Overview of Training Research With Loading in Unstable Conditions / Pregled istraživanja treninga sa opterećenjem pri nestabilnim uslovima

The main goal of this research was to review the works that dealt with the effects of strength training in unstable conditions. A transparent survey covered 24 papers that were not older than 10 years. The sample of respondents are young and middle age groups due to similar abilities. Out of 24 papers: 16 papers were with one group in the experiment, 6 papers were with two groups in the experiment and 2 with three groups in the experiment. After the involvement of the musculature: 9 papers treated pectoral musculature, in 10 papers the involvement of the muscles of the lower limbs was processed, 6 papers dealt with the aspect of engaging the back musculature and the same abdomen, 8 papers treated chest musculature and two papers included shoulder musculature in their research. There was no difference in the degrees of promotion on the basis of gender in the articles. The statistical effect of exercise on unstable substrates was expressed in 13 studies, there were no statistically significant effects in 7 studies, while the same effect of the effects achieved by strength exercises on unstable and stable surfaces was found in 4 papers. The work done primarily suggests a positive effect of exercise on unstable substrates in untrained individuals.

Shoulder Muscular Fatigue From Static Posture Concurrently Reduces Cognitive Attentional Resources

Objective The goal of this work is to determine whether muscular fatigue concurrently reduces cognitive attentional resources in technical tasks for healthy adults. Background Muscular fatigue is common in the workplace but often dissociated with cognitive performance. A corpus of literature demonstrates a link between muscular fatigue and cognitive function, but few investigations demonstrate that the instigation of the former degrades the latter in a way that may affect technical task completion. For example, laparoscopic surgery increases muscular fatigue, which may risk attentional capacity reduction and undermine surgical outcomes. Method A total of 26 healthy participants completed a dual-task cognitive assessment of attentional resources while concurrently statically fatiguing their shoulder musculature until volitional failure, in a similar loading pattern observed in laparoscopic procedures. Continuous and discrete monitoring task performance was recorded to reflect attentional resources. Results Electromyography of the anterior deltoid and descending trapezius, as well as self-assessment surveys indicated fatigue occurrence; continuous tracking error, tracking velocity, and response time significantly increased with muscular fatigue. Conclusion Muscular fatigue concurrently degrades cognitive attentional resources. Application Complex tasks that rely on muscular and cognitive performance should consider interventions to reduce muscular fatigue to also preserve cognitive performance.

Suprascapular Neuropathy

Suprascapular neuropathy results from a lesion affecting the suprascapular nerve and is typically due to compression or traction in association with other injuries. The differential diagnosis of suprascapular neuropathy includes rotator cuff pathology, cervical radiculopathy, and Parsonage-Turner syndrome. Suprascapular neuropathy leads to a spectrum of clinical symptoms, including pain and selected weakness in shoulder abduction and external rotation of the arm. Atrophy of the shoulder musculature affecting the spinati muscles (supraspinatus and infraspinatus) often becomes apparent after some months. Suprascapular neuropathy is a challenging diagnosis to make based on the history and physical examination alone, especially since shoulder pain is relatively common and multifactorial; in addition, suprascapular neuropathy can often coexist with other shoulder pathology. The indications for a surgical procedure are the failure of nonoperative management, with lack of clinical or electrical improvement in 6 to 9 months, and the presence of a space-occupying lesion causing compression of the suprascapular nerve. Direct nerve decompression by release of the suprascapular ligament is typically recommended in cases of symptomatic isolated suprascapular neuropathy.

The Influence of Verbal and Tactile Feedback on Electromyographic Amplitude of the Shoulder Musculature During Common Therapeutic Exercises

Context:Verbal and tactile feedback (VTF) during rehabilitation exercises can increase muscle activation, thus improving the therapeutic benefits. However, it is unclear which feedback method elicits the greatest electromyographic (EMG) amplitude.Objective:To determine if the addition of tactile to verbal feedback (VF) increases EMG amplitude of selected shoulder musculature during scapular plane elevation (Ys), shoulder horizontal abduction with external rotation (Ts), and scapular retraction with external rotation (Ws).Design:Repeated-measures cross-over design.Setting:Biomechanics laboratory.Participants:A total of 30 physically active adults volunteered for this study—age = 20.23 (1.25) years; height = 1.71 (0.073) m; and mass = 70.11 (15.14) kg.Interventions:Electromyography of the serratus anterior; upper, middle, and lower trapezii; and anterior and posterior deltoids was recorded during Ys, Ts, and Ws with VTF and VF alone during separate testing sessions. Participants completed baseline trials without feedback, then received VTF and VF across 2 counterbalanced sessions.Main Outcome Measures:Difference scores were calculated between prefeedback and postfeedback interventions, and the difference score between baseline measurements was used as a control. One-way analysis of variance of the difference scores was used to evaluate the influence of VTF and VF on EMG amplitude during Ys, Ts, and Ws.Results:There was a significant difference between conditions for EMG amplitude of the middle trapezius (F2,28 = 4.09,P = .02) and serratus anterior (F2,28 = 3.91,P = .03) during Ys, the middle trapezius (F2,28 = 7.82,P = .001) during Ws, and the upper (F2,28 = 3.61,P = .03) and middle trapezii (F2,28 = 5.81,P = .01) during Ts. Post hoc testing revealed that both feedback conditions elicited greater EMG amplitude compared with no feedback, but there were no significant differences between the feedback conditions.Conclusions:The addition of tactile feedback to VF does not increase EMG amplitude compared with VF alone. This study indicates that feedback, regardless of type, is more beneficial than providing no feedback, for increasing EMG amplitude.

Normative reference values for strength and flexibility of 1,000 children and adults

Objective:To establish reference values for isometric strength of 12 muscle groups and flexibility of 13 joint movements in 1,000 children and adults and investigate the influence of demographic and anthropometric factors.Methods:A standardized reliable protocol of hand-held and fixed dynamometry for isometric strength of ankle, knee, hip, elbow, and shoulder musculature as well as goniometry for flexibility of the ankle, knee, hip, elbow, shoulder, and cervical spine was performed in an observational study investigating 1,000 healthy male and female participants aged 3–101 years. Correlation and multiple regression analyses were performed to identify factors independently associated with strength and flexibility of children, adolescents, adults, and older adults.Results:Normative reference values of 25 strength and flexibility measures were generated. Strong linear correlations between age and strength were identified in the first 2 decades of life. Muscle strength significantly decreased with age in older adults. Regression modeling identified increasing height as the most significant predictor of strength in children, higher body mass in adolescents, and male sex in adults and older adults. Joint flexibility gradually decreased with age, with little sex difference. Waist circumference was a significant predictor of variability in joint flexibility in adolescents, adults, and older adults.Conclusions:Reference values and associated age- and sex-stratified z scores generated from this study can be used to determine the presence and extent of impairments associated with neuromuscular and other neurologic disorders, monitor disease progression over time in natural history studies, and evaluate the effect of new treatments in clinical trials.