vendex and Shoulder-Pain

To determine the effect of small daily amounts of progressive resistance training on rapid force development of painful neck/shoulder muscles.. 198 generally healthy adults with frequent neck/shoulder muscle pain (mean: age 43.1 years, computer use 93% of work time, 88% women, duration of pain 186 day during the previous year) were randomly allocated to 2- or 12 min of daily progressive resistance training with elastic tubing or to a control group receiving weekly information on general health. A blinded assessor took measures at baseline and at 10-week follow-up; participants performed maximal voluntary contractions at a static 90-degree shoulder joint angle. Rapid force development was determined as the rate of torque development and maximal muscle strength was determined as the peak torque.. Compared with the control group, rate of torque development increased 31.0 Nm s(-1) [95% confidence interval: (1.33-11.80)] in the 2-min group and 33.2 Nm s(-1) (1.66-12.33) in the 12-min group from baseline to 10-week follow-up, corresponding to an increase of 16.0% and 18.2% for the two groups, respectively. The increase was significantly different compared to controls (P<0.05) for both training groups. Maximal muscle strength increased only ~5-6% [mean and 95% confidence interval for 2- and 12-min groups to control, respectively: 2.5 Nm (0.05-0.73) and 2.2 Nm (0.01-0.70)]. No significant differences between the 2- and 12-min groups were evident. A weak but significant relationship existed between changes in rapid force development and pain (r = 0.27, P<0.01), but not between changes in maximal muscle strength and pain.. Small daily amounts of progressive resistance training in adults with frequent neck/shoulder pain increases rapid force development and, to a less extent, maximal force capacity.

Topics: Adult; Biomechanical Phenomena; Denmark; Female; Humans; Male; Muscle Contraction; Muscle Strength; Neck Muscles; Neck Pain; Pain Measurement; Resistance Training; Shoulder Pain; Time Factors; Torque; Treatment Outcome

This study compared core stability, shoulder isokinetic peak torque and shoulder function in throwers with and without shoulder pain.. Cross-sectional study.. Throwing athletes.. Thirty healthy athletes and 21 with shoulder pain were included.. Endurance time of the trunk, the modified star excursion balance test, isokinetic peak torque of internal and external rotation of the shoulder, questionnaires, level of satisfaction with the throwing arm and active range of motion.. The symptomatic athletes presented with shorter endurance time for the trunk lateral flexors (P < .05), and decreased reach distance for both limbs in the posteromedial direction (P < .05) and for takeoff limb in the posterolateral direction (P = .04), and smaller composite score for both limbs (P < .05) during star excursion balance test as compared to the healthy ones. No significant differences between groups were found for peak torque of internal and external rotation of the shoulder. Athletes with shoulder pain demonstrated more shoulder disability and a lower level of satisfaction with the throwing arm (P = .000). Range of motion was not different between groups for shoulder internal and external rotation.. Throwing athletes with shoulder pain have lower core stability and shoulder function compared to healthy athletes.

Topics: Adolescent; Adult; Athletes; Biomechanical Phenomena; Cross-Sectional Studies; Female; Humans; Male; Postural Balance; Range of Motion, Articular; Rotation; Shoulder; Shoulder Pain; Torque; Young Adult

To examine whether differences in propulsion technique as a function of intraindividual variability occur as a result of shoulder pain and physical activity (PA) level in full-time manual wheelchair users (MWUs).. Observational study.. Research laboratory.. Adults (N=14) with spinal cord injury (mean age: 30.64±11.08) who used a wheelchair for >80% of daily ambulation and were free of any condition that could be worsened by PA.. Not applicable.. PA level was measured using the Physical Activity Scale for Individuals with Physical Disabilities (PASIPD), and shoulder pain was measured using the Wheelchair User's Shoulder Pain Index (WUSPI) survey. Mean and intraindividual variability propulsion metrics were measured for propulsion analysis.. WUSPI scores indicated participants experienced low levels of shoulder pain. The results of the Spearman rank-order correlation revealed that PASIPD scores were significantly related to mean contact angle (r. Differences in propulsion technique were observed on the basis of PA levels. Participants with higher PASIPD scores used a more injurious stroke technique when propelling at higher speeds. This may indicate that active individuals who use injurious stroke mechanics may be at higher risk of injury. A strong relation was found between peak propulsion forces and shoulder pain. Rehabilitation professionals should emphasize the use of a protective stroke technique in both inactive and active MWUs during exercise and faster propulsion.

Topics: Adult; Biomechanical Phenomena; Exercise; Exercise Test; Female; Humans; Male; Middle Aged; Shoulder Pain; Spinal Cord Injuries; Torque; Wheelchairs; Young Adult

The aim of this study was to assess whether side-to-side differences in morphology and function of the upper limbs in 11-12 year-old male baseball players with throwing-related pain (n=14) were more pronounced than that of age-matched healthy untrained subjects (n=16). Baseball players 1) had played baseball≥4.5 h·wk

Topics: Baseball; Case-Control Studies; Child; Elbow Injuries; Elbow Joint; Humans; Male; Muscle Strength; Muscle Strength Dynamometer; Pain; Pain Measurement; Range of Motion, Articular; Shoulder Injuries; Shoulder Joint; Shoulder Pain; Surveys and Questionnaires; Torque

Shoulder joint pain is a frequent secondary complaint for people following spinal cord injury (SCI).. The purpose of this study was to determine predictors of shoulder joint pain in people with paraplegia.. A 3-year longitudinal study was conducted. Participants were people with paraplegia who used a manual wheelchair for at least 50% of their mobility and were asymptomatic for shoulder pain at study entry. Participants were classified as having developed shoulder pain if they experienced an increase of ≥10 points on the Wheelchair User's Shoulder Pain Index in the 3-year follow-up period. Measurements of maximal isometric shoulder torques were collected at study entry (baseline), 18 months, and 3 years. Daily activity was measured using a wheelchair odometer, and self-reported daily transfer and raise frequency data were collected by telephone every 6 weeks.. Two hundred twenty-three participants were enrolled in the study; 39.8% developed shoulder pain over the 3-year follow-up period. Demographic variables and higher activity levels were not associated with shoulder pain onset. Baseline maximal isometric torque (normalized by body weight) in all shoulder muscle groups was 10% to 15% lower in participants who developed shoulder pain compared with those who remained pain-free. Lower shoulder adduction torque was a significant predictor of shoulder pain development (log-likelihood test=11.38), but the model explained only 7.5% of shoulder pain onset and consequently is of limited clinical utility.. Time since SCI varied widely among participants, and transfer and raise activity was measured by participant recall.. Participants who developed shoulder pain had decreased muscle strength, particularly in the shoulder adductors, and lower levels of physical activity prior to the onset of shoulder pain. Neither factor was a strong predictor of shoulder pain onset.

Topics: Adult; Cohort Studies; Female; Humans; Male; Motor Activity; Muscle Strength; Muscle, Skeletal; Paraplegia; Risk Factors; Shoulder Pain; Spinal Cord Injuries; Torque; Weight-Bearing; Wheelchairs

The main goal of this prospective study was to identify the most significant intrinsic risk factors for shoulder pain by measuring strength developed by shoulder rotators and by carrying out various morphostatic assessments.. Sixty-six players (mean ± SD age = 24 ± 5 yr) were recruited from nine volleyball teams from the first and second divisions (34 men and 32 women) to participate in the study. Before the start of the volleyball season, all the participants completed a preseason questionnaire and underwent both a bilateral isokinetic evaluation of the shoulders and morphostatic measurements. During the subsequent 6 months of the competition period, the players reported through a weekly questionnaire any shoulder pain experienced.. During the ongoing season, 23% (15 of 66 players) of the volleyball players experienced dominant shoulder pain. Interestingly, participants who reported a history of dominant shoulder pain were found to have nine times higher risk of suffering further pain in their dominant shoulder. The eccentric maximal strength developed by the internal and external rotators was found to represent a protective factor in the volleyball players (respective odds ratios = 0.946, P = 0.01 and 0.94, P = 0.05). No risk factors were found among the shoulder morphostatic measurements.. In our study, the evaluation of shoulder rotator muscle strength through isokinetic assessment, especially eccentric mode, appeared to be the most contributing parameter to identify risk factors for shoulder pain. This evaluation should allow to better identify players at risk.

Topics: Adult; Female; Humans; Male; Muscle Contraction; Muscle Strength; Muscle, Skeletal; Prospective Studies; Range of Motion, Articular; Recurrence; Risk Factors; Rotation; Shoulder; Shoulder Joint; Shoulder Pain; Surveys and Questionnaires; Torque; Volleyball; Young Adult

The incidence of (a)symptomatic rotator cuff tears is high, but etiologic mechanisms are unclear and treatment outcomes vary. A practical tool providing objective outcome measures and insight into etiology and potential patient subgroups is desirable. Symptomatic cuff tears coincide with humerus cranialization. Adductor co-activation during active arm abduction has been reported to reduce subacromial narrowing and pain in cuff patients. We present an easy-to-use method to evaluate adductor co-activation. Twenty healthy controls and twenty full-thickness cuff tear patients exerted EMG-recorded isometric arm abduction and adduction tasks. Ab- and adductor EMG's were expressed using the "Activation Ratio (AR)" (-1 ≤ AR ≤ 1), where lower values express more co-activation. Mean control AR's ranged from .7 to .9 with moderate to good test-retest reliability (ICC: .60-.74). Patients showed significantly more adductor co-activation during abduction, with adductor AR's ranging between .3 (teres major) and .5 (latissimus dorsi). In conclusion, the introduced method discriminates symptomatic cuff tear patients from healthy controls, quantifies adductor co-activation in an interpretable measure, and provides the opportunity to study correlations between muscle activation and humerus cranialization in a straightforward manner. It has potential as an objective outcome measure, for distinguishing symptomatic from asymptomatic cuff tears and as a tool for surgical or therapeutic decision-making.

Topics: Adult; Arthrography; Biomechanical Phenomena; Computer Simulation; Electromyography; Female; Humans; Image Processing, Computer-Assisted; Isometric Contraction; Magnetic Resonance Imaging; Male; Middle Aged; Models, Anatomic; Muscle, Skeletal; Orientation; Range of Motion, Articular; Reference Values; Rotator Cuff; Rotator Cuff Injuries; Shoulder Impingement Syndrome; Shoulder Joint; Shoulder Pain; Signal Processing, Computer-Assisted; Torque; Young Adult

Peak torque (PT), total work (TW) and acceleration time (AT) were measured during isokinetic concentric and eccentric abduction of the shoulder in subjects with subacromial impingement syndrome (SIS) and healthy subjects. The SIS group consisted of 27 subjects (33.48 +/- 9.94 years) with unilateral SIS and it was divided into two groups: (1) SIS with the dominant involved side, (2) SIS with the nondominant involved side. The control group consisted of 23 healthy subjects (32.26 +/- 9.04 years). PT, TW and AT were measured bilaterally at 60 and 180 degrees /s. No significant interactions were found between group and side (P > 0.05), as well as no significant main effects of group and side (P > 0.05) for all variables during concentric abduction of the shoulder at both tested speeds. During the eccentric contractions, lower TW (P < 0.05) was demonstrated by the nondominant uninvolved side of SIS group at 60 degrees /s, and by the uninvolved sides of the SIS groups at 180 degrees /s compared to the dominant side of the controls. At 180 degrees /s, the nondominant uninvolved side of the SIS group demonstrated slower AT (P < 0.05) compared to the dominant side of the control group, as well as the nondominant involved side of the SIS group compared to the nondominant side of the controls. The results showed no alterations in the measured parameters during concentric and eccentric phases of isokinetic abduction in subjects with SIS when compared to a control group. However, alterations may be observed in the contralateral side during the eccentric phase of abduction in subjects with unilateral conditions of SIS.

Topics: Adult; Biomechanical Phenomena; Case-Control Studies; Disability Evaluation; Female; Functional Laterality; Humans; Male; Muscle Contraction; Muscle Strength; Pain Measurement; Rotator Cuff; Shoulder Impingement Syndrome; Shoulder Joint; Shoulder Pain; Surveys and Questionnaires; Time Factors; Torque

We previously demonstrated that the steadiness of shoulder abduction is reduced in patients with subacromial impingement syndrome (SIS), which might be related to shoulder pain associated with the SIS. The aim of the present study was to examine the acute effects of experimental shoulder muscle pain on shoulder motor function in healthy subjects. The fluctuations in exerted force (force steadiness) and electromyographic (EMG) activity from eight shoulder muscles were determined during sub-maximal isometric and dynamic contractions with the shoulder abductors in nine healthy subjects (27.7 +/- 4.2 years, mean +/- 1 SD) before, during and after experimental pain induction. Experimental pain was induced by bolus injections of 6% hypertonic saline into the supraspinatus muscle. Experimental muscle pain reduced shoulder-abduction force steadiness on average by 21% during isometric contractions (P = 0.012) and tended to do so during concentric contractions (P = 0.083). Middle deltoid, and infraspinatus and lower trapezius muscle activity increased (3-5% EMG(max)) during isometric and concentric contractions, respectively (P < 0.05). Thus, experimental shoulder muscle pain reduced the steadiness of isometric shoulder abduction and caused small changes in the abduction activation strategy. The observed effects of experimental pain on shoulder motor function differed from that observed previously in patients with SIS and chronic pain during the same types of contractions. A possible explanation may be that, even though the adopted experimental pain-paradigm may reflect the SIS in terms of the painful structures, it might not reflect the adaptations in the central nervous system seen with chronic pain.

Topics: Adult; Electromyography; Humans; Injections, Intramuscular; Motor Activity; Muscle Contraction; Muscle, Skeletal; Pain Measurement; Rotator Cuff; Saline Solution, Hypertonic; Shoulder Impingement Syndrome; Shoulder Pain; Torque

Previous investigations have identified muscular imbalance in the shoulder as a source of pain and injury in manual wheelchair users. Our aim was to determine whether a correlation exists between strength and pushrim biomechanical variables including: tangential (motive) force (Ft), radial force (Fr), axial force (Fz), total (resultant) force (FR), fraction of effective force (FEF), and cadence.. Peak isokinetic shoulder strength (flexion [FLX], extension [EXT], abduction [ABD], adduction [ADD], internal rotation [IR], and external rotation [ER]) was tested in 22 manual wheelchair users with a BioDex system for 5 repetitions at 60 degrees/s. Subjects then propelled their own manual wheelchair at 2 speeds, 0.9 m/s (2 mph) and 1.8 m/s (4 mph), for 20 seconds, during which kinematic (OPTOTRAK) and kinetic (SMARTWHEEL) data were collected. Peak isokinetic forces in the cardinal planes were correlated with pushrim biomechanical variables.. All peak torque strength variables correlated significantly (P < or = 0.05) with Ft, Fr, and FR, but were not significantly correlated with Fz, FEF, or cadence. Finally, there were no relationships found between muscle strength ratios (for example, FLX/EXT) and Ft, Fr, FR, Fz, or FEF.. There was a correlation between strength and force imparted to the pushrim among wheelchair users; however, there was no correlation found in wheelchair propulsion or muscle imbalance. Clinicians should be aware of this, and approach strength training and training in wheelchair propulsion techniques separately.

Topics: Adult; Biomechanical Phenomena; Data Interpretation, Statistical; Female; Humans; Male; Middle Aged; Muscle, Skeletal; Shoulder; Shoulder Pain; Spinal Cord Injuries; Torque; Wheelchairs

This cross-sectional study aimed at investigating the influence of occupational exposure to static and highly repetitive work involving the neck and shoulder muscles, myalgia of and tender point in the trapezius muscle on biomechanical output, and electromyogram (EMG) variables (mean frequency MNF, signal amplitude and ability to relax) during maximal forward flexions of the shoulder muscles. Groups of 25 cleaners suffering from chronic myalgia of the trapezius muscle, 25 cleaners free from myalgia of the trapezius muscle and 21 teachers performed 150 forward flexions using an isokinetic dynamometer. Perception of fatigue was reported and surface EMG was recorded from four muscles during the endurance test. The cleaners were stronger than the teachers. Myalgia was associated with lower levels of endurance and a high degree of perceived fatigue. The ability to relax the trapezius muscle decreased with age and was even lower in cleaners with and without myalgia. Higher MNF of the deltoid muscle but not of the trapezius muscle was found in the group suffering from myalgia compared to the groups free from myalgia. This cross-sectional study indicated that myalgia of the trapezius muscle did not influence the strength but did influence the endurance of the forward flexor muscles of cleaners. The observed decrease in the ability to relax the trapezius muscle in cleaners compared to healthy teachers might be indicative of a future insufficiency in the muscle. Prospective studies are needed to define the significance of the results presented here.

Topics: Cross-Sectional Studies; Electromyography; Exercise Test; Female; Humans; Middle Aged; Muscle Fatigue; Muscle Relaxation; Muscle, Skeletal; Occupational Diseases; Perception; Physical Endurance; Shoulder; Shoulder Pain; Torque