Gisele Garcia Zanca

Functional torque ratios and torque curve analysis of shoulder rotations in overhead athletes with and without impingement symptoms

Abstract In this study, we evaluated the peak torque, functional torque ratios, and torque curve profile of the shoulder rotators in overhead athletes with impingement symptoms so as to examine possible alterations in response to sports training and shoulder pain. Twenty-one overhead athletes with impingement symptoms were compared with 25 overhead athletes and 21 non-athletes, none of whom were symptomatic for impingement. The participants performed five maximal isokinetic concentric and eccentric contractions of medial and lateral shoulder rotations at 1.57 rad · s−1 and 3.14 rad · s−1. Isokinetic peak torque was used to calculate the eccentric lateral rotation-to-concentric medial rotation and the eccentric medial rotation-to-concentric lateral rotation ratios. An analysis of the torque curve profiles was also carried out. The eccentric lateral rotation-to-concentric medial rotation torque ratio of asymptomatic athletes was lower than that of non-athletes at both test velocities. The concentric medial rotation isokinetic peak torque of the asymptomatic athletes, at 3.14 rad · s−1, was greater than that of the non-athletes, and the peak appeared to occur earlier in the movement for athletes than non-athletes. These findings suggest that there may be adaptations to shoulder function in response to throwing practice. The eccentric medial rotation-to-concentric lateral rotation torque ratio was altered neither by the practice of university-level overhead sports nor impingement symptoms.

Shoulder rotator strength and torque steadiness in athletes with anterior shoulder instability or SLAP lesion.

OBJECTIVES To investigate shoulder rotator strength and steadiness in athletes with anterior instability and superior labrum anterior posterior (SLAP) lesion. DESIGN Cross-sectional laboratory study. METHODS Athletes with anterior shoulder instability (instability group, n=10) and a SLAP lesion (SLAP group, n=10) were compared with healthy athletes matched by age, anthropometrics and sport (control group for shoulder instability, n=10 and control group for SLAP, n=10). Torque steadiness was evaluated with three 10s submaximal isometric contractions (35% of peak torque) with the arm at 90° of shoulder abduction and 90° of external rotation. The mean isometric torque, standard deviation and coefficient of variation were measured from the steadiness trials. To evaluate shoulder rotator strength, concentric isokinetic tests (90°/s, 180°/s) were performed at the 90-90° position and peak torque to body mass and shoulder external to internal rotation ratio variables were analyzed. The variables were tested with the instability and control groups with respect to shoulder instability and between the SLAP and control groups for SLAP lesion using the Mann-Whitney test. RESULTS The SLAP group presented a higher coefficient of variation than the SLAP control group (p=0.003). Regarding shoulder strength, the internal and external shoulder rotators were weaker in the instability group than in the instability control group (p<0.05). CONCLUSIONS Athletes with anterior shoulder instability presented shoulder rotation weakness, while athletes with a SLAP lesion showed higher torque fluctuation during internal rotation. These results indicate that there are different alterations to strength and sensory motor control in each condition.

Joint position sense is not altered during shoulder medial and lateral rotations in female assembly line workers with shoulder impingement syndrome

This study evaluated joint position sense (JPS) during medial and lateral rotations of the shoulder in female workers with and without shoulder impingement syndrome (SIS). Three groups were assessed. The case group consisted of 15 female assembly line workers (35.5, SD 5.8 years) with unilateral SIS. Control group 1 consisted of 15 female assembly line workers asymptomatic for SIS (34.4, SD 5.5 years) and control group 2 consisted of 15 female subjects (33.1, SD 6.2 years) asymptomatic for SIS and with no exposure to activities with the upper limbs. The JPS was evaluated bilaterally during passive (2°/sec) and active (5°/sec) repositioning tests using an isokinetic dynamometer. The target angles were 45° of lateral rotation (achieved by medially rotating the shoulder from 90° of lateral rotation) and 75° of lateral rotation (achieved by laterally rotating the shoulder from neutral rotation). There were no differences between sides for all groups (p  >  0.05). There were no differences in any of the variables between the case group and the control groups (p  >  0.05). The results of this study suggest that JPS during medial and lateral rotations of the shoulder is not altered in female assembly line workers with SIS.

Shoulder internal and external rotations torque steadiness in overhead athletes with and without impingement symptoms

OBJECTIVES This study aimed to investigate torque steadiness of shoulder internal and external rotations in regularly training overhead athletes with and without impingement symptoms. DESIGN Cross-sectional laboratory study. METHODS Three groups were evaluated: athletes with impingement symptoms (n=21), asymptomatic athletes (n=25) and non-athletes (n=21). To assess torque steadiness, the participants performed 3 submaximal contractions (35% of peak torque) for 10s each, with the arm at 90° of shoulder abduction and 90° of external rotation. The standard deviation, coefficient of variation, mean exerted torque and time to stability were measured from the steadiness trials. RESULTS The standard deviation of internal rotation was higher in asymptomatic athletes than in non-athletes (p<0.01); however, there was no difference between the athletes with impingement symptoms and the other groups. The other variables presented no differences among the groups. CONCLUSIONS Higher torque fluctuation of shoulder internal rotation in asymptomatic athletes may point to neuromuscular adaptations related to throwing training. However, the steadiness patterns of athletes with impingement symptoms did not differ from those of asymptomatic athletes or non-athletes.

Effects of Kinesio taping on scapular kinematics of overhead athletes following muscle fatigue.

Scapular kinematics alterations have been found following muscle fatigue. Considering the importance of the lower trapezius in coordinated scapular movement, this study aimed to investigate the effects of elastic taping (Kinesio taping, KT) for muscle facilitation on scapular kinematics of healthy overhead athletes following muscle fatigue. Twenty-eight athletes were evaluated in a crossover, single-blind, randomized design, in three sessions: control (no taping), KT (KT with tension) and sham (KT without tension). Scapular tridimensional kinematics and EMG of clavicular and acromial portions of upper trapezius, lower trapezius and serratus anterior were evaluated during arm elevation and lowering, before and after a fatigue protocol involving repetitive throwing. Median power frequency decline of serratus anterior was significantly lower in KT session compared to sham, possibly indicating lower muscle fatigue. However, the effects of muscle fatigue on scapular kinematics were not altered by taping conditions. Although significant changes were found in scapular kinematics following muscle fatigue, they were small and not considered relevant. It was concluded that healthy overhead athletes seem to present an adaptive mechanism that avoids the disruption of scapular movement pattern following muscle fatigue. Therefore, these athletes do not benefit from the use of KT to assist scapular movement under the conditions tested.

Kinesio taping of the deltoid does not reduce fatigue induced deficits in shoulder joint position sense

BACKGROUND Muscle fatigue is known to decrease shoulder proprioceptive acuity, potentially contributing to injuries. It has been suggested that Kinesio taping can improve proprioception. Therefore, the aim of this study was to investigate the effects of Kinesio taping on shoulder joint position sense after muscle fatigue. METHODS Twenty-four healthy subjects were evaluated in a randomized, crossover, single-blind study design. Shoulder joint position sense was assessed during active repositioning tests at the target angles of 50°, 70° and 90° of arm elevation in scapular plane, in three sessions: control (no taping), Kinesio taping (Kinesio taping applied over the deltoid muscle with tension) and sham (Kinesio taping applied over deltoid without tension). Joint position sense was assessed three times: before taping; following taping application or rest, in the control session; and following a fatigue protocol. The constant error (repositioned angle-target angle) was considered for statistical analysis, using a 3-way repeated-measure ANOVA (within subject factors: taping, time and target angle). FINDINGS There was no interaction or main effect involving taping. An interaction between time and angle was found and the simple effect showed that the constant error increased following fatigue at 70° and 90°, but not at 50°. INTERPRETATION The results of this study does not support the use of Kinesio taping applied over the deltoid muscle for compensating or preventing shoulder joint position sense deficits caused by muscle fatigue of shoulder abductors.

EMG of upper trapezius - Electrode sites and association with clavicular kinematics

The upper trapezius (UT) has been widely studied and related to alterations in clavicular kinematics in subject with shoulder disorders. However, the most common electrode site used to capture UT EMG is between C7 and the acromion, placing the electrodes over the acromial fibers rather than clavicular ones. Therefore, this study aimed to investigate the relationship between clavicular movements (elevation and retraction) and UT EMG recorded from three electrode sites (traditional electrode positioning and two different sites proposed for clavicular fibers evaluation). Furthermore, the position associated with the highest EMG during maximal isometric voluntary contractions (MVIC), for each electrode site, was determined for normalization purposes. EMG was simultaneously captured in the three electrode sites of 20 healthy subjects, during MVIC at five different positions and during shoulder elevation and abduction in scapular plane. Clavicular kinematics was recorded using an electromagnetic tracking system during the dynamic contractions. Shoulder abduction with head rotation and lateral flexion elicited the highest EMG amplitude on the three electrode sites and was used to normalize the signals. A cross-correlation analysis showed high correlations between all electrode sites and clavicular movements. However, the traditional electrode site seems to record more informative signals in healthy subjects.

Isokinetic dynamometry applied to shoulder rotators - velocity limitations in eccentric evaluations.

The objectives of this study were to evaluate if collegiate overhead athletes, with and without shoulder pain, and non-athletes could reach a preset velocity in internal and external shoulder rotation isokinetic evaluations; and to evaluate the correlation between torque and velocity. Controlled laboratory study, cross-sectional. Evaluations were performed using the isokinetic dynamometer Biodex System 3. Participants were assessed seated, with the arm at 90° of shoulder abduction and 90° of elbow flexion, from neutral rotation to 90° of external rotation. Five maximal contractions of isokinetic concentric and reactive eccentric internal and external rotation were performed at the velocities 90°/s, 180°/s and 240°/s. Data were processed with using MatLab. Most participants did not reach the isokinetic phase during eccentric tests at 180°/s and 240°/s, particularly in the external rotators evaluation. High correlations between torque and velocity of eccentric tests were found. The groups presented no differences in maximal velocity attained in trials which preset velocity was not reached. These results call into question the use of reactive eccentric tests at velocities higher than 180°/s for the isokinetic evaluation of shoulder external rotators in collegiate overhead athletes and non-athletes in this specific position. In such cases, careful evaluation of the velocity is recommended to determine if the isokinetic phase was reached.

Queixas musculoesqueléticas e procedimentos fisioterapêuticos na delegação brasileira paralímpica durante o mundial paralímpico de atletismo em 2011

Introduction: Athletics is an umbrella sport with high incidence of musculoskeletal injuries; however, the literature presents little information on injuries in Paralympics athletics. Objective: This study was to describe the profile of the musculoskeletal complaints, their anatomical locations, and physiotherapeutic resources used during the Paralympic Athletics World Championships in Christchurch in 2011. Methods: The Brazilian delegation included 34 athletes. Their musculoskeletal complaints, affected anatomical regions, and the physiotherapy resources used were daily recorded for all of the physiotherapy sessions. The sessions were held in the hotel that hosted the delegation and at the competition venue. Results: Out of the 34 athletes, 25 (73.5%) were treated at the Department of Physiotherapy. The main complaints were myalgia (38.4%), followed by arthralgia (23%). The region of the body with the most complaints was the thigh (n = 8, 30.7%), followed by the knee (n = 6, 23%). A total of 428 physiotherapy sessions were performed. At the hotel, the mostly used therapeutic approach was the ultrasound (35.1%), followed by TENS (31.2%) and cryotherapy (23.3%). At the competition venue, the mostly used therapeutic approach was cryotherapy (44.1%), followed by massage (37.2%). Conclusion: The results of this study contribute to a better understanding of the major injuries in this sport and help to develop programs aimed for injury prevention.

Isometric medial and lateral rotations torque steadiness in female workers with shoulder impingement

This study compared peak torque and torque steadiness during isometric lateral and medial rotations in workers with shoulder impingement syndrome (SIS) and those with no upper limb disorders. Twenty-nine female workers were evaluated. The SIS group consisted of 14 workers (36.57± 5.23 years) with unilateral SIS. The control group consisted of 15 healthy workers (35.53 ± 5.46 years). Three maximal voluntary isometric contractions (MVIC) of 5-s duration were performed to determine the peak torque, which was used to calculate the target torque (50% MVIC). For assessment of the torque steadiness 3 trials were performed at the target torque for 5 s each, with visual feedback. Standard deviation (SD) and coefficient of variati on (CV) were measured from the steadiness trials. Peak torque, SD and CV were not different (P > 0.05) between groups neither between affected and unaffected sides of the SIS group for both rotations. It was possible to suggest that torque steadin ess, during isometric medial and lateral rotations of the shoulder, is n ot altered in workers with SIS when compared to healthy workers, and that maintenance of regular work activities may play an important role in preservation of the steadiness in this populat ion.