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Latissimus dorsi may contribute to trunk movement and control because of its extensive attachments to the trunk. However, electromyography studies have shown highly variable activity levels during trunk tasks. To critically evaluate whether latissimus dorsi has a role in trunk movement and/or control. Studies assessing the activation of latissimus dorsi using electromyography during trunk movements and/or trunk stability tasks were sourced (May 2022). Risk of biases and quality of evidence was assessed. Activation levels were pooled and meta-analysed where possible. Thirty nine of 6125 studies identified in the search met the inclusion criteria. The meta-analyses showed high latissimus dorsi activity levels (60% maximal voluntary contraction [MVC]) during ipsilateral trunk rotation and low levels (<20% MVC) during contralateral trunk rotation, extension and stability tasks. Considerable variability of activity levels existed between studies when using high loads. Quality of evidence was very low to moderate. Although high activity levels were found during ipsilateral trunk rotation, there is very low confidence that these activity levels reflect the true levels. There is moderate confidence latissimus dorsi has a limited contribution to trunk control. The use of surface electrodes and non-validated normalisation processes were critical methodological issues that contributed to lower quality of evidence. [ABSTRACT FROM AUTHOR]

Context: Shoulder muscle activation in patients with subacromial impingement is highly cited and variable in the literature. Differences between studies could be due to artifacts introduced by normalization practices in the presence of pain. Ultimately, this lack of knowledge pertaining to pathogenesis limits the clinical treatment and restoration of muscular function. Design: A total of 21 patients with stage 2 subacromial impingement and 21 matched controls were recruited for EMG testing of their affected shoulder during an arm elevation task. The patients were tested before and after receiving an injection to their subacromial bursa. Methods: The EMG from 7 shoulder muscles were measured before and after treatment during humeral motion in the scapular plane. Results: Our findings indicate an increase in anterior deltoid, middle deltoid, and upper trapezius activity following the injection; further, this trend extended to the controls. The control subjects had a greater activation of the latissimus dorsi at peak arm elevation when compared with the patient group postinjection. Conclusions: Our results indicate that a reduction in subacromial pain is associated with changes in shoulder muscle recruitment, primarily of the deltoid. This change in deltoid activity may lend evidence to rotator cuff function in patients without rotator cuff tears. [ABSTRACT FROM AUTHOR]

Introduction: Intermuscular implantations of subcutaneous implantable cardioverter‐defibrillators (S‐ICD) have been recommended, but the position of the anterior border of the latissimus dorsi muscle (LDM) has not previously been evaluated in establishing an incision line to facilitate the intermuscular approach. The objective of this study is to evalua the position and trend of the anterior border of the LDM in patients who are candidates for implantable cardioverter‐defibrillators. Methods: The distance from the back to the anterior border of the LDM (A) and the anterior–posterior width of the chest wall (B) were measured on computed tomography retrospectively, and the ratio (=A/B) was used as the position of the anterior border of the LDM. In addition, the variability and factors affecting the values were evaluated. Results: An analysis was performed on 78 patients, and the position of the anterior border of the LDM (=A/B) exhibited a normal distribution, with a mean value of 0.53 ± 0.062 (0.41–0.69). The position of the anterior border of the LDM tended to be more anterior in younger, taller, male, primary prevention, nonheart failure, low brain natriuretic peptide level, and nondiabetic patients. Conclusion: The position of the anterior border of the LDM varied from case to case with variable results. Conventional incisions on the midaxillary line may be inappropriate for intermuscular implantations, and the position of the anterior border of the LDM should be evaluated in each individual case to establish the incision line. [ABSTRACT FROM AUTHOR]

Context: The latissimus dorsi plays a major role in generating the propulsive force during swimming. In addition, stiffness of this muscle may result in altered stroke biomechanics and predispose swimmers to shoulder pain. Measuring the flexibility of the latissimus dorsi can be of interest to reduce injury. However, the reliability of such measurement has not yet been investigated in competitive swimmers. Objective: To assess the within-session intrarater and interrater reliability of a passive shoulder flexion range of motion measurement for latissimus dorsi flexibility in competitive swimmers. Design: Within-session intrarater and interrater reliability. Setting: Competitive swimming clubs in Flanders, Belgium. Participants: Twenty-six competitive swimmers (15.46 [2.98] y; 16 men and 10 women). Intervention: Each rater performed 2 alternating (eg, left-right-left-right) measurements of passive shoulder flexion range of motion twice, with a 30-second rest period in between. Main Outcome Measures: The intraclass correlation coefficients were calculated to assess intrarater and interrater reliability. Results: Interrater intraclass correlation coefficient ranged from.54 (95% confidence interval [CI], −.16 to.81) to.57 (95% CI, −.24 to.85). Results for the intrarater reliability ranged from.91 (95% CI,.81 to.96) to.94 (95% CI,.87 to.97). Conclusion: Results of this study suggest that shoulder flexion range of motion in young competitive swimmers can be measured reliably by a single rater within the same session. [ABSTRACT FROM AUTHOR]

Purpose: There is controversy regarding the optimal treatment for patients with rotator cuff arthropathy with external rotation deficit (CLEER group). This study analyzes the biomechanical and electromyographical outcomes of reverse total shoulder arthroplasty (RTSA) with latissimus dorsi and teres major transfer. The primary objective of this study is to compare the biomechanical and electromyographical outcomes between the treated and contralateral shoulder. Secondary objective is to define clinical and functional outcomes, and to report the radiological findings. Our hypothesis is that with this technique patients regain at least 50% of the strength in external rotation of the contralateral shoulder, and that the transferred muscles remain EMG active over time. Materials and methods: All patients who underwent RTSA with latissimus dorsi and teres major transfer in our hospital between 2007 and 2015 were included. From 16 eligible patients, 10 were finally reviewed. Biomechanical assessment of rotation strength was performed postoperatively in both shoulders, and fine needle EMG of latissimus dorsi and teres major muscles was recorded at the same time in both shoulders. Constant test and clinical evaluation (Lag sign and Hornblower test) were obtained preoperative and at final follow up. Radiological (X-ray, US) assessment was also obtained for both shoulders at final follow up. Results: External rotation strength of the operated shoulder was higher than 50% the strength of the contralateral shoulder, and the differences were statistically significant (p < 0.05). No statistically differences were found regarding to internal rotation. The electromyographic assessment found no significant differences (p > 0.05) between the treated and contralateral shoulders. The mean Constant-Murley score significantly increased (30.9 points) after surgery (p < 0.01). Lag sign and Hornblower test were negative in all patients. Conclusions: Performing RTSA with latissimus dorsi and teres major transfer is an effective procedure improve function and to restore ER strength in patients in CLEER group. The EMG records shows that transposed latissimus dorsi and teres major adapt to their new function and remain functional over time, even in elderly patients. [ABSTRACT FROM AUTHOR]

Background: The effect of load distribution applied to the trunk musculature with lunge exercises has yet to be determined. The aim of this study was to evaluate the effect of load placement using dumbbells on the activation of the latissimus dorsi, erector spinae, external oblique, and rectus abdominis muscles during the lunge. Methods: Forty-two amateur athletes (21 men and 21 women) were recruited. Three lunge exercises were performed with different loading arrangements (ipsilateral, contralateral, and bilateral). The principal variable recorded for muscle activity was mean "root mean square" expressed as the percentage of the maximal voluntary isometric contraction. Results: There are statistically significant differences in the erector spinae (p < 0.001; p < 0.003) and external oblique muscles (p < 0.009; p < 0.001) compared with the contralateral side. The muscle on the opposite side of the load achieved higher activation for these muscles. The erector spinae and latissimus dorsi muscle did not reach a statistically significant difference with the contralateral side in any exercise (p > 0.05). The higher activation of the latissimus dorsi occurred on the same side on which the load was placed. Conclusions: There was higher activation of the erector spinae, external oblique, and rectus abdominis muscles contralateral to the side of load placement during lunge exercise by amateur athletes. [ABSTRACT FROM AUTHOR]

Objective. To measure the surface electromyographic (EMG) activity of gluteus maximus (GMax) and latissimus dorsi (LD) muscles during walking and to measure the scapular upward rotation at different ranges of shoulder abduction in subjects with chronic nonspecific low back pain (CNSLBP) versus healthy controls. Methods. Twenty-six subjects with unilateral CNSLBP with a mean age (y) of 25.15 ± 4.11 and 26 age-matched healthy controls with mean age (y) of 23.88 ± 2.64 were recruited through direct referrals for this cross-sectional, comparative analysis. EMG activity of the GMax and contralateral LD muscles were recorded during treadmill walking using surface electrodes. Scapular upward rotation was measured using bubble inclinometers at 0°, 45°, 90°, 135°, and end range abduction. Analysis of variance (ANOVA) was used to analyze the difference between the two groups. Results. No statistically significant difference existed between the two groups regarding the recorded EMG activity of GMax and LD muscles during walking. Also, there was no statistically significant difference between the groups in scapular upward rotation measured at the different ranges of shoulder abduction. Conclusions. EMG activity of GMax and LD muscles and scapular upward rotation does not seem to be different between subjects with CNSLBP and healthy controls. [ABSTRACT FROM AUTHOR]

BACKGROUND: Sacroiliac Joint Dysfunction (SIJD) may be observed in 13% to 30% people with idiopathic low back pain (LBP). Latissimus dorsi (LD) muscle works by stabilizing the SIJ, providing a pathway for force transmission through the thoraco lumbar fascia. Literature has shown that muscles can change their activation pattern in response to pain, altering motor control. However, to date, there have been no studies evaluating the EMG activity of LD in people with SIJD while lifting a load, this could guide for a better understanding about how muscle activation occurs in this group of patients. AIM: To evaluate and compare activation of LD in people with LBP, SIJD and without LBP in load lifting. METHODS: One hundred fourteen people were evaluated and divided into 3 groups: LBP, SIJD and Control group. EMG signals were recorded from LD while the subjects lifted a load in a symmetrical posture. Subjects started in an upright position, grasped the box from the floor and returned to the initial position with flexed elbows. Root Mean Square (RMS) amplitude and latency were calculated. The Kruskal-Wallis and the post hoc Dunn's tests were used to compare groups. RESULTS: Results showed that left LD in SIJD group is activated 26.21% more than in the control group and 23.98% than the LBP group (p = 0.02). Besides, right LD has a delayed onset in SIJD by 0.68 ms compare with the control group and 0.29 ms with LBP group (p = 0.03). CONCLUSION: In a specific group of individuals with SIJD, alterations in LD muscle activation, could be evidenced by an increased RMS amplitude which is accompanied with a delay in activation in the opposite side during lifting a load in a symmetrical posture. [ABSTRACT FROM AUTHOR]

Purpose: To characterize the relationships between muscle oxygenation and performance during on- and off-water tests in highly trained sprint canoe–kayak athletes. Methods: A total of 30 athletes (19 kayakers and 11 canoeists) performed a maximal incremental test on a canoe or kayak ergometer for determination of VO2max and examination of the relation between peak power output (PPO) and physiological parameters. A subset of 21 athletes also performed a 200- and a 500- (for women) or 1000-m (for men) on-water time trial (TT). Near-infrared spectroscopy monitors were placed on the latissimus dorsi, biceps brachii, and vastus lateralis during all tests to assess changes in muscle O2 saturation (SmO2) and deoxyhemoglobin concentration ([HHb]). The minimum O2 oxygenation (SmO2min) and maximal O2 (Δ[HHb] extraction) were calculated for all subjects. Results: PPO was most strongly correlated with VO2max (R =.9), but there was also a large correlation between PPO and both SmO2min and Δ[HHb] in latissimus dorsi (R = −.5, R =.6) and vastus lateralis (R = −.6, R =.6, all P <.05). Multiple regression showed that 90% of the variance in 200-m performance was explained by both Δ[HHb] and SmO2min in the 3 muscles combined (P <.01) and 71% of the variance in 500-/1000-m performance was explained by Δ[HHb] in the 3 muscles (P <.01). This suggests that O2 extraction is a better predictor of performance than VO2max in sprint canoe–kayak. Conclusions: These results highlight the importance of peripheral adaptations in both short and long events and stress the relevance of adding muscle oxygenation measurements during testing and racing in sprint canoe–kayak. [ABSTRACT FROM AUTHOR]

Purpose. Posterior layer of thoracolumbar fascia (PTLF) is the part of the deep fascia of back of the trunk which connects the trunk, upper and lower limb muscles. PTLF is the major myofascial linkage where myofascial force transmission can take place between the muscles attached to it. The present study evaluates the force transmission through PTLF to the right and left latissimus dorsi, and right and left lower trapezius muscles during isometric contraction of right and left gluteus maximus. Materials and methods. Present descriptive observational study was conducted on 40 male adult healthy volunteers aged between 30 to 45 years. The Root mean square (RMS) value of EMG signal of the bilateral gluteus maximus, latissimus dorsi and lower trapezius muscles was collected using surface Electromyographic sensors. The Electromyographic assessment was carried out at normal contraction, at minimum resistance (load of 1 kg) and at maximum voluntary contraction with resistance (2-5.5 kg) of gluteus maximus. Results. When left gluteus maximus contracts normally (without any resistance), the mean RMS value was found to be 16.28 ± 3.15 µV and on maximum voluntary contraction (MVC) with resistance it was 28.95 ± 4.89 µV. When right gluteus maximus contracts normally without any resistance, the mean RMS value was found to be 25.83 ± 4.48 µV and MVC with resistance was 43.70 ± 2.60 µV. This showed around 30-70% increase in RMS value from normal contraction to MVC with resistance. The relative activation at different isometric contractions of right and left gluteal muscles were compared to the right and left latissimus dorsi and right and left lower trapezius muscles. A significant (p < 0.001) Pearson's correlation was observed between the muscles. Conclusions. Epimuscular myofascial force is transferred from the gluteus maximus muscles to other muscles attached to PTLF directly or indirectly to the same side as well as to the opposite side. The connection via PTLF to the muscles attached to it may affect the sensory feedback and thereby the neuromuscular control. In pathological conditions, same myofascial linkage may contribute to altered biomechanics of the back of the trunk. [ABSTRACT FROM AUTHOR]

BACKGROUND: A prerequisite for interpreting electromyography (EMG) data is to normalize them to a maximum voluntary contraction (MVC), expressing them as percentage of the MVC. OBJECTIVE: The objective of this study was to compare different recommended MVC exercises for the latissimus dorsi and identify the exercise that elicits the highest EMG amplitude. METHODS: Fifteen male participants were recruited. Five recommended MVC exercises were investigated, including chest-supported shoulder extension, prone shoulder extension, lat-pull down, abducted shoulder flexion, and internal shoulder rotation. RESULTS: Chest-supported shoulder extension reported the highest mean EMG, which was not significantly different from the mean EMG of prone shoulder extension. Both of these exercises led to significantly greater EMG means than the other exercises. Sixty percent of the participants achieved their highest EMG amplitude with chest-supported shoulder extension and 40% with prone shoulder extension. None of the other exercises elicited the highest EMG amplitude in any of the participants. CONCLUSIONS: Both chest-supported shoulder extension and prone shoulder extension proved to be effective MVC exercises, with the former showing more consistency in eliciting the highest EMG amplitude. If the true MVC is desired, the authors recommend performing both exercises and then using the overall highest EMG amplitude for normalization purposes. [ABSTRACT FROM AUTHOR]

The objective of the study was to investigate the effects of using lifting straps on the lat pull-down exercise on maximal strength, number of repetitions, and muscle activation. Twelve resistance-trained men participated (age 27 ± 4 years, body mass 84 ± 10 kg, height 177 ± 6 cm, resistance training experience 6.6 ± 2.4 years). All participants performed the 1RM tests and training protocols either with the lifting straps (WS) or without (WOS). Exercise sessions for both conditions (WS and WOS) consisted of 3 sets to concentric failure with a load of 70% of one repetition maximum (1RM) and rest intervals of 60 s. For the 1RM test, no difference was observed between WS and WOS conditions (96.5 ± 12.7 kg and 96.6 ± 11.9 kg, respectively). There were no differences between the WS and WOS conditions in the number of repetitions per set, total repetitions and latissimus dorsi muscle activation. In conclusion, the findings of this study demonstrate that the use of lifting straps in the lat pull-down exercise by resistance-trained individuals does not promote beneficial effect in the 1RM value, the number of repetitions performed with 70% of 1RM, and muscle activation. [ABSTRACT FROM AUTHOR]

This study aimed to profile the physiological characteristics of junior sprint kayak athletes (n = 21, VO2max 4.1 ± 0.7 L/min, training experience 2.7 ± 1.2 y) and to establish the relationship between physiological variables (VO2max, VO2 kinetics, muscleoxygen kinetics, paddling efficiency) and sprint kayak performance. VO2max, power at VO2max, power:weight ratio, paddling efficiency, VO2 at lactate threshold, and whole-body and muscle oxygen kinetics were determined on a kayak ergometer in the laboratory. Separately, on-water time trials (TT) were completed over 200 m and 1000 m. Large to nearly perfect (-.5 to -.9) inverse relationships were found between the physiological variables and on-water TT performance across both distances. Paddling efficiency and lactate threshold shared moderate to very large correlations (-.4 to -.7) with 200- and 1000-m performance. In addition, trivial to large correlations (-.11 to -.5) were observed between muscle-oxygenation parameters, muscle and whole-body oxygen kinetics, and performance. Multiple regression showed that 88% of the unadjusted variance for the 200-m TT performance was explained by VO2max, peripheral muscle deoxygenation, and maximal aerobic power (P < .001), whereas 85% of the unadjusted variance in 1000-m TT performance was explained by VO2max and deoxyhemoglobin (P < .001). The current findings show that well-trained junior sprint kayak athletes possess a high level of relative aerobic fitness and highlight the importance of the peripheral muscle metabolism for sprint kayak performance, particularly in 200-m races, where finalists and nonfinalists are separated by very small margins. Such data highlight the relative aerobic-fitness variables that can be used as benchmarks for talent-identification programs or monitoring longitudinal athlete development. However, such approaches need further investigation. [ABSTRACT FROM AUTHOR]

PURPOSE: To quantify the effects of a 12-wk isolated core-training program on 50-m front-crawl swim time and measures of core musculature functionally relevant to swimming. METHODS: Twenty national-level junior swimmers (10 male and 10 female, 16 ± 1 y, 171 ± 5 cm, 63 ± 4 kg) participated in the study. Group allocation (intervention [n = 10], control [n = 10]) was based on 2 preexisting swim-training groups who were part of the same swimming club but trained in different groups. The intervention group completed the core training, incorporating exercises targeting the lumbopelvic complex and upper region extending to the scapula, 3 times/wk for 12 wk. While the training was performed in addition to the normal pool-based swimming program, the control group maintained their usual pool-based swimming program. The authors made probabilistic magnitude-based inferences about the effect of the core training on 50-m swim time and functionally relevant measures of core function. RESULTS: Compared with the control group, the core-training intervention group had a possibly large beneficial effect on 50-m swim time (-2.0%; 90% confidence interval -3.8 to -0.2%). Moreover, it showed small to moderate improvements on a timed prone-bridge test (9.0%; 2.1-16.4%) and asymmetric straight-arm pull-down test (23.1%; 13.7-33.4%), and there were moderate to large increases in peak EMG activity of core musculature during isolated tests of maximal voluntary contraction. CONCLUSION: This is the first study to demonstrate a clear beneficial effect of isolated core training on 50-m front-crawl swim performance. [ABSTRACT FROM AUTHOR]

The primary aims of the study were to (a) quantify the effect of load magnitude on lumbopelvic-hip complex (LPHC) and scapular muscle activation and (b) quantify the effect of different carry positions on bilateral glutei medii (GM) and external oblique (EO) activation during unilateral dumbbell carries. Eighteen resistance-trained individuals (22.662.6 years) completed 3 trials of 3 carry positions (overhead, frontracked, and suitcase) with 3 load conditions (light, moderate, and heavy) across a twelve-meter distance with the dumbbell held on the subject’s dominant side. Electromyographic data were collected on the dominant upper (UT) and lower trapezius (LT), latissimus dorsi (LD), and serratus anterior (SA) as well as bilateral GM and EO. Repeated measures analysis of variance revealed a significant load by muscle interaction [F(14, 81.931) 5 15.474; p, 0.001; ηp² 5 0.477]. Follow-up pairwise comparisons revealed increased muscle activation with increased load acrossmostmuscles. There was also a significantmuscle by position interaction for bilateralGMand EO [GM: F(1.157, 19.662) 520.240; p,0.001; ηp² 50.544] [EO: F(1.302, 22.129)525.620; p,0.001; ηp² 50.601]. Post-hoc analysis revealed bilateral differences in muscle activation for the GM in the suitcase position and for the EO in the overhead and suitcase position, where the nondominant side showed significantly greater activation (all p, 0.039). These findings suggest unilateral carries may be used to target LPHC and scapular muscle activation; however, load and carry position should be considered because variations affect muscle activation. [ABSTRACT FROM AUTHOR]

Verbal instruction increases electromyographic (EMG) activity in the first three repetitions of an exercise, but its effect on an entire exercise set until failure is unknown. Once there are changes in motor unit recruitment due to fatigue, the effect of verbal instructions can change during different intervals of a set. This study analyzed whether verbal instruction emphasized the contraction of back muscles (i.e., myoelectric activity) during initial, intermediate, and final exercise repetitions performed until failure. Twenty participants with little or no experience in strength training performed a seated row exercise with and without verbal instruction. Surface electrodes were fixed over the latissimus dorsi, teres major, biceps brachii, and posterior deltoid (PD) muscles. Myoelectric activity was computed by mean amplitude and by the median frequency. We analyzed data with repeated measures multivariate analysis of variance and found that, with verbal instruction, there was increased EMG mean amplitude in the latissimus dorsi (15.21%, p =.030) and reduced EMG mean amplitude in the PD (14.39%, p =.018) on initial repetitions. Other muscle EMG amplitudes did not change. On intermediate repetitions, there was reduced signal amplitude only in the PD (15.03%, p =.022). The verbal instruction did not interfere with signal amplitude on final repetitions nor in the median frequency throughout the series. Verbal instruction seems to have little effect on increasing myoelectric activity of these targeted muscles in an entire set of a resistance training. [ABSTRACT FROM AUTHOR]

Purpose: Latissimus dorsi tendon transfer is a surgical option for the treatment of massive irreparable posterosuperior rotator cuff tear. Whether a favourable clinical outcome is due to the latissimus dorsi muscle contraction rather than the passive tenodesis effect remains to be confirmed. The purpose of the current case-control study was to evaluate the shoulder kinematics and latissimus dorsi activation after latissimus dorsi tendon transfer.Methods: Eighteen patients suffering from irreparable rotator cuff tear that underwent latissimus dorsi tendon transfer and 18 healthy individuals were examined using a 3D kinematic tracking system and electromyography. Active maximal flexion-extension and abduction-adduction of the humerus were measured for the operated and the contralateral shoulder of the patients and the shoulder of healthy individuals to evaluate the range of motion (ROM) and scapulohumeral rhythm. Electromyographic comparison of isometric contraction between the latissimus dorsi of the operated and contralateral shoulder was carried out.Results: After arthroscopic-assisted latissimus dorsi tendon transfer, patients showed comparable flexion and abduction ROM to their asymptomatic contralateral shoulders and to the shoulders of healthy individuals. Significantly higher scapular ROM values were found between the latissimus dorsi tendon transfer side and the shoulders of healthy individuals. While performing external rotation with 0° shoulder abduction, a greater percentage of the electromyographic peak value (p = 0.047) and a higher latissimus dorsi internal/external rotation ratio (p = 0.004) were noted for the transferred muscle in comparison to the contralateral shoulder.Conclusion: Although the arthroscopic-assisted latissimus dorsi tendon transfer failed to normalize scapulothoracic joint movements of patients, a functional latissimus flap and a shoulder ROM similar to the contralateral side or the shoulder of healthy individuals can be expected after this procedure in patients with massive irreparable posterosuperior rotator cuff tear.Level Of Evidence: III. [ABSTRACT FROM AUTHOR]

The objective of the present study was to determine the structure of the movement pattern performed during a wheelchair fencing lunge that is executed in response to visual and sensory stimuli. In addition, a comparison was made between fencers in the categories A and B of disability. In addition, the analysis involved the correlation between the duration of the sensorimotor response and the value of the bioelectric signal recorded in selected muscles. Seven Paralympic team athletes specializing in wheelchair fencing (3 in category A and 4 in category B) participated in the research. The fencers perform at international level competitions and are multiple medalists of the Paralympic Games. In the study, a wireless system for sEMG and accelerometer signal measurement was employed to test the intervals between the initiation of the lunge attack and its termination defined by the touch of the weapon on the coach's torso. The electrodes were placed on 9 key muscles responsible for the effectiveness of the executed attack: DEL, TRI, BC, ECR FCR, LD, and EAO. The significant intergroup difference in the muscle activation was found to be 0.333 s for category A fencers and 0.522 s for category A fencers at p = 0.039 applies to the latissimus dorsi (LD LT) muscle, which demonstrates its significance as a postural muscle in the structure of the examined movement pattern. In terms of the values of EMG, a tendency for higher MVC (%) values in most muscles for category A competitors was recorded. The latissimus dorsi (DL RT) muscle with an intergroup difference of MVC-114.63 for cat. A and 67.50 for cat. B at p = 0.039 turned out to play a significant role. The results prove the role of postural muscles: external abdominal oblique and latissimus dorsi on the effectiveness of the attacks executed in wheelchair fencing. [ABSTRACT FROM AUTHOR]

Background: There are various overhead injuries which mainly affect the shoulder complex in swimmers and one among them is sick scapula syndrome which results in muscular imbalance in such athletes. The abbreviation SICK stands for Scapular malposition, Inferior medial border prominence, Coracoid pain and malposition, Dyskinesia. Method: In this study 26 subjects with sick scapula syndrome were taken into the study by evaluating through the lateral scapular slide test (LSST), the subjects affected were given muscle energy technique to increase the strength of the scapular muscles the technique was given for 45-60 seconds thrice in a week for three weeks and all the subjects were immediately assessed using MMT. Results: The t and p value of Pre and Post ROM scale of Extension was 11.523 and 0.001. The t and p value of Pre and Post ROM scale of Internal rotation was 10.490 and 0.001. The t and p value of Pre and Post ROM scale of external rotation was 12.569 and 0.001 which is statistically significant. The t and p value of Pre and Post MMT scale of serratus anterior was 1.995 and 0.050. The t and p value of Pre and Post MMT scale of Pectoralis Minor was 5.000 and 0.001. The t and p value of Pre and Post MMT scale of Latissimus dorsi was 2.440 and 0.022. The t and p value of Pre and Post MMT scale of Trapezius was 6.325 and 0.001 which is statistically significant. Conclusion: The present study results demonstrate that of Muscle energy techniques effective in increasing the range of motion and strength in young swimmers within the age group of 8 to 15 years with sick scapular syndrome. [ABSTRACT FROM AUTHOR]

This study investigated whether using an inertial measurement unit (IMU) can identify different walking conditions, including level walking (LW), descent (DC) and ascent (AC) slope walking as well as downstairs (DS) and upstairs (US) walking. Thirty healthy participants performed walking under five conditions. The IMU was stabilised on the exterior of the left shoe. The data from IMU were used to establish a customised prediction model by cut point and a prediction model by using deep learning method. The accuracy of both prediction models was evaluated. The customised prediction model combining the angular velocity of dorsi–plantar flexion in the heel-strike (HS) and toe-off (TO) phases can distinctly determine real conditions during DC and AC slope, DS, and LW (accuracy: 86.7–96.7%) except for US walking (accuracy: 60.0%). The prediction model established by deep learning using the data of three-axis acceleration and three-axis gyroscopes can also distinctly identify DS, US, and LW with 90.2–90.7% accuracy and 84.8% and 82.4% accuracy for DC and AC slope walking, respectively. In conclusion, inertial measurement units can be used to identify walking patterns under different conditions such as slopes and stairs with customised prediction model and deep learning prediction model. [ABSTRACT FROM AUTHOR]

Surfers spend a majority of their time in the water paddling. The purpose of this study was to examine activity in 5 muscles that contribute to paddling at different velocities and to characterize oxygen use, paddling cadence, and surfboard motion at each velocity. Twelve recreational surfers completed an incremental paddling test on a short surfboard in a swim flume. Surface electromyography was recorded bilaterally from latissimus dorsi, upper and mid trapezius, and posterior and mid deltoid. Electromyographic activity increased as water velocity increased for all muscles, but the change in activation between endurance and sprint paddling was greatest for latissimus dorsi (p < 0.001). At higher water velocities, the middle deltoid was activated earlier in the paddling stroke (p = 0.005). Oxygen use, paddling cadence, and surfboard roll/yaw increased with increasing water velocity. These data may be useful for athletes, trainers, and equipment designers interested in increasing power and efficiency of the paddling stroke. [ABSTRACT FROM AUTHOR]

Proximal stability consists of core and hip stability play a significant role in supporting the body weight in stationary and in motion. Thus, proximal stability could contribute to knee osteoarthritis (OA). Therefore, this study was carried out to determine the core stability and hip stability of knee OA patients. A total of thirty-two women aged between 45 to 60 years had volunteered to participate in this study, comprised of 16 knee OA patients and 16 normal. Hip stability was assessed using hip crossover test and core stability was assessed using core muscle endurance, core muscle strength and core muscle flexibility. Data of hip stability, core muscle strength and flexibility were analyzed using chi-square; and core muscle endurance data were analyzed using independent sample t-test. Compared to normal subjects, knee OA patients have poor hip stability [Hip Crossover Test (λ=0.500, p=0.033)] and core stability. Core stability was assessed based on core muscle strength [abdominal muscles (χ=12.157, p<0.001); quadriceps and gluteal muscles (χ=13.364, p<0.001); hip muscles (χ=17.936, p<0.001); latissimus dorsi and quadriceps (χ=15.906, p<0.001)]; core muscle endurance [plank endurance (t=4.719, p<0.001); trunk flexion (t=2.824, p=0.008); trunk extension (t=1.364, p=0.193)]; core muscle flexibility [Ely's test (λ=0.438, p=0.010)]. The proximal stability of knee OA patients appears to be significantly weaker than normal subjects. Thus, core stability and hip stability training have high potential not only to lessen the symptoms of knee osteoarthritis but to improve the functional movement of knee OA patients. [ABSTRACT FROM AUTHOR]

Background: A lack of shoulder abduction in spontaneously recovered birth brachial plexus palsy (BBPP) is a common presentation. We have performed a soft tissue release operation in these patients to remove the tethering effect of the tight and cocontracting shoulder adductors. This study was undertaken in order to assess the outcome of this surgical procedure. Methods: We performed a retrospective analysis of 120 patients who displayed spontaneous recovery from BBPP and subsequently underwent soft tissue release procedure to improve shoulder abduction. The operation involved release of the pectoralis major, latissimus dorsi (LD) and teres major (TM) with axillary nerve neurolysis and transfer of LD and TM to teres minor at a lower position. Outcomes were assessed at a minimum follow up of two years. The primary outcome measures were range of shoulder abduction and Mallet score. Parents were interviewed and their satisfaction was graded on a Likert scale. We also explored prognostic factors responsible for better outcomes namely, age at operation, extent of involvement; preoperative shoulder abduction range, internal rotation deformity, triceps power and Mallet score. Results: The average patient age was 5.8 years(range 1-17). Follow up ranged from 2-6 years. Average preoperative shoulder abduction was 85° (range 30°-140°). Postoperatively the average shoulder abduction was 161° (range 80°-180°). The mean improvement in abduction was 76° (range 20°-110°) [ p < 0.001]. Mallet score improved from 16.4 to 19.5 ( p < 0.001). High parental satisfaction was recorded by Likert scale assessment. Regression analysis indicated a favourable outcome in patients who are younger, have a better preoperative abduction range and a preoperative triceps power > grade 3. Conclusions: Soft tissue release procedure employed in this series is effective in improving shoulder abduction. Patients who are of younger age, have better preoperative abduction and triceps power of > grade 3 are expected to achieve the best outcome. [ABSTRACT FROM AUTHOR]

Eulerian Video Magnification (EVM) can enhance subtle changes in videos to reveal what was once invisible to the naked eye. In this proof of concept study, we investigated using EVM as a novel form of free flap monitoring. Free flaps with skin paddles were filmed in the operating room with manipulation of their pedicles. In a representative 77-year-old female who received a latissimus dorsi-serratus-rib composite free flap, EVM was able to detect blockage of arterial or venous supply instantaneously, providing a visible representation through degree of color change in videos. EVM has the potential to serve as a powerful free flap monitoring tool with the benefit of being noninvasive, sensitive, easy-to-use, and nearly cost-free. [ABSTRACT FROM AUTHOR]

It is generally accepted that playing with fatigue is a primary predictor of injury in youth baseball because muscular fatigue is believed to alter mechanics during the arm cocking and acceleration phases. Therefore, the purpose of this study was to quantitatively describe gluteal and upper extremity muscle activations in youth baseball pitchers during a simulated game. Twenty-three youth baseball players (11.2±0.8 years; 151.4±8.7 cm; 47.5±10.8 kg) participated. Data were collected through a Delsys Bagnoli-8-channel electromyography system. Single differential electrodes (interelectrode distance: 10 mm) were attached to the bilateral gluteus maximus and medius and throwing side latissimus dorsi, lower trapezius, and serratus anterior and upper trapezius. After warm-up, participants were instructed to throw randomly provided game situations over a regulation distance (46 feet; 14.02 meters) to a catcher. Three, 4-seam fastballs for strikes, thrown in the first and last innings of the simulated game were selected for analysis. A multivariate analysis of variance revealed no statistically significant differences in muscle activity at the 3 phases of the throw, between first and last innings of the simulated game with an observed power of 0.274 (phase 1: foot contact to maximum shoulder external rotation), 0.297 (phase 2: maximum shoulder external rotation to ball release), and 0.226 (phase 3: ball release to maximum shoulder internal rotation). Examining muscle activations as a pitcher approaches fatigue provides information on how long a pitcher can perform before mechanical alterations occur. Although this study did not reveal significant changes, it did reiterate the fact that pitch counts may be working in possibly preventing a youth pitcher throwing to fatigue. [ABSTRACT FROM AUTHOR]

The upper body trunk musculature is key in supporting breathing, propulsion, and stabilization during front crawl swimming. The aim of this study was to determine if the latissimus dorsi, pectoralis major, and serratus anterior contributed to the development of inspiratory muscle fatigue observed following front crawl swimming. Fourteen trained swimmers completed a 200-m front crawl swim at 90% of race pace. Maximal inspiratory and expiratory mouth pressures ( PImax and PEmax) were assessed before (baseline) and after each swim, and electromyography was recorded from the three muscles. Post-swim PImax fell by 11% ( P < 0.001, d = 0.57) and the median frequency ( MDF: a measure of fatigue) of the latissimus dorsi, pectoralis major, and serratus anterior fell to 90% ( P = 0.001, d = 1.57), 87% ( P = 0.001, r = −0.60) and 89% ( P = 0.018, d = 1.04) of baseline, respectively. The fall in serratus anterior MDF was correlated with breathing frequency ( r = 0.675, P = 0.008) and stroke rate ( r = 0.639, P = 0.014). The results suggest that the occurrence of inspiratory muscle fatigue was partly caused by fatigue of these muscles, and that breathing frequency and stroke rate particularly affect the serratus anterior. [ABSTRACT FROM AUTHOR]

Because there is little agreement as to which exercise is the most effective for activating the latissimus dorsi, and its intramuscular components are rarely compared, we investigated the intramuscular components of the latissimus dorsi during both trunk and shoulder exercises. Sixteen male subjects performed four isometric exercises: inverted row, body lifting, trunk extension, and trunk lateral bending. Surface electromyography (sEMG) was used to collect data from the medial and lateral components of the latissimus dorsi, lower trapezius, and the erector spinae at the 12th thoracic level during the isometric exercises. Two-way repeated analysis of variance with two within-subject factors (muscles and exercise conditions) was used to determine the significance of differences between the muscles and differences between exercise variations. The inverted row showed the highest values for the medial latissimus dorsi, which were significantly higher than those of the body lifting or trunk extension exercises. For the lateral latissimus dorsi, lateral bending showed significantly higher muscle activity than the inverted row or trunk extension. During body lifting, the % maximum voluntary isometric contraction (MVIC) of the erector spinae showed the lowest value, significantly lower than those of the other isometric exercises. The inverted row exercise was effective for activating the medial latissimus dorsi versus the shoulder depression and trunk exertion exercises. The lateral bending and body lifting exercises were favorable for activating the lateral component of the latissimus dorsi. Evaluating trunk lateral bending is essential for examining the function of the latissimus dorsi. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the effects of antagonist passive static stretching (AS) during the inter-set rest period on repetition performance and muscle activation. Ten trained men (22.4 ± 0.9 years) participated in this study. Two protocols were adopted: Passive recovery (PR) – three sets to repetition failure were performed for the seated row (SR) with two-minute rest interval between sets without pre-exercise stretching; AS – forty seconds of stretching was applied to pectoralis major prior to each set of SR. Significant increases in the number of repetitions were noted under AS compared with PR (p < 0.05). Significant increases on latissimus dorsi (p = 0.002) and biceps brachii (p = 0.001) muscle activity were noted inter-sets under the AS compared with the PR condition. Therefore, the AS adopted during the inter-set rest period may enhance repetition performance and activation of agonist muscles in an acute manner. [ABSTRACT FROM AUTHOR]

The article discusses research which compared six repetition maximum load and electromyographic activity in the lat pull-down using 3 different pronated grip widths and evaluated the effects grip width had on muscle strength and activation in the lat pull-down. Researchers evaluated 15 men who performed lat pull-downs with three grips. They found that a medium grip may have some minor advantages over small and wide grips but that similar muscle activation was seen with all grips.

The purpose of this study was to compare kinematics and muscle activity between chin-ups and lat-pull down exercises and between muscle groups during the two exercises. Normalized electromyography (EMG) of biceps brachii (BB), triceps brachii (TB), pectoralis major (PM), latissimus dorsi (LD), rectus abdominus (RA), and erector spinae (ES) and kinematics of back, shoulder, and seventh cervical vertebrae (C7) was analysed during chin-ups and lat-pull down exercises. Normalized EMG of BB and ES and kinematics of shoulder and C7 for chin-ups were greater than lat-pull down exercises during the concentric phase (p < 0.05). For the eccentric phase, RA during lat-pull down exercises was greater than chin-ups and the kinematics of C7 during chin-ups was greater than lat-pull down exercises (p < 0.05). For chin-ups, BB, LD, and ES were greater than PM during the concentric phase, whereas BB and LD were greater than TB, and LD was greater than RA during the eccentric phase (p < 0.05). For lat-pull down exercise, BB and LD were greater than PM, TB, and ES during the concentric phase, whereas LD was greater than PM, TB, and BB during the eccentric phase (p < 0.05). Subsequently, chin-ups appears to be a more functional exercise. [ABSTRACT FROM PUBLISHER]

This study aimed at investigating the influence of three rackets on shoulder net joint moments, power and muscle activity during the flat tennis serve under field-conditions. A 6-camera Eagle® motion analysis system, operating at 256 Hz, captured racket and dominant upper limb kinematics of the serve in five tennis players under three racket conditions (A: low mass, high balance and polar moment, B: low three moments of inertia, and C: high mass, swingweight and twistweight). The electromyographic activity of six trunk and arm muscles was simultaneously recorded. Shoulder net joint moments and power were computed by 3D inverse dynamics. The results showed that greater shoulder joint power and internal/external rotation peak moments were found to accelerate and decelerate racket A in comparison with the racket C. Moreover, serving with the racket A resulted in less activity in latissimus dorsi muscle during the acceleration phase, and biceps brachii muscle during the follow-through phase when compared with racket C. These initial findings encourage studying the biomechanical measurements to quantify the loads on the body during play in order to reduce them, and then prevent shoulder injuries. Racket specifications may be a critical point for coaches who train players suffering from shoulder pain and chronic upper limb injuries should be considered in relation to the racket specifications of the players. [ABSTRACT FROM AUTHOR]

The latissimus dorsi is the larger, flat, dorso-lateral muscle on the trunk, posterior to the arm, and partly covered by the trapezius on its median dorsal region. Origin of the latissimus dorsi is from spinous processes of thoracic T7-T12, thoracolumbar fascia, iliac crest and inferior 3 or 4 ribs, inferior angle of scapula and insertion on floor of intertubercular groove of the humerus. We have studied 50 cadavers in the different medical colleges in which we found 2% case of anterior and posterior slip of the muscle fibers with their extension up to the pectoralis major and teres major respectively. Usually, latissimus dorsi involve in extension, adduction, transverse extension also known as horizontal abduction, flexion from an extended position, and internal rotation of the shoulder joint. It also has a synergistic role in extension and lateral flexion of the lumbar spine. The latissimus dorsi maybe used for the tendon graft surgeries. Tight latissimus dorsi has been shown to be one cause of chronic shoulder pain and chronic back pain. Because the latissimus dorsi connects the spine to the humerus, tightness in this muscle can manifest as either sub-optimal glenohumeral joint function (which leads to chronic shoulder pain) or tendinitis in the tendinous fasciae connecting the latissimus dorsi to the thoracic and lumbar spine. Latissimus dorsi used for pedicle transplant rotator cuff repair reconstruction of breast, face, scalp and cranium defect. The extra slip of the latissimus dorsi may puzzle any transplant operations. We as anatomist discuss the clinical implication of the extra slip of latissimus dorsi. [ABSTRACT FROM AUTHOR]

Context: The prevalence of shoulder pain among competitive swimmers is high, but no guidelines exist to reduce shoulder injuries. Elucidating differences between swimmers with and without shoulder pain can serve as a basis for the development of a program to prevent shoulder injury that might lead to pain and dysfunction. Objective: To determine whether physical characteristics, exposure, or training variables differ between swimmers with and without shoulder pain or disability. Design: Cross-sectional study. Setting: Multisite swimming centers. Patients or Other Participants: A total of 236 competitive female swimmers aged 8 to 77 years. Data Collection and Analysis: Participants completed the Penn Shoulder Score and underwent testing of core endurance, range of motion, muscle force production, and pectoralis minor muscle length and the Scapular Dyskinesis Test. Swimmers were grouped by age for analysis: ages 8 to 11 years (n = 42), 12 to 14 years (n = 43), 15 to 19 years (high school, n = 84), and 23 to 77 years (masters, n = 67). Comparisons were made between groups with and without pain and disability using independent t tests for continuous data and X2 analyses and Fisher exact tests for categorical data. Results: Nine (21.4%) swimmers aged 8 to 11 years, 8 (18.6%) swimmers aged 12 to 14 years, 19 (22.6%) high school swimmers, and 13 (19.4%) masters swimmers had shoulder pain and disability. Differences that were found in 2 or more age groups between athletes with and without shoulder pain and disability included greater swimming exposure, a higher incidence of previous traumatic injury and patient-rated shoulder instability, and reduced participation in another sport in the symptomatic groups (P<.05). Reduced shoulder flexion motion, weakness of the middle trapezius and internal rotation, shorter pectoralis minor and latissimus, participation in water polo, and decreased core endurance were found in symptomatic females in single varying age groups (P<.05). Conclusions: Female competitive swimmers have shoulder pain and disability throughout their lives. Given that exposure and physical examination findings varied between athletes with and without substantial pain and disability, a program to prevent shoulder injury that might lead to pain and dysfunction appears warranted and might include exposure reduction, cross-training, pectoral and posterior shoulder stretching, strengthening, and core endurance training. [ABSTRACT FROM AUTHOR]

Injuries due to manual valve handwheel operations are a major concern in the chemical process industry. Manual valves are used to start, stop, and control flow in process lines. The torque required to operate handwheels after the initial 'breaking' can vary due to the size, design, and condition of the valve. This study tested four methods of turning the handwheel on a medium-sized gate valve at two different torque requirements (25 Nm and 50 Nm). The methods were compared to each other, in terms of efficiency, subjective ratings of perceived exertion, and electromyography activity of the upper extremity and trunk muscles. The results indicate that different methods and torque requirements are compensated for by the use of different muscles. Also, this use of different muscles, along with the increased mechanical advantage of the wrench, can affect the operator's actual and perceived comfort and efficiency while operating a valve handwheel. [ABSTRACT FROM AUTHOR]

Background: Despite considerable medical advances, arthroscopy remains the only definitive means of superior labrum anterior-posterior (SLAP) lesion diagnosis. Natural shoulder anatomic variants limit the reliability of radiographic findings and clinical evaluations are not consistent. Accurate clinical diagnostic techniques would be advantageous because of the invasiveness, patient risk, and financial cost associated with arthroscopy.Purpose: The purpose of this study was to examine the behavior of the joint-stabilizing muscles in provocative tests for SLAP lesions. Electromyography was used to characterize the muscle behavior, with particular interest in the long head of the biceps brachii (LHBB), as activation of the long head and subsequent tension in the biceps tendon should, based on related research, elicit labral symptoms in SLAP lesion patients.Study Design: Controlled laboratory study.Methods: Volunteers (N = 21) without a history of shoulder injury were recruited. The tests analyzed were active compression, Speed’s, pronated load, biceps load I, biceps load II, resisted supination external rotation, and Yergason’s. Tests were performed with a dynamometer to improve reproducibility. Muscle activity was recorded for the long and short heads of the biceps brachii, anterior deltoid, pectoralis major, latissimus dorsi, infraspinatus, and supraspinatus. Muscle behavior for each test was characterized by peak activation and proportion of muscle activity.Results: Speed’s, active compression palm-up, bicep I, and bicep II produced higher long head activations. Resisted supination external rotation, bicep I, bicep II, and Yergason’s produced a higher LHBB proportion.Conclusion: Biceps load I and biceps load II elicited promising long head behavior (high activation and selectivity). Speed’s and active compression palm up elicited higher activation of the LHBB, and resisted supination and Yergason’s elicited selective LHBB activity. These top performing tests utilize a unique range of test variables that may prove valuable for optimal SLAP test design and performance.Clinical Relevance: This study examines several provocative tests that are frequently used in the clinical setting as a means of evaluating a potential SLAP lesion. [ABSTRACT FROM AUTHOR]

Background: Clinical testing for the integrity of the subscapularis muscle includes the belly-press, lift-off, and bear-hug examinations. While these tests have been widely applied in clinical practice, there is considerable variation in arm positioning within each clinical examination.Hypothesis: To determine the ideal arm and shoulder positions for isolating the subscapularis muscle while performing the bear-hug, belly-press, and lift-off tests.Study Design: Controlled laboratory study.Methods: The activity of 7 muscles was monitored in 20 healthy participants: upper and lower divisions of the subscapularis, supraspinatus, infraspinatus, latissimus dorsi, teres major, triceps, pectoralis major. Electromyogram data were collected and compared across each clinical test at varying arm positions: bear-hug (ideal position, 10° superior, 10° inferior to the shoulder line), belly-press (ideal position, maximum shoulder external rotation, and maximal shoulder internal rotation), and lift-off (ideal position, hand position 5 in. [12.7 cm] superior and 5 in. [12.7 cm] inferior to the midlumbar spine).Results: Regardless of arm and shoulder position, the upper and lower subscapularis muscle activities were significantly greater than all other muscles while performing each test. No significant differences were observed between the upper and lower subscapularis divisions at any position within and across the 3 tests. There were no significant differences in subscapularis electromyogram activities across the 3 tests.Conclusion: The level of subscapularis muscle activation was similar among the bear-hug, belly-press, and lift-off tests. The 3 tests activated the subscapularis significantly more than all other muscles tested but were not different from one another when compared across tests and positions. Although the bear-hug and lift-off tests have been described to activate differential portions of the subscapularis, the findings of this study do not support the preferential testing of a specific subscapular division across the 3 tests. As such, all 3 tests are effective in testing the integrity of the entire subscapularis muscle, although there does not appear to be an ideal position for selectively testing its divisions.Clinical Relevance: Clinicians may feel comfortable in using any of the 3 tests, depending on the patient, to isolate the function of the subscapularis as a single muscle. Furthermore, clinicians should not solely focus on a patient’s arm position when administering an examination but also compare the affected arm to the contralateral shoulder when appropriate. [ABSTRACT FROM PUBLISHER]

The purpose of this study was to evaluate the effects of whole-body vibration (WBV) on the muscle recruitment of selected upper and lower body muscles during the baseball swing. Participants were recreationally trained males (n = 16, 22 ± 2 years, 181.4 ± 7.4 cm, 84.7 ± 9.0 kg), with previous baseball experience. Subjects participated in three randomized sessions on separate days, consisting of three sets of five swings off a hitting tee. Exercises (upper and lower body dynamic and static movements) with or without WBV exposure were performed between swing sets. During each swing, the gastrocnemius, biceps femoris, gluteus maximus, pectoralis major, latissimus dorsi, and triceps brachii were evaluated for electromyographic (EMG) activity. EMG values were normalized to EMG measured during maximal voluntary isometric contraction. Statistical analysis revealed no significant differences in EMG activity across the three treatments. In addition, the results displayed a specific muscle recruitment order during the swing, starting with the lower body followed by the upper body muscles. This study was the first to report the recruitment order during the baseball swing. Although acute exposure to WBV did not significantly alter the muscle recruitment, these results may prove useful for practitioners looking to enhance baseball swing performance. [ABSTRACT FROM PUBLISHER]

Age-related decline in muscle strength affects both upper and lower extremities. This decline is associated with late-life onset of physical disability. Although progressive resistance strength training (PRT) has shown promising results in lower-extremity-related physical function, such as walking speed, little is known about the effect on upper-extremity-related physical function. This study reviewed 28 randomized controlled trials published before 2008. Outcomes of upper-extremity muscle strength, hand-grip strength, eye-hand coordination, and physical function were appraised. It is hard to conclude whether or not upper-extremity PRT is beneficial for upper-extremity-related physical function in older adults because the specific effect of upper extremities was often unmeasured, poorly measured with timed tests, or buried in mixed results of upper and lower extremities. Additional research that focuses on examining the effect of upper-extremity PRT is recommended to support the need for a comprehensive muscle strength training program. [ABSTRACT FROM AUTHOR]

Developed from traditional Chinese martial arts, Tai Chi exercise includes different forms and interactive Push Hands but biomechanical analyses have focused on the former only. To analyse the techniques of Push Hands, an experienced master was asked to defend pushing by four opponents. Movements were videotaped and digitized using a motion analysis system. Surface electrodes were used to record the electromyographic activity of ten muscle groups. Two force plates were used to measure the ground reaction force on each foot. Inexperienced individuals performed the same procedure to serve as the control group. The results indicate that the master adopted a postural adjustment to maintain balance. A clear shift of body weight from the front to the rear foot and mediolateral displacement of the centre of gravity was observed. Low electromyographic activity was observed in the upper body muscle groups, while high electromyographic activity was observed in the right rectus femoris and very high activity in the left rectus femoris during the defence. All inexperienced participants lost their balance in resisting pushing. It is concluded that the Tai Chi defensive technique includes a subtle postural adjustment that slightly changes the pushing force direction, and allows the rear leg to resist the incoming force. [ABSTRACT FROM AUTHOR]

The article presents the case study of a 29-year-old professional beach volleyball player with right posterolateral shoulder pain.

Background Evidence-based practice requires the use of objective, valid and reliable tests for measuring the length of a muscle. Latissimus Dorsi is a muscle which undergoes length changes (loss of extensibility) and this muscle has a functional role in many aspects of sport and rehabilitation. The loss of extensibility may result in a decreased range of motion at the glenohumeral joint leading to dysfunction. Objectives The aim of this study was to assess the inter-rater and intra-rater reliability of a technique adapted by Comerford and Mottram in 2012 for assessing the length of Latissimus Dorsi (LD) muscle. Method Fifty-six students from a university's physiotherapy department participated in this study. Four physiotherapists with clinical experience varying between 10 and 30 years independently performed the test for assessing the length of LD. The test was performed twice by each physiotherapist on every participant during two reading sessions. Results The intra-class correlation coefficient (ICC) as determined in a mixed-effects, generalised least squares regression analysis was used to assess inter- and intra-rater reliability of the LD length test. A 0.05 level of significance was employed. A sample of 56 participants provided an ICC that varied between 0.76 and 0.55, which is regarded as moderate to poor reliability. The ICC between the experienced raters was found to be 0.48, with a novice rater having an ICC of 0.48 as well. The ICC between all the raters was 0.33, which constituted poor reliability. Conclusion The poor to moderate reliability of the technique testing the length of LD test is not suitable for application in a research setting. Clinical implications The small differences noted between Reading 1 and Reading 2 regarding the standard deviation of all the raters combined suggests that the LD length test may still prove to be useful in quantifying dysfunction in a clinical setting. [ABSTRACT FROM AUTHOR]

Background: Evidence-based practice requires the use of objective, valid and reliable tests for measuring the length of a muscle. No evidence of reliability for any technique testing the length of Latissimus Dorsi (LD) was found. Purpose: To assess the inter-rater and intra-rater reliability of a technique adapted by Comerford and Mottram (2012) for assessing the length of LD. Methods: Fifty-six students from the University of Pretoria's Physiotherapy Department were the participants in this study. Four physiotherapists with varying numbers of years of clinical experience independently performed the test for assessing the length of LD. The test was performed twice by each physiotherapist on every participant and two measurement sessions took place. A pilot study wascarried out to test and time the procedure. The intra-class correlation coefficient(ICC) as determined in a mixed-effects GLS regression analysis was used to assess the inter and intra rater reliability of the LD length test. A 0.05 level of significance was employed. Major Results: A sample of 56 participants provided an intraclass correlation coefficient (ICC) that varied between 0.55 and 0.76 and this is regarded as moderate to poor reliability.. The ICC between the experienced raters was found to be 0.48, with a novice rater having an ICC of 0.48 as well. The ICC between all the raters was 0.33. Conclusion: The poor reliability of the technique testing the length of LD was identified and addressed in order for adequate usage thereof, in research and in practice. Recommendations were made. [ABSTRACT FROM AUTHOR]