Differences in Shoulder Internal Rotation Strength Between Baseball Players With Ulnar Collateral Ligament Reconstruction and Healthy Controls

Background: Studies have indicated decreased shoulder internal rotation (IR) and external rotation (ER) strength in the throwing limb of baseball players after ulnar collateral ligament injury. There is limited evidence on the recovery of shoulder rotation strength after primary ulnar collateral ligament reconstruction (UCLR). Hypothesis: At the time of return to throwing, baseball players who underwent UCLR would demonstrate decreased IR and ER shoulder strength in the throwing arm as compared with healthy baseball players. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Male competitive high school and collegiate baseball athletes participated in this study. Athletes who underwent UCLR were compared with healthy controls who were matched by age, height, weight, and position. Bilateral isometric shoulder ER and IR strength was measured using a handheld dynamometer for all participants at the time of initial evaluation (UCLR group) and throughout the course of a season (healthy group). Independent t tests were run to calculate mean differences in ER and IR shoulder strength between the groups, with significance set at P < .05. Results: A total of 86 baseball athletes participated in this study (43 UCLR group, 43 healthy group). At the time of return to throwing (mean ± SD, 194 ± 30 days postoperatively), the 2 groups demonstrated no significant differences in nonthrowing arm ER or IR strength ( P = .143 and .994, respectively). No significant difference was found between groups for throwing arm ER strength ( P = .921); however, the UCLR group demonstrated significantly less throwing arm IR strength than the healthy group (144.2 ± 27.8 vs 157.6 ± 27.1 N; P = .023). Conclusion: The results of this study demonstrate that throwing arm rotator cuff strength may not fully recover before the initiation of a return-to-throwing program after UCLR. These data provide a potential framework for clinicians to assist in the management and exercise prescription of the baseball athlete after UCLR and before medical release and the initiation of a return-to-throwing program.

Assessment of Isokinetic Knee and Shoulder Strength in Elite Youth Boxers: Correlation with Punch Impact Force

This study aimed to assess the isokinetic strength performance of the knee and shoulder in amateur boxer, and further to explore the contribution of knee and shoulder peak torque to different punches. Boxers (6 females and 8 males) were measured the dynamic concentric torque of knee flexion(F) and extension(E), shoulder external rotation (ER) and internal rotation (IR) at 60°/S, 180°/S. We tested the punching force of three techniques by Kistler Instruments. At 60°/S, F/E ratios of the dominant (D) knee of female boxers were lower than those of non-dominant (ND) side (p=0.03). At two angular velocities, all boxers demonstrated higher ER/IR ratios in ND (p=0.011 for males, p=0.025 for females). Bilateral difference of knee flexor in females was greater (p=0.038) than that in males. The maximum correlation was found at 180°/S between punching forces and the joints strength. ANOVA analyses revealed that athletes with greater punching force tend to have higher knee strength. Although correlations between shoulders strength and punching forces were strong, they did not discriminate between athletes who punched with higher punching force. In order to effectively transfer muscle strength to punching force, rapid completion of action should be highlighted in strength training, especially lower-limb strength.

Upper Limb Isokinetic Muscle Strength Predicts the Performance in Cross-Country Sit-Skiing

Understanding the physical fitness attributes in a sport-specific technical skill is a key to improve the action economy, and thus aerobic endurance performance. The present study was designed to investigate how upper limb muscle strength predicts double poling (DP) power performance in cross-country sit-skiing. A total of 19 female able-bodied college students (age 23.2±0.8 years, BMI 20.4±2.2) were subjected to a 30-s and 3-min DP performance tests using a sit-skiing ergometer. Isokinetic muscle strength by the angular velocity of 30 °/second, 60 °/second, and 120 °/second of the shoulder and elbow extensor/flexor were measured with an ISOMED2000 isokinetic system. A medium correlation was found between DP output power and isokinetic upper limb muscle strength (shoulder strength at all speed, r = 0.39-0.74, p < 0.1). Multiple regressions, which were employed to predict power production in the 30-s and 3-min tests, showed that shoulder extension strength at 60 °/second accounted for 34% of the variation in the 30-s test, and 40% of the variance in the 3-min test.

Determination of Ballistic Six Exercises and Theraband Exercises on Physical Performance in Badminton Players: A Randomized Controlled Clinical Trial

Aims: During regular training, players sustain injuries on a regular basis. Based on the fact that badminton isn't seem at all a contact sport the majority of ailments are caused by overuse. A participant must perform a variety of quick yet repeated shoulder actions and repetitive motions put tension mostly on tissues with time, putting them at risk of damage. Current study was done to compare the effects of Ballistic Six training and Theraband exercises on shoulder strength, agility, speed and function in novice badminton player. Study Design: Randomized Controlled Trial. Place and Duration of Study: Sport clubs were selected according to feasibility in Wardha, from July 2020 to June 2021. Methodology: 40 subjects of both gender aged between 18 to 25 years were selected who have being playing badminton for more than a year. Subjects were randomized into two groups, Group A (Ballistic Six Exercise group) and Group B (Theraband exercise group). Assessments done were sitting medicine ball throw test (SMBT) for shoulder strength, closed kinetic chain upper extremity stability test (CKUCEST) for agility, plate tapping test (PTT) for speed and Kerlan Jobe Orthopaedic Clinical Score (KJOC) for shoulder function. Assessments were done at baseline, post 8 weeks of training and at the end of 6 months. Results: Significant increase in mean sitting medicine ball throw test SMBT, CKUCEST, PTT and KJOC score in both group but Group A showed more improvement than Group B. Conclusion: Study concluded that adding of Ballisitic Six plyometric training for novice badminton players would increase the shoulder strength, agility, speed and function than the theraband exercises.

The Association between Radiologic Severity of Rotator Cuff Pathology and Supraspinatus Weakness on Biomechanical Assessment (229)

Objectives: Many different magnetic resonance imaging (MRI)-based classifications are used to characterize rotator cuff supraspinatus pathology, ranging from mild tendinopathy to full-thickness tears. While MRIs are chiefly utilized to guide the need for and approach to operative management of supraspinatus pathology, the functional implications, if any, across the entire range of pathologies have not been defined. The purpose of this biomechanical study was to examine shoulder strength and function in patients presenting with presumptive supraspinatus pathology and to determine if these clinical parameters are correlated with radiologic severity. Methods: We prospectively enrolled 171 patients with suspected rotator cuff pathology disease and without apparent strength deficit on traditional rotator cuff physical examination (PE). Exclusion criteria were radiographically apparent glenohumeral OA, previously diagnosed rotator cuff tear of the affected shoulder, previously diagnosed adhesive capsulitis, prior ipsilateral shoulder surgery, injury to the ipsilateral hand or wrist, limited range of motion, and history or radiographic evidence of anterior or posterior shoulder dislocation. For both clinical (e.g. testing isotonic strength in patients with frank weakness yields unreliable strength measurements and provides little useful information) and ethical (e.g. to avoid causing pain to patients already experiencing significant shoulder pain) reasons, this study evaluating dynamic strength testing was strictly limited to patients with negative traditional, static PE tests. All patients underwent two bilateral shoulder strength tests using dynamometry; first, isometric strength was measured at 90 degrees of abduction and, second, isotonic strength was measured eccentrically from full abduction throughout the full range of motion until the arm was at the patient’s side. For both of these tests, the examiner placed the handheld dynamometer (Hoggan microFET® 3; Hoggan Scientific, LLC, Salt Lake City UT, USA) on the patient’s wrist, perpendicular to the arm, to measure the force applied along the arc. Absolute strength and symptomatic-to-asymptomatic arm (S/A) strength ratios were calculated. All patients were included in analyses of absolute strength measurements on strength testing; patients who had a history or clinical evidence of contralateral shoulder pathology were excluded from analyses of S/A strength ratios. Patients then underwent shoulder MRI, classifying supraspinatus findings into one of seven ordinal categories. The primary outcome was the relationship between the radiologic severity of supraspinatus pathology on MRI and the degree of rotator cuff strength deficit upon exam. Results were analyzed for both isotonic and isometric function. Results: The study cohort consisted of 171 patients (102 [59.6%] males, 69 [40.4%] females). The mean patient age (± 95% CI) was 52.0 ± 1.9 years. The mean symptom duration (± 95% CI) was 10.8 ± 2.9 months. MRI revealed: 26 (15.2%) instances of no supraspinatus pathology, 37 (21.6%) instances of tendinopathy, 17 (9.9%) instances of supraspinatus fraying, 39 (22.8%) partial thickness tears (PTTs), 13 (7.6%) high-grade PTTs, 12 (7.0%) focal full thickness tears (FTTs)/full-thickness perforations, and 27 (15.8%) FTTs. Isotonic strength : Increasing imaging severity was significantly associated with decreasing absolute strength during isotonic testing ( P=0.036, Table 1). Specifically, absolute strength measurements declined with increasingly severe imaging findings, from no tear [59.9 N], to tendinopathy [50.9 N], to fraying [48.2 N], to PTT [55.0 N], to high-grade PTT [48.9 N], to focal FTT/full thickness perforation [45.7 N], to FTT [44.2 N]. Similarly, increasing imaging severity was significantly associated with decreasing S/A strength ratios during isotonic testing ( P=0.022, Table 1). Isotonic S/A strength ratios declined with increasingly severe imaging findings, from no tear [91.9%], to tendinopathy [70.8%], to fraying [66.1%], to PTT [76.2%], to high-grade PTT [75.7%], to focal FTT/full thickness perforation [65.2%], to FTT [63.3%]. Isometric strength : In contrast to isotonic testing, increasing imaging severity was not significantly associated with decreased absolute strength measurements on isometric testing ( P=0.12, Table 2). Similar results were seen for isometric S/A ratio, as increasing imaging severity was not significantly associated with S/A strength ratio ( P=0.085, Table 2). Conclusions: Radiologic severity of supraspinatus pathology was correlated with dynamic clinical function across the full range of pathology, revealing the functional importance of these frequently-used classifications. The lower discriminatory ability of isometric measurements and higher strength measurements on isometric assessment may be related to a greater role of compensatory musculature in static testing. These biomechanical results support the need for future work investigating the utility of dynamic rotator cuff physical examination maneuvers.

Relationship Differences in Pre-season Isometric Shoulder Strength, Humeral Torsion and Shoulder Range of Motion in Collegiate Baseball Players (218)

Objectives: Muscle strength, humeral torsion (HT) and shoulder range of motion (ROM) have been linked to throwing performance and injury risk in baseball players. Research suggests that players who demonstrate an isometric shoulder external rotation (ER)/internal rotation (IR) strength ratio of <0.75 are at a higher risk for developing a throwing-related upper extremity injury. While the relationships between HT and shoulder ROM have been examined in the literature, few studies have examined the potential relationships between these variables and isometric shoulder strength. The purpose of this study was to examine the relationships between isometric shoulder strength, HT and shoulder ROM at the start of each baseball season in a cohort of healthy junior college baseball players. Methods: Ninety-two healthy junior college baseball players (mean age=19.9±0.8 years) were prospectively assessed at the start of 2 consecutive spring seasons. Variables measured included HT, shoulder ROM and isometric shoulder strength. Both the dominant (D) and non-dominant (ND) shoulders of each player were assessed throughout the study. Chi square tests and bivariate Pearson correlation coefficients were calculated to examine between group differences and the relationships between variables. Statistical significance was set a priori at α=0.05. Results: 33.7% of junior college players demonstrated a D shoulder ER/IR strength ratio of <0.75 at the start of baseball season. Pitchers and position players demonstrated no significant differences in D shoulder ER/IR strength ratios at the start of the season (P=.40). Additionally, moderate positive relationships were observed between D HT and D IR ROM (r=0.35; P=.001) as well as D horizontal adduction (HA) ROM (r=0.43; P<.001). A moderate relationship was also observed between ND HT and ND IR ROM (r=0.56, P<.001), however ND ER and HA ROM demonstrated weaker relationships respectively (ER: r=-0.27; P=.01; HA: r=0.26; P=.01). Inverse relationships were observed between HT and ER strength in both the D and ND shoulders (D: r=-0.27, P=.01; ND: r=-0.28, P=.007). Internal rotation ROM was also inversely correlated with ER strength (r=-0.29, P=0.005) and ER/IR strength ratios (r=-0.31, P=.003), but only in the D shoulder. No significant correlations were observed between ROM and strength in the ND shoulder. Conclusions: One third of the junior college baseball players in this study began the season with marked deficits in D shoulder strength, irrespective of their position. We then examined the relationships between HT, shoulder ROM and isometric shoulder strength and confirmed the previously established correlation between HT and shoulder ROM. Moreover, there appeared to be inverse relationships between HT and ER strength in both the D and ND shoulders as well as IR ROM and ER strength in the D shoulder. This study emphasizes the importance of pre-season rotator cuff strength training, with an emphasis on improving ER strength, to potentially aid in the prevention of throwing-related upper extremity injuries in collegiate baseball players. Humeral torsion and shoulder ROM may influence isometric shoulder strength, however more research is needed to better understand these relationships in the throwing shoulder.

LAND BASED EXERCISES VERSUS POOL BASED EXERCISES FOR SWIMMER’S SHOULDER IN COMPETITIVE SWIMMERS: RANDOMIZED CLINICAL TRIAL

To compare the effect of Land based exercises and Pool based exercises for shoulder strength to reduce shoulder pain in competitive swimmers using Shoulder Pain Disability Index (SPADI) score, Hand-Held dynamometer (HHD), Randomized Clinical trial.29 competitive swimmers with age group between 8 to 18 years were evaluated for shoulder pain using Shoulder Pain Disability Index Score [SPADI] and shoulder strength was evaluated using Hand Held Dynamometer [HHD] before and after the study. Then all the subjects were divided into 2 groups, for Group A Pool based exercises were given and for Group B Land based exercises were given. Statistically there is significant difference in values of outcome measures after the study in both groups but there is more significant difference in Group A than Group B. Pool based exercises showed more significant effect on shoulder pain than land based exercises in swimmer’s shoulder.

Shoulder Isokinetic Strength Deficit in Patients with Neurogenic Thoracic Outlet Syndrome

Neurogenic thoracic outlet syndrome (NTOS) is an impairing painful condition. Patients usually report upper-limb pain, weakness and paresthesia. Shoulder weakness is frequently reported but has never been described with objective strength evaluation. We aimed to compare isokinetic shoulder strength between patients with NTOS and healthy controls. Patients and controls were prospectively evaluated with an isokinetic strength test at 60 and 180°/s, and an endurance test (30 repetitions at 180°/s) of the shoulder rotators. Patients were functionally assessed with QuickDASH questionnaires. One hundred patients and one hundred healthy subjects were included. Seventy-one percent of patients with NTOS were females with a mean age of 39.4 ± 9.6. They were compared to controls, 73% females and the mean age of 38.8 ± 9.8. Patients’ mean QuickDASH was 58.3 ± 13.9. Concerning the peak of strength at 60°/s, the symptomatic limbs of patients with NTOS had significantly 21% and 29% less strength than the control limbs for medial and lateral rotators, respectively (p ≤ 0.001). At 180°/s, the symptomatic limbs had significantly 23% and 20% less strength than the controls for medial and lateral rotators, respectively (p ≤ 0.001). The symptomatic limbs had significantly 45% and 30% less endurance than the controls for medial and lateral rotators, respectively (p ≤ 0.001). These deficits were correlated to the QuickDASH. Patients with NTOS presented a significant deficit of strength and endurance of the shoulder rotators correlated to disability. This highlights the interest in upper-limb strength evaluation in the diagnostic process and the follow-up of NTOS.