Does the Position of the Ankle Matter During the Single Gluteal Bridge in Futsal Players? An Electromyographic Analysis.

CONTEXT: The aim of this study was to analyze the muscle activity of the hamstring muscles and the lateral gastrocnemius during different variants of the single-leg bridge (SLB) in futsal players. DESIGN: Cross-sectional study. METHODS: Twenty-two futsal players (age = 24.8 [3.9] y) volunteered to participate in this study. The participants performed 3 variations of the SLB with the knee flexed at 45°. The first position was performed with the ankle in plantar position with flat support, the second with the ankle in dorsiflexion (DF) with heel support, and the third with the ankle in DF and external rotation (ER) with heel support. The Wilcoxon rank-sum test assessed the difference between variables for samples with the rank-biserial correlation effect size. Spearman correlation coefficients were used to examine the associations of the percentage maximal voluntary isometric contraction for each muscle with peak force and rate of force development with 3 different variances of the SLB. RESULTS: The variation of ankle DF and ER with heel support generated higher muscle activity in BF in concentric (P < .01, effect size [ES] = -0.613); isometric (P < .042, ES = -0.494); and eccentric (P < .005, ES = -0.668) contraction than ankle DF with heel support. In contrast, the variation of ankle DF and ER with heel support generated fewer muscle activity in lateral gastrocnemius in concentric (P < .001, ES = 0.779); isometric (P < .003, ES = 0.708); and eccentric (P < .014, ES = 0.589) contraction than ankle DF with heel support. CONCLUSIONS: The position of DF and ER was the best position in SLB to train the BF. It could be convenient to start rehabilitation of the BF with flat foot postition or ankle in DF with heel support and progress with the position of the ankle in DF and ER with heel support.

Overhead Shoulder Position Versus Scapular Retraction Position to Normalize the Electromyographic Signal of the Lower Trapezius Muscle.

This study aimed to compare electromyographic response of the lower trapezius muscle during maximal voluntary isometric contractions under two conditions: overhead shoulder position versus scapular position, rating the pain after each condition. Twenty-six participants with shoulder pain (SP; n = 15; Shoulder Pain and Disability Index-Pain = 34 [range 6-66]) and without shoulder pain (nSP; n = 11; Shoulder Pain and Disability Index-Pain = 0 [range 0-14]) performed maximal voluntary isometric contractions in those 2 conditions while the lower trapezius was monitored using surface electromyography. Pain was rated using the visual analog scale. The nSP group experienced no pain, whereas the SP group reported pain in both conditions with higher pain during the overhead movement. No differences were observed for muscle excitation between conditions, but higher levels were observed for the nSP group compared with the SP group. The overhead condition was more painful for the SP group (visual analog scale: SP = 4 vs nSP = 1.09, P = .036). Scapular position showed the same levels of LT excitation than overhead position. The scapular position is preferable, compared with overhead positioning, to normalize the lower trapezius instead of overhead positioning.

Acceleration Profiles and the Isoinertial Squatting Exercise: Is There a Direct Effect on Concentric-Eccentric Force, Power, and Neuromuscular Efficiency?

OBJECTIVE: To examine the selective influences of distinct acceleration profiles on the neuromuscular efficiency, force, and power during concentric and eccentric phases of isoinertial squatting exercise. DESIGN: Cross-sectional study. SETTING: Biomechanics laboratory of the university. PARTICIPANTS: A total of 38 active adults were divided according to their acceleration profiles: higher (n = 17; >2.5 m/s2) and lower acceleration group (n = 21; <2.5 m/s2). INTERVENTION: All subjects performed squats until failure attached to an isoinertial conic pulley device monitored by surface electromyography of rectus femoris, vastus medialis, vastus lateralis, biceps femoris, and semitendinosus. MAIN OUTCOME MEASURES: An incremental optical encoder was used to assess maximal and mean power and force during concentric and eccentric phases. The neuromuscular efficiency was calculated using the mean force and the electromyographic linear envelope. RESULTS: Between-group differences were observed for the maximal and mean force (Prange = .001-.005), power (P = .001), and neuromuscular efficiency (Prange = .001-.03) with higher significant values for the higher acceleration group in both concentric and eccentric phases. CONCLUSION: Distinct acceleration profiles affect the neuromuscular efficiency, force, and power during concentric and eccentric phases of isoinertial squatting exercise. To ensure immediate higher levels of power and force output without depriving the neuromuscular system, acceleration profiles higher than 2.5 m/s2 are preferable. The acceleration profiles could be an alternative to evolve the isoinertial exercise.

Effects of 8 weeks of masticatory muscles focused endurance exercises on women with oro-facial pain and temporomandibular disorders: A placebo randomised controlled trial.

BACKGROUND: Exercises are used to treat temporomandibular disorders (TMD), but they are often assessed with other therapies. Local endurance exercises may alter the resistance to fatigue and pain. OBJECTIVE: To assess the effects of an 8-week protocol of local endurance exercises of masticatory muscles on muscle excitation, force response, perceived pain and over muscle efficiency. DESIGN: Randomised controlled trial. SETTING: Ambulatory care. SUBJECTS: In a placebo randomised controlled trial, 46 women with TMD and oro-facial pain were randomised into intervention group and placebo group. The intervention group received a protocol of biting endurance exercises, controlled by biofeedback. The placebo group received a placebo (simulated laser therapy). MAIN OUTCOME MEASURES: The primary outcomes were collected at baseline, 4 weeks and 8 weeks. Pain was assessed through visual analogue scale (VAS) and pressure pain thresholds (PPT). Bite force was collected by a load cell synchronised with surface electromyography of masticatory muscles, bilaterally. RESULTS: Pain scores decreased for both groups, but the intervention group showed lower values at 8 weeks. No differences were noted between groups for PPT, but the results increased for both overtime. Time until fatigue and muscle efficiency were higher in the intervention group vs placebo group in both within- and between-subject analysis. Force increased from 4 to 8 weeks in the PG, without differences between groups. Temporal muscle excitation was higher on 8 weeks compared with baseline for the intervention group, without differences between groups. CONCLUSION: Eight-week exercise protocol of muscle endurance alleviates the pain and improves the resistance to fatigue and muscle efficiency in TMD subjects.

Activity of Lower Limb Muscles During Squat With and Without Abdominal Drawing-in and Pilates Breathing.

Barbosa, AC, Martins, FM, Silva, AF, Coelho, AC, Intelangelo, L, and Vieira, ER. Activity of lower limb muscles during squat with and without abdominal drawing-in and Pilates breathing. J Strength Cond Res 31(11): 3018-3023, 2017-The purpose of this study was to assess the effects of abdominal drawing-in and Pilates breathing on the activity of lower limb muscles during squats. Adults (n = 13, 22 ± 3 years old) with some Pilates experience performed three 60° squats under each of the following conditions in a random order: (I) normal breathing, (II) drawing-in maneuver with normal breathing, and (III) drawing-in maneuver with Pilates breathing. Peak-normalized surface electromyography of the rectus femoris, biceps femoris, gastrocnemius medialis, and tibialis anterior during the knee flexion and extension phases of squat exercises was analyzed. There were significant differences among the conditions during the knee flexion phase for the rectus femoris (p = 0.001), biceps femoris (p = 0.038), and tibialis anterior (p = 0.001), with increasing activation from conditions I to III. For the gastrocnemius medialis, there were significant differences among the conditions during the knee extension phase (p = 0.023), with increased activity under condition I. The rectus and biceps femoris activity was higher during the extension vs. flexion phase under conditions I and II. The tibialis anterior activity was higher during the flexion compared with the extension phase under all conditions, and the medial gastrocnemius activity was higher during the extension phase under condition I. Doing squats with abdominal drawing-in and Pilates breathing resulted in increased rectus, biceps femoris, and tibialis anterior activity during the flexion phase, increasing movement stability during squat exercises.

Effects of combining a high-intensity interval training programme with a standard programme on mobility and function in lower limb amputees.

High-energy expenditure during walking is one of the most important limiting factors for lower limb amputees. Although several physical training methods have been proposed to reduce energy expenditure, little is known about the effects of high-intensity interval training in lower limb amputees. This study aimed to test the effects of a 6-week high-intensity interval training protocol in subjects with lower limb amputation on walking distance, physiological cost of walking, and functional mobility. A quasi-experimental pre and post-study included 13 subjects with lower limb amputation. They performed 12 sessions of a high-intensity interval training protocol with a frequency of 2 days/week for 6 weeks. Walking distance, physiological cost of walking, and functional mobility before and after the training protocol were assessed. Walking distance increased from 204.48 to 229.09 m (P = 0.003), physiological cost of walking decreased from 0.66 to 0.31 beats/m (P = 0.001), and functional mobility improved from 30.38 to 33.61 points (P = 0.001). High-intensity interval training improved walking distance, physiological cost of walking, and functional mobility in subjects with lower limb amputation.

Reliability of two devices for shoulder strength assessment: Wii Fit Balance Board and hand-held dynamometer.

Background: The aim of this study was to compare the reliability and agreement between two devices - Wii Fit Balance Board (WBB) versus Hand-Held Dynamometer (HHD) to measure isometric strength during the athletic shoulder (ASH) test in healthy amateur rugby players. Methods: Fifteen males (23.73 ± 2.8 years) completed two testing sessions. Maximal isometric contractions using the dominant arm (D) and non-dominant arm (ND) against a WBB and HHD were assessed at three angles of abduction (180°, 'I'; 135°, 'Y' and 90°, 'T'), in a prone lying position. Results: The results indicate a very large correlation between the HHD and the WBB. WBB provides acceptable reliability at I-Test D (CV = 9.97%, ICC = 0.88) and HHD in the I-Test D (CV = 8.90%, ICC = 0.94), I-Test ND (CV = 8.60%, ICC = 0.95) in peak strength values. The HHD is most reliable in D ASH I-Y-T (CV = 10.94%) and WBB (CV = 11.05%). In the ND ASH I-Y-T test, the HHD is the most reliable (CV = 12.5%) compared to the WBB (CV = 14.43%). Conclusions: These results suggest that WBB is a reliable device to assess strength in the ASH test with a very large correlation with the HHD. WBB and HHD are two affordable devices to assess isometric shoulder strength.

Somatosensory and psychosocial profile of migraine patients: A cross-sectional study.

BACKGROUND: Migraine is a chronic neurological disorder that involves the brain, characterized by a series of abnormal neuronal networks interacting at different levels of the central and peripheral nervous system. Furthermore, it is known that psychosocial features contribute to the exacerbation and chronicity of symptoms. OBJECTIVE: To compare the somatosensory and psychosocial profiles of migraine patients with a control group. METHODS: We conducted a cross-sectional study comparing the somatosensory and psychosocial profiles of patients with migraine and healthy volunteers. A total of 52 women were included. For the somatosensory profile, Mechanical Detection Threshold (MDT), Pressure Pain Threshold (PPT), Temporal Summation (TS), and Conditioned Pain Modulation (CPM) in the trigeminal and extra-trigeminal areas were evaluated. Psychosocial profiles were assessed using questionnaires, the Central Sensitization Inventory, the Generalized Anxiety Disorders, the Pain Catastrophizing Scale, and the Tampa Scale of Kinesiophobia. Mann-Whitney U test was used to compare differences in the profiles between groups. The significance level was set at 5%. RESULTS: Migraine patients showed a loss of somatosensory function in the trigeminal area for MDT (p = 0.019, r = 0.34 and p = 0.011, r = 0.37 for the ophthalmic nerve and masseter muscle respectively), lower PPT in trigeminal and extra-trigeminal areas (p < 0.001, r=>0.60) and less efficient CPM (p < 0.001, r=>0.60). No statistically significant differences were found in the TS (p=>0.05). Statistically significant differences were found in all psychosocial variables (p = <0.001 r=>0.60). CONCLUSION: Migraine patients showed loss of somatosensory function, lower pressure pain threshold, and an inhibitory pro-nociceptive profile with high scores on central sensitization and fear of movement compared to the control group.

Evidence-based practice in physiotherapy in Argentina: Barriers, perceptions and behaviors.

BACKGROUND AND PURPOSE: Evidence-based practice (EBP) has been widely implemented in different areas of biomedical sciences. However, no precedents in Argentina have investigated the data regarding the knowledge and difficulties related to EBP in physiotherapists. The purpose was to describe the self-reported behavior, knowledge, skills, opinion, and barriers related to the EBP of Argentinian physiotherapists. METHODS: A customized descriptive survey was conducted among 289 physical therapists in Argentina. The data were analyzed descriptively. RESULTS: The response rate was 56% (163/289). Argentinian physiotherapists update themselves through scientific articles, meetings, congresses, and courses. They reported having sufficient knowledge to use EBP, informing patients about treatment options, and considering their choices in the decision-making process. However, there were inconsistencies in responses regarding experience with EBP during undergraduate or postgraduate studies. The most frequently reported barriers were lack of time, difficulty in understanding statistics, and difficulties with the English language of scientific articles. DISCUSSION: EBP in Argentine physiotherapists is still poorly understood. Time, language, and difficulties in understanding statistics are the most important barriers to the implementation of EBP. Undergraduate and postgraduate courses are warranted to improve the clinical decision-making process.

Muscle responses during radial nerve-biased upper limb neurodynamic test in asymptomatic individuals: a cross-sectional study.

This laboratory cross-sectional study aimed at explore the muscle response (MR) of the upper trapezius, infraspinatus, biceps brachii and extensor carpi radialis brevis (ECRB) during the radial nerve-biased upper limb neurodynamic test (RN-ULNT) in healthy participants. Myoelectric activity was stage-by-stage recorded during two sequencing variants of the RN-ULNT: S1, in which elbow extension was the last movement; and S2, in which wrist flexion was the last movement. Final elbow and wrist joint angle and sensory response (SR) in five zones (Z1-Z5) were also registered. MR was qualitatively categorized as 'absent' (No-MR), 'true' (TMR) or 'uneven' (UMR). In both sequences, significant increases in muscle activity occurred mostly during shoulder abduction and elbow extension (p ≤ 0.009). Also, elbow extension but not wrist flexion increased the activity of the ECRB muscle (p ≤ 0.009). S2 showed significantly higher upper trapezius (p = 0.04) and biceps brachii (p = 0.036) muscle activity during wrist flexion, and higher report of SR in Z1 and Z4 (p < 0.001) compared to S1. Only the ECRB muscle showed significant differences in the MR type between S1 and S2 (TMR, p = 0.016; UMR, = 0,012). Our results may be useful in the assessment of upper limb musculoskeletal disorders.

Assessing muscle strength of persons with transfemoral amputation with and without a prosthesis: A cross-sectional study.

BACKGROUND: There is a gap in the research about the influence of wearing or not wearing a prosthesis for muscle strength assessment in transfemoral amputees (TFA) and how it is associated with functional mobility. OBJECTIVES: The aim of this study was to compare the muscle isometric strength of the residual limb with and without the prosthesis in people with TFA and to analyze associations between muscle strength and functional mobility. STUDY DESIGN: Cross-sectional study. METHODS: 20 subjects with TFA were included. A handheld dynamometer was used for the assessment of residual limb muscle strength. Functional mobility was assessed with the Timed Up and Go test. The Wilcoxon rank sum test with the rank biserial correlation effect size were used. RESULTS: There were statistically significant differences when testing isometric strength of the residual limb with and without the prosthesis (flexion [ p = 0.007], extension [ p < 0.001], and abduction [ p = 0.003]). There was association between functional mobility and flexion and abduction strength with the prosthesis ( p = 0.005, p = 0.01). CONCLUSIONS: Measurements of muscle strength of the residual limb were different when assessed with and without the prosthesis. Isometric strength of the residual limb in abduction and flexion using the prosthesis were correlated with functional mobility.

Personalized pain management: The relationship between clinical relevance and reliability of measurements.

Reliability is a topic in health science in which a critical appraisal of the magnitudes of the measurements is often left aside to favour a formulaic analysis. Furthermore, the relationship between clinical relevance and reliability of measurements is often overlooked. In this context, the aim of the present article is to provide an overview of the design and analysis of reliability studies, the interpretation of the reliability of measurements and its relationship to clinical significance in the context of pain research and management. The article is divided in two sections: the first section contains a step-by-step guide with simple and straightforward recommendations for the design and analysis of a reliability study, with a relevant example involving a commonly used assessment measure in pain research. The second section provides deeper insight about the interpretation of the results of a reliability study and the association between the reliability of measurements and their experimental and clinical relevance. SIGNIFICANCE: Reliability studies quantify the measurement error in experimental or clinical setups and should be interpreted as a continuous outcome. The assessment of measurement error is useful to design and interpret future experimental studies and clinical interventions. Reliability and clinical relevance are inextricably linked, as measurement error should be considered in the interpretation of minimal detectable change and minimal clinically important differences.

Effects of an exercise program plus manual therapy in a patient with failed neck surgery syndrome: A case report.

BACKGROUND: Patients who have undergone cervical surgery may present pain and dysfunction in the upper limb, which is often referred to as failed neck surgery syndrome. Little is known about the effects of an exercise program plus manual therapy in the treatment of prolonged neuropathic pain of the upper quadrant in a patient with failed neck surgery. CASE DESCRIPTION: A 66-year-old woman consulted for neuropathic pain and dysfunction during grasping activities, as a result of failed neck surgery after 12 months. Clinical, functional, and electromyographic measurements were recorded at baseline and after treatment. The patient underwent a treatment for six weeks based on manual therapy for the upper limb and cervical spine and an exercise program for the scapular muscles, rotator cuff and wrist extensor muscles. OUTCOMES: Positive clinically significant changes were observed in the Neuropathic Pain Questionnaire (DN4) (baseline = 7 points; post-treatment = 4 points), Neck Disability Index (NDI) (baseline = 36; post-treatment = 18 points), QuickDASH (baseline = 78; post- treatment = 32 points), Upper Limb Neurodynamic Test 1 (ULNT-1) (baseline = 75°; post- treatment = 42°) and grip strength (GS) (baseline = 23 kgf; post-treatment = to 32 kgf). Improvements in the surface electromyographic (sEMG) activity of the upper trapezius (UT), infraspinatus (IS) and radial wrist extensors (RWE) muscles also seemed to occur after treatment. CONCLUSION: Treatment helped relieve neuropathic pain, decrease neck disability, and improve general upper limb function.

No Evidence of Short-term Changes in Muscle Activity Elicited by Dry Needling in Chronic Unilateral Shoulder Pain Patients.

OBJECTIVE: The aim of the study was to assess short-term changes in shoulder muscle activity elicited by dry needling in chronic unilateral shoulder pain (USP) patients. METHODS: A randomized, double-blind, placebo-controlled clinical trial was conducted, in which 30 volunteers with USP were recruited and randomly assigned to either real or sham dry needling conditions. Pain intensity scores, pressure pain threshold, glenohumeral internal rotation angles, and electromyographic activity during isotonic shoulder tasks (shoulder flexion and extension) were assessed before, immediately, and 72 hours after the intervention in the infraspinatus and deltoid muscles. RESULTS: A single application of real dry needling resulted in lower pain intensity scores and a larger range in glenohumeral internal rotation 72 hours after the intervention in comparison with sham dry needling. No differences in pressure pain threshold or muscle activity were observed due to the intervention. DISCUSSION: A single application of real dry needling resulted in clinically significant changes in the short term. No differences were detected in muscle activation in the infraspinatus or deltoid muscles. Complementary interventions and longer follow-up times may be required to observe changes in muscle activity.

Dynamometric Strength Profile of Hip Muscles in Youth Soccer Players.

BACKGROUND: Soccer is the most widely practiced sport in the world, demanding high-speed activities such as jumps, sprints and changes of direction. Therefore, having optimal levels of muscle strength improves performance and reduces the injury rate. OBJECTIVES: The objectives of our study were (i) to determine the dynamometric profile of hip muscle strength in young soccer players by position, evaluated at different isokinetic speeds, (ii) to describe the conventional and functional unilateral muscle strength ratios, (iii) to analyze the bilateral balance. METHODS: Thirty-seven male soccer players (age 17.02 ± 0.92 years) participated in the study. Strength assessment was performed with a functional electromechanical dynamometer, and concentric and eccentric strength of abductors, adductors, extensors and hip flexors were measured bilaterally at 0.5 m/s and 1 m/s. RESULTS: For eccentric right hip abduction at 0.5 m/s, defenders are significantly stronger than midfielders (p = 0.013) and stronger than forwards (p = 0.140). For eccentric right hip adduction at 0.5 m/s, defenders are significantly stronger than midfielders (p = 0.005) and stronger than forwards (p = 0.253), as for eccentric right hip adduction at 1 m/s, defenders are significantly stronger than midfielders (p = 0.014) and stronger than forwards (p = 0.084). There is a significant effect for the conventional strength ratio of left abduction/adduction at 1 m/s. The conventional strength ratio of forwards is significantly higher than that of defenders (p = 0.045) and higher than that of midfielders (p = 0.152). CONCLUSIONS: Concentric and eccentric hip strength values differ according to playing position.

Effect of pain neuroscience education and transcutaneous electrical nerve stimulation on trigeminal postherpetic neuralgia. A case report.

INTRODUCTION: Postherpetic neuralgia (PHN) is a complex neuropathic painful condition in which pain is a direct consequence of the response to peripheral nerve damage experienced during herpes zoster attack. PHN is the most common chronic complication of herpes zoster and it causes considerable suffering, affecting the physical functioning and psychological well-being of patients. OBJECTIVE: To describe the effect of a conservative treatment using pain neuroscience education (PNE) and transcutaneous electrical nerve stimulation (TENS) in a patient with trigeminal PHN. CASE DESCRIPTION: A 67-year-old woman sought care for pain, dysfunction, and sensory loss in the left jaw. The assessment included: 1) pain, using the numerical pain rating scale (NPRS), pressure pain threshold (PPT), Douleur Neuropathique 4 (DN4), McGill Pain Questionnaire (MPQ), Graded Chronic Pain Scale (GCPS), and classic body charts of the cranial region; 2) somatosensory function, by means of mechanical detection threshold (MDT) and pressure pain threshold (PPT); 3) jaw function, using the Jaw Functional Limitation Scale-20 (JFLS-20); and 4) psychosocial features, by means of the Patient Health Questionnaire-9 (PHQ-9) and the Generalized Anxiety Disorders Questionnaire-7 (GAD-7). Treatment consisted of 12 sessions of PNE and TENS. OUTCOMES: After treatment, a clinically significant improvement in NPRS, DN4, MDT, GCPS, and PHQ-9 was observed. CONCLUSION: In this case report, a treatment based on the combination of PNE and TENS seemed to have contributed to improving pain, sensory abnormalities, and jaw function. Psychosocial factors also showed a trend to improve after the treatment.

Pressure pain threshold mappings of the infraspinatus muscle in chronic unilateral shoulder pain patients do not reflect generalized hypersensitivity.

OBJECTIVES: Increased mechanical sensitivity has been observed on the unaffected side in chronic pain conditions, suggesting generalized or widespread hypersensitivity. However, this cannot be considered as a universal response since this hypersensitivity is inconsistent across muscle pain pathologies. The aim of this study was to assess generalized hypersensitivity in chronic unilateral shoulder pain, using pressure pain threshold (PPT) mappings of the infraspinatus muscle. The proposed evaluation is based on the assessment of PPT on a limited subset of sites, reducing potential habituation or sensitization effects. METHODS: Twenty-nine patients with unilateral shoulder pain (USP) and twenty-seven healthy volunteers were recruited. PPT was assessed using a manual pressure algometer. Six sites distributed over the infraspinatus muscle were assessed, and three repetitions were performed at each site. Mappings were derived using two-dimensional interpolation. RESULTS: Lower PPT values were found in the symptomatic side in comparison with the asymptomatic side at all assessment sites (estimated difference: 1.42 ±â€¯0.10 kgf/cm2, p < 0.001), but there were no differences among the asymptomatic side of USP patients and any of the sides in healthy volunteers (largest estimated difference: 0.17 ±â€¯0.28 kgf/cm2, p = 0.927). Furthermore, the medial region of the infraspinatus muscle showed higher mechanical sensitivity in both healthy volunteers and USP patients. CONCLUSIONS: These results suggest that USP does not induce generalized hypersensitivity, in contrast with previously reported findings. Physiotherapists could take these results into account for the assessment and treatment of patients with USP.

Supine scapular punch: An exercise for early phases of shoulder rehabilitation?

BACKGROUND: Serratus anterior strengthening generally appears in shoulder rehabilitation protocols. This study's aim was to measure electromyographic activity of the serratus anterior, upper trapezius, and infraspinatus muscles during the Supine Scapular Punch exercise in healthy volunteers and those with unilateral shoulder pain. METHODS: Fifty-four participants were included and grouped as without (n = 34, age = 25.8 years) or with unilateral shoulder pain (n = 20, age = 26.3 years, visual analogue scale = 4.15 cm). Electromyographic activity of the serratus anterior, upper trapezius, and infraspinatus muscles was assessed during Supine Scapular Punch (four phases: P1 = press up concentric, P2 = Supine Scapular Punch concentric, P3 = Supine Scapular Punch eccentric, P4 = press up eccentric) performed under two conditions, with and without additional load. FINDINGS: Overall muscle activity during P1 and P4 was negligible (< 10% maximal voluntary isometric contractions). During P2 and P3, no statistically significant differences in serratus anterior and upper trapezius muscle activity were found between groups, with moderate to high serratus anterior activity (28.94% to 44.3%) and very low upper trapezius activity (< 6%). Upper trapezius/serratus anterior activity ratios ranged from 0.09 to 0.18. Overall infraspinatus muscle activity was always very low (< 10%). INTERPRETATION: The Supine Scapular Punch induces moderate to high serratus anterior muscle activity with very low upper trapezius and infraspinatus activation. Based on these results, the Supine Scapular Punch is a safe exercise that can be used in the early phases of shoulder rehabilitation.

Balance Differences between North and South American Older Adults: A Cross-Sectional, Age and Sex Matched Study.

This study aimed to characterize the risk of falling in low-, moderate- and high-risk participants from two different geographical locations using a portable force-plate. A sample of 390 older adults from South and North America were matched for age, sex, height and weight. All participants performed a standardized balance assessment using a force plate. Participants were classified in low, moderate and high risk of falling. No differences were observed between South and North American men, nor comparing North American men and women. South American women showed the significantly shorter center of pressure path length compared to other groups. The majority of the sample was categorized as having low risk of falling (male: 65.69% and female: 61.87%), with no differences between men and women. Moreover, no differences were found between North vs. South Americans, nor between male and female groups compared separately. In conclusion, South American women had better balance compatible with the status of the 50-59 years' normative age-range. The prevalence of low falls risk was~61-65%; the prevalence of moderate to high risk was~16-19%. The frequency of fall risk did not differ significantly between North and South Americans, nor between males and females.

Validity and Test-Retest Reliability of a Novel Push Low-Cost Hand-Held Dynamometer for Knee Strength Assessment during Different Force Ranges.

The objective was to assess the instrumental validity and the test-retest reliability of a low-cost hand-held push dynamometer adapted from a load-cell based hanging scale (tHHD) to collect compressive forces in different ranges of compressive forces. Three independent raters applied 50 pre-established compressions each on the tHHD centered on a force platform in three distinct ranges: ~70 N, ~160 N, ~250 N. Knee isometric strength was also assessed on 19 subjects in two sessions (48 h apart) using the tHHD anchored by an inelastic adjustable strap. Knee extension and flexion were assessed with the participant seated on a chair with the feet resting on the floor, knees, and hips flexed at 90°. The isometric force peaks were recorded and compared. The ICC and the Cronbach's α showed excellent consistency and agreement for both instrumental validity and test-retest reliability (range: 0.89-0.99), as the correlation and determination coefficients (range: 0.80-0.99). The SEM and the MDC analysis returned adequate low values with a coefficient of variation less than 5%. The Bland-Altman results showed consistency and high levels of agreement. The tHHD is a valid method to assess the knee isometric strength, showing portability, cost-effectiveness, and user-friendly interface to provide an effective form to assess the knee isometric strength.