength performance. While Grip Strength performance was associated with injury largely restricted to sensorimotor regions, Box & Blocks performance was associated with broad injury outside sensorimotor structures, particularly the dorsal anterior insula, a region known to be important for complex cognitive function.Conclusions:Altogether, these results suggest that cognitive demands influence upper extremity motor performance during recovery from acute stroke. Our findings emphasize the integrated nature of motor and cognitive systems and suggest that it is critical to consider cognitive demands during motor testing and neurorehabilitation after stroke.


2017 ◽  
Vol 6 (2) ◽  
pp. 50
Author(s):  
Hongqiong Deng ◽  
Yuan Li ◽  
Hong Xie ◽  
Shiwei Li

Muscle injury mechanism should be studied to know how to prevent the muscle injuries. The purpose of this article is to construct a protecting model of shoulder injuries based on classical mechanism and kinematics in throwing sports like baseball pitching, badminton smash, volleyball smash, javelin throwing process etc, and then introduce the products design. Firstly, the biomechanics of muscle were analyzed based on Newton's classical mechanics; then a finite element analysis was used to simulate the shoulder muscles protection. Protective parameters were got to make the protective clothes; finally, the protective performance and the comfortableness has been evaluated by ten healthy participants with the mean age, height, body mass were 23.5 years (SD, 1.5), 1.75m (SD, 0.07), 60.5 kg (SD, 9.1), respectively. The throwing test including the baseball pitching, the badminton smash, the process of volleyball smash, and the javelin throwing process. Three protective clothes have been produced and all of them have a protective effect on the muscle while participants were doing the baseball pitching motion, the badminton smashes motion and the volleyball smash. And it has also met the requirement of the human body. But protecting effect each style given was different in different sports motions.


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