External Rotation Strength Research Articles

Lower trapezius tendon transfer for massive irreparable rotator cuff tears improves outcomes in patients with high grade fatty infiltration of teres minor

BackgroundThis study compares postoperative outcomes of lower trapezius tendon transfers (LTTT) in massive irreparable rotator cuff (RC) tears based on the degree of teres minor (TM) fatty infiltration. MethodsIn this prospective longitudinal observational study, patients with massive RC tears undergoing arthroscopic-assisted LTTT by two surgeons were screened. TM fatty infiltration on preoperative MRI was graded using the Goutallier classification. Two groups were created: Group A included Grades 0 and 1 (no or little fatty infiltration), and Group B included Grades 2 to 4 (moderate to severe fatty infiltration). Participants completed the SANE score preoperatively, and 12- and/or 24-months postoperative along with a clinical assessment. Independent t-tests compared groups, and paired t-tests compared pre- versus postoperative results. Significance was defined as p < 0.05. ResultsThere were 47 patients in Group A and 19 in Group B. No group differences were found in preoperative SANE score, forward elevation or active external rotation (ER). Both groups showed significant postoperative improvements in SANE score with no differences between groups. An ER lag sign was observed in 18/47 patients (38.3 %) in Group A and 11/19 patients (57.9%) in Group B (p=0.177). Preoperative ER strength was significantly different in Group A (2.9 kg) versus Group B (0.7 kg; p=0.001), but postoperative ER strength was similar (p=0.931). ConclusionLTTT is a suitable salvage procedure regardless of the degree of TM fatty infiltration and should be considered as an alterative procedure to latissimus dorsi tendon transfer in patients with high grade TM fatty infiltration.

The Effect of Lateralization on Clinical Outcomes after Anatomic Total Shoulder Arthroplasty

BackgroundLateralization has been previously studied for reverse shoulder arthroplasty, but there is little clinical research investigating the independent effect of medialization or lateralization of the joint line, nor global medialization or lateralization for anatomic total shoulder arthroplasty (TSA). The goal of this study was to assess the impact of lateralization on clinical outcomes after anatomic TSA. MethodsA retrospective review of a multi-institutional registry was performed. All anatomic TSAs with postoperative radiographs and minimum 2-year clinical outcomes were included. Six measurements were made on postoperative radiographs: (1) humeral COR shift from ideal, (2) acromion to glenoid distance (A-G), (3) glenoid to greater tuberosity distance (GT-G), (4) acromion to greater tuberosity distance (A-GT), (5) lateralization shoulder angle (LSA) and (6) critical shoulder angle (CSA). Linear regression analyses were performed to evaluate any associations between radiographic measures and PROs, range of motion (ROM) and strength. Results357 patients were included, mean age 65 years and 61% male. For PROs, the COR (p =0.002) was significantly associated with the ASES score. Additionally, COR was significantly associated with the WOOS score. For ROM, COR shift was the only radiographic measure with a significant association with forward flexion (p =0.002). Other significant associations with ROM in the regressions were: use of CT based preoperative planning (FF) and preoperative ROM. The A-G distance (p =0.008) and GT-G distance (p =0.002) were both significantly associated with external rotation strength. ConclusionsIncreasing humeral COR shift negatively impacts PROs and ROM after anatomic TSA regardless of the joint line position. Increased glenoid lateralization and increased global lateralization were associated with increased ER strength.

Relationships between upper trunk rotation kinematics and arm fatigue after repetitive pitching among baseball pitchers

ABSTRACT Early upper trunk rotation during baseball pitching has been associated with higher upper-limb kinetics. However, its relationship with arm fatigue after repetitive pitching is unclear. This study aimed to investigate associations between upper trunk rotation kinematics and arm fatigue. A total of 14 healthy male pitchers (age 27.1 ± . 9.0 yrs) threw 45 pitches across three innings. Pitching mechanics and ball velocity were assessed using 3-D motion analysis (Vicon, UK) and Rapsodo (Rapsodo, USA). Subjective arm fatigue was assessed by CR-10 Borg scale, whereas grip and shoulder external rotation strength were evaluated before and after pitching sessions. Ball velocity and the timing of upper trunk rotation did not change significantly throughout the three innings. Three-inning pitching produced significant levels of subjective and objective arm fatigue. The onset timing of upper trunk rotation (OTUTR) had significant effects on CR-10 Borg scale and ball velocity. The magnitude of effect of OTUTR on ball velocity may be clinically significant. These findings suggest that the timing of upper trunk rotation may not significantly affect arm fatigue with relatively low pitch counts, and early OTUTR may lead to early reduction in ball velocity.

Peak hip external rotation torque and single-rater reliability is influenced by measurement position in the ISOMED2000

Measurement of hip external rotation strength (ERS) is important for preventive and rehabilitative purposes. ERS can be measured in 3 different positions in the isokinetic dynamometer ISOMED2000. However, it is not clear whether these measurement positions effect ERS nor if these positions are reliable in the ISOMED2000. Hence, the purpose of this study was to compare ERS in these positions, the reliability and the agreement. A cross-sectional design was conducted to compare measurement positions and a test–retest design to assess intra-rater reliability and agreement. Twenty-four healthy, physically active athletes participated in the study. Peak isometric torque was measured in the ISOMED in prone, supine, and side-lying position across two sessions on one day. Differences between positions were evaluated with the Wilcoxon-signed-rank test and cliff’s delta. Reliability was assessed via intraclass correlation. Agreement was determined using the standard error of measurement (SEM), minimal detectable change (MDC), and Bland-Altman analysis (BAA). Results indicated a significant influence of measurement position on ERS (p < 0.001) with high effect sizes (>0.74). Reliability and agreement were high in all positions, but highest for the side-lying position (ICC = 0.90 [0.78, 0.96]; SEM = 0.08; MDC = 0.23; BAA_bias = 3.4 %, BAA_loA = 37 %). There were only poor to moderate correlations between measurement positions. These findings suggest that measurement position significantly affects ERS. Furthermore, the effect varies across individuals indicating that normative values cannot be used interchangeably or be adapted across positions. In diagnostic testing ERS should be measured in the same position, but preferably in the side-lying position.

"Surviving the dip" after subacromial balloon spacer implantation for massive rotator cuff tear treatment: a retrospective case series.

Subacromial balloon spacer implantation (SBSI) attempts to decrease glenohumeral joint (GHJ) pain and improve function in patients with an irreparable rotator cuff tear (RCT) and minimal osteoarthritis. Between 12 and 26 weeks post-SBSI, gradual implant resorption may create a "balloon dip" that decreases GHJ function and increases pain. This retrospective cohort study attempted to delineate shoulder function, active mobility, strength, pain, and functional task impairment during the "balloon dip" period. Sixty-five consecutive patients (55.9 ± 7years of age, 42 men) with an irreparable RCT treated by the same fellowship-trained shoulder surgeon participated in this study. Outcome measurements pre-SBSI, during Phase I (early pain control ≤ 3weeks post-SBSI), Phase II (early rehabilitation > 3-11weeks post-SBSI), Phase III (advanced rehabilitation-early balloon resorption > 11-16weeks post-SBSI), Phase IV (early strength training > 16-24weeks post-SBSI), and Phase V (advanced strength training > 24weeks post-SBSI) included the American Shoulder and Elbow Society (ASES) score for perceived bilateral shoulder function, visual analog scale (VAS) surgical shoulder pain score, active mobility, and shoulder manual muscle strength testing (p ≤ 0.05). The mean final follow-up time was 40weeks (range = 24.1-89.7weeks). The surgical shoulder had higher ASES scores at Phase V than pre-SBSI. Surgical shoulder pain was less during Phase V than pre-SBSI. The surgical shoulder had greater flexion during Phase V than at Phase II or pre-SBSI, and greater external rotation (adducted) during Phases V-III than pre-SBSI. Peak shoulder internal rotation to level 12 (thoracic spinous process #10) occurred during Phase V. Peak shoulder flexor, external rotator, and internal rotator strength occurred during Phase V. During Phase I, most subjects were unable to sleep on their surgical shoulder, wash their back/do up their bra, reach a high shelf, or lift 10-lbs overhead. Tasks that were impaired during the "balloon dip" (between Phase III and V) were lifting 10-lbs overhead, reaching a high shelf, and doing normal work. By the end of Phase V, however, most subjects could perform each task with minimal or no difficulty. Surgical shoulder function improved and pain decreased, however, specific perceived functional task impairments remained. During the "balloon dip" phase, the perceived ability to lift 10 lbs above shoulder level, to reach a high shelf, and to do usual work activities were the most impaired tasks.

Profiling Shoulder Strength in Youth Surfers: Implications for Injury Prevention and Performance Enhancement

The scapular region has the highest incidence of acute injuries in surfing. However, little is known about the shoulder strength profile in surfers. The aim of this research was to establish the profile of internal and external rotation strength in a group of youth surfing athletes. Methods: Isometric shoulder internal and external rotation strength was measured using a portable dynamometer in 41 (19 boys e 22 girls) youth surfing athletes (13.3 ± 2.1 years, 49.3 ± 9.8 kg, and 157.4 ± 9.5 cm). Regardless of gender, no significant differences were found between shoulder internal and external rotation strength. However, internal rotation strength was bilateral greater than external rotation strength. When comparing boys and girls, statistically significant differences were only found for the left-arm internal rotation strength when adjusted for body mass. Boys exhibited more strength than girls in all situations. No differences were observed based on the surfer's stance. The data from this research provides valuable information for coaches and trainers working with young surfers, allowing a deeper understanding of the specific shoulder strength profile, for a more effective development of training programs.

The effect of smoking on functional outcomes and implant survival of anatomical total shoulder arthroplasty.

We sought to compare functional outcomes and survival between non-smokers, former smokers, and current smokers who underwent anatomical total shoulder arthroplasty (aTSA) in a large cohort of patients. A retrospective review of a prospectively collected shoulder arthroplasty database was performed between August 1991 and September 2020 to identify patients who underwent primary aTSA. Patients were excluded for preoperative diagnoses of fracture, infection, or oncological disease. Three cohorts were created based on smoking status: non-smokers, former smokers, and current smokers. Outcome scores (American Shoulder and Elbow Surgeons (ASES), Constant-Murley score, Shoulder Pain and Disability Index (SPADI), Simple Shoulder Test (SST), University of California, Los Angeles activity scale (UCLA)), range of motion (external rotation (ER), forward elevation (FE), internal rotation, abduction), and shoulder strength (ER, FE) evaluated at two- to four-year follow-up were compared between cohorts. Evaluation of revision-free survival was performed using the Kaplan-Meier method to final follow-up. We included 428 primary aTSAs with a mean follow-up of 2.4 years (SD 0.6). Our cohort consisted of 251 non-smokers, 138 former smokers who quit a mean 21 years (SD 14) prior to surgery (25 pack-years (SD 22)), and 39 current smokers (23 pack-years (SD 20)). At two- to four-year follow-up, former smokers had less favourable SPADI, SST, and FE strength compared to non-smokers, and current smokers had less favourable SPADI, SST, ASES score, UCLA score, Constant-Murley score, FE, abduction, and ER strength compared to non-smokers. Non-smokers exhibited higher revision-free survival rates at two, five, eight, and ten years postoperatively compared to former smokers and current smokers, who had similar rates. Our study suggests that smoking has a negative effect on aTSA functional outcomes that may persist even after quitting.

Enhancing Acromioclavicular Rehabilitation and Functional Capacity With Blood Flow Restriction Training: A Case Report

BACKGROUND: Type V Acromioclavicular joint (ACJ) separations often require surgical stabilization to restore functional capacity of the shoulder. However, the purpose of this case study is to demonstrate nonsurgical management of this condition. CASE PRESENTATION: A 32-year-old female with a radiographic type V ACJ separation underwent nonsurgical management. This case used a novel criteria-based protocol, which utilized 6 weeks of upper extremity blood flow restriction to restore the functional capacity of a radiographic type V ACJ separation. OUTCOME AND FOLLOW-UP: Following nonsurgical management, there was a 2.47-fold increase in external rotation strength, 97% limb symmetry on upper quarter Y-Balance, a score of 91 on American Shoulder and Elbow Surgeons assessment, and a 9-mm radiographic reduction of the coracoclavicular interval. DISCUSSION: The case illustrates how clinical findings did match the radiographical findings, but the nonsurgical treatment using upper extremity blood flow restriction provided a desired functional outcome. JOSPT Cases 2024;4(4):185-199. Epub 29 October 2024. doi:10.2519/josptcases.2024.0031

Which muscle is the external rotation compensator after superior capsular reconstruction?

BackgroundSuperior capsular reconstruction (SCR) is a surgical option for massive irreparable rotator cuff tears, particularly involving the supraspinatus and infraspinatus. In this procedure, the torn infraspinatus is not repaired or reconstructed. However, an improvement in postoperative external rotation (ER) angle and strength is observed. There is a lack of studies explaining how ER is restored after SCR. The aim of this study is to identify the ER compensator by assessing the muscle volume of the posterior deltoid and teres minor. MethodsSixty-eight patients with massive rotator cuff tears underwent SCR during 2016-2021. Of these patients, 28 who met the following inclusion criteria were retrospectively reviewed: (1) massive rotator cuff tears including the supraspinatus and infraspinatus; (2) severe muscle atrophy and fatty change; (3) intact or reparable subscapularis tendon; (4) Hamada of grade 3 or lower. Posterior deltoid and teres minor volume were measured by using an open-source medical image processing software preoperatively and 1-year postoperatively. The percentage of the posterior deltoid and teres minor muscle volume change was compared between patients with 1-year postoperative ER manual motor testing (MMT) of grade 5 and of grade < 5. The relationship between grade of fatty change, percentage of the muscle volume change, and ER angle and strength were evaluated. ResultsThere was a significant increase in the 1-year postoperative teres minor volume compared with the preoperative volume (24.6±10.3 cm³ versus 20.9±8.3 cm³, p<0.000), while the posterior deltoid volume remained unchanged (178.1±48.3 cm³ versus 178.8±47 cm³). Patients with ER MMT of grade 5 had a greater teres minor volume compared to those with an ER MMT grade of less than 5 (22.3% versus 9.4%), although this difference was not significant (p=0.074, 95% CI=-1.3–27.0). The posterior deltoid volume showed no significant change. The percentage of teres minor volume change had a weak positive correlation with ER strength (r=0.308, p=0.055, 95% CI=-0.02–1.0). There was a significant negative correlation between ER strength and the severity of both preoperative and postoperative fatty changes in the teres minor (r=-0.258, p=0.065, 95% CI=-1.0–-0.042 and r=-0.323, p=0.028, 95% CI=-1.0–-0.113, respectively). The pre- and postoperative fatty changes in the teres minor were negatively correlated with the percentage of teres minor volume change (r=-0.298, p=0.062, 95% CI=-1.0–0.031 and r=-0.413, p=0.015, 95% CI=-1.0–-0.1, respectively). ConclusionThe teres minor may serve as a potential compensator for ER in patients with massive rotator cuff tears following SCR.

Hip Range of Motion and Strength in Young Pre-Professionals Ballet Dancers Versus Non-Dancers.

Introduction: Lower-extremity external rotation, commonly known as turnout, is a fundamental skill in dance. Limited data exist regarding joint range of motion and strength in pre-professional young dancers and non-dancers. This study aimed to evaluate the differences in hip range of motion and hip strength between pre-professional ballet dancers and non-dancers. Additionally, the study assessed the variations between the left and right sides within each group. Methods: This observational study assessed 60 pre-professional ballet dancers and 31 non-dancers with an average age of 11.91 ± 1.49. Evaluation included passive hip rotation, tibial torsion, total passive turnout measured with digital goniometers, and total active turnout (both static and dynamic) through standing on paper and rotational discs. Hip rotation strength was measured using a force sensor device. Statistical analyses encompassed student t-tests, Pearson's correlations, and ANCOVA with age and body weight as covariates, applying the Bonferroni correction for multiple comparisons. Results: Ballet dancers exhibited greater passive hip external rotation and lower passive hip internal rotation compared to non-dancers. They also demonstrated superior total active turnout (static and dynamic). After adjusting for age and weight, dancers demonstrated significantly higher hip external rotation strength than non-dancers. Hip internal rotation strength did not differ significantly between the groups. Ballet dancers displayed inherent asymmetry, with the left side showing greater tibial torsion and standing active turnout, while the right side exhibited greater hip external rotation during dynamic active turnout. Non-dancers did not show significant side differences. Conclusions: Young pre-professional ballet dancers exhibited significant hip rotation differences compared to non-dancers, including notable right-left asymmetry. These findings should be considered when planning training, aiming to optimize musculoskeletal attributes and promote balanced hip rotation. Recognizing these asymmetries and addressing muscular imbalances is vital for injury prevention and performance enhancement.

Isokinetic Strength and Balance Analyses for Predicting Return to Sports After the Latarjet Procedure: A Prospective Cross-sectional Study

Background: Isokinetic torque in shoulder internal rotation (IR) and external rotation (ER) can be considered as potential indicators for dynamic stability of the glenohumeral joint. Purpose: To assess the efficacy of 4-month isokinetic testing in predicting the 6-month return-to-sports (RTS) status after Latarjet surgery, explore its correlations with testing parameters, and identify optimal thresholds to ensure a safe RTS. Study Design: Cohort study; Level of evidence, 2. Methods: The study assessed athletes who underwent the Latarjet stabilization procedure between January 2022 and June 2023. The primary outcome was RTS at 6 months after surgery. The primary examined predictors were isokinetic testing metrics at 4 months postoperatively. Secondary outcomes comprised the modified Closed Kinetic Chain Upper Extremity Stability Test (mCKCUEST) and several patient-reported outcome measures, including the Walch-Duplay score, the Western Ontario Shoulder Instability Index (WOSI), and the Shoulder Instability–Return to Sports after Injury scale. To assess the predictors, patients were divided into those who returned to any level of sports compared with those who did not return to sports. The correlation between isokinetic testing results and other outcome scores was also analyzed. Results: A total of 71 patients (mean age, 27.43 ± 9.09 years) were included in the study. Of these, 23.61% did not return to sports, 38.89% returned at a lower level, and 37.50% returned to the same level. Significant rotational strength disparities were noted. Patients who did not return to sports at 6 months demonstrated inferior strength in concentric ER at 60 deg/s, concentric ER at 240 deg/s, concentric IR at 240 deg/s, and eccentric IR at 30 deg/s (P < .05). Similar trends appeared for all studied patient-reported outcome measures and the mCKCUEST (P < .05). Receiver operating characteristic analysis emphasized the significance of isokinetic testing in concentric ER at 240 deg/s (area under the curve = 0.759; P = .001; cutoff = 0.32 N·m/kg; sensitivity = 100.0%; specificity = 49.1%) and eccentric ER at 30 deg/s (area under the curve = 0.760; P = .001; cutoff = 0.51 N·m/kg; sensitivity = 94.1%; specificity = 49.1%) for RTS prediction. Additionally, ER strength moderately correlated with the Walch-Duplay score across all examined velocities (r = 0.26-0.34; P < .05). The modified WOSI score was weakly linked to ER strength at 240 deg/s and 30 deg/s (r = 0.24-0.25; P < .05) as well as moderately linked to the limb symmetry index in ER at 60 deg/s and 30 deg/s (r = 0.30-0.38; P < .05). Conclusion: Isokinetic testing can act as an independent predictor of successful RTS after Latarjet surgery, with concentric ER at 240 deg/s, concentric IR at 240 deg/s, eccentric ER at 30 deg/s, and eccentric IR at 30 deg/s showing the most accuracy. Strength recovery in ER was associated with better Walch-Duplay and modified WOSI scores.

Preoperative Nutrition Impacts Retear Rate After Arthroscopic Rotator Cuff Repair.

A rotator cuff retear following arthroscopic rotator cuff repair (ARCR) is a concern in older patients. However, only a few of its risk factors are amenable to preoperative intervention. We aimed to elucidate the relationship between preoperative nutritional status and rotator cuff retears after ARCR. This single-center retrospective study included patients aged ≥65 years with rotator cuff tears who underwent ARCR. The Geriatric Nutritional Risk Index (GNRI) was used to assess preoperative nutritional status. Data collection encompassed patient demographics, clinical assessments, and surgical specifics. Patients were divided into healed and retear groups based on 2-year post-ARCR magnetic resonance imaging results. Logistic regression analysis was conducted to adjust for confounding factors and detect independent risk factors for retears. The GNRI cutoff value for retear prediction was determined by a stratum-specific likelihood ratio; clinical outcomes were compared based on the cutoff values obtained. Overall, 143 patients were included. The retear rate was 20.3%. The albumin level, GNRI, postoperative shoulder strength of abduction and external rotation, and postoperative Japanese Orthopaedic Association and Constant scores in the retear group were significantly lower than those in the healed group. The logistic regression analysis showed that low risk of morbidity and mortality (compared with no risk) based on the GNRI (odds ratio [OR], 3.39) and medial-lateral tear size per mm (OR = 1.10) were independent risk factors for a retear 2 years after ARCR. Stratum-specific likelihood ratio analysis identified data-driven strata as GNRI < 103, 103 ≤ GNRI < 109, and GNRI ≥ 109. Univariate analysis showed that patients with GNRI < 103 had a significantly higher retear risk than those with 103 ≤ GNRI < 109 and those with GNRI ≥ 109. Logistic regression analysis showed that GNRI < 103 compared with 103 ≤ GNRI < 109 (OR = 3.88) and GNRI < 103 compared with GNRI ≥ 109 (OR = 5.62), along with the medial-lateral tear size per mm (OR = 1.10), were independent risk factors for a retear at 2 years after ARCR. When assessing the risk of a retear after ARCR, GNRI ≥ 103 may indicate good preoperative nutritional status. However, more data are essential to ascertain the importance of this finding. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Greater hip internal rotation range of motion is associated with increased dynamic knee valgus during jump landing, both before and after fatigue.

The aim of this study was to analyse sex-specific differences contributing to dynamic valgus in competitive soccer players before and after a standardised fatiguing protocol. Thirty-nine healthy female and male competitive soccer players (19 females and 20 males) were recruited for the purpose of this study. Bilateral medial knee displacement (MKD) was assessed during drop jump landings using a three-dimensional motion capture system before and after a standardised fatiguing protocol. In addition, all soccer players underwent clinical examinations, including rotational hip range of motion (ROM), isokinetic strength testing and magnetic resonance imaging (MRI) of the hip and knee. Sex-specific and fatigue-dependent differences were reported, and the influence of demographic, clinical and radiographic factors on MKD was analysed via multiple linear regression models. Compared with male soccer players, female soccer players demonstrated a tendency towards increased MKD during drop jump landings before (p = 0.09) and after the fatiguing protocol (p = 0.04). Sex-specific differences included increased hip internal rotation (IR) ROM, decreased hip external rotation (ER) strength and increased femoral torsion in females (all p < 0.002). According to the multiple linear regression models (stepwise method), increased hip IR ROM (90° of flexion) and the non-dominant leg remained the sole independent predictors of increased MKD during drop jump landings before (p < 0.01 and p = 0.02, respectively) and after fatigue (p < 0.01 and p < 0.01, respectively). An increase in hip IR ROM in females was linearly related to MKD after fatigue (R2 = 0.25; p < 0.01). Female soccer players exhibited increased dynamic valgus before and after fatigue, which is likely attributed to joint mobility, as well as muscular and anatomical differences, such as increased hip IR ROM, reduced hip ER strength and increased femoral torsion. In particular, females with increased hip IR ROM were more susceptible to effects of fatigue on MKD, which may increase their risk for anterior cruciate ligament injury. Level III.

Effect of improving asymmetry through self-myofascial release in adolescent soccer player with hypomobility syndrome hip: A randomized controlled trial.

Hypomobility syndrome (HMS), or limited hip range of motion (ROM), is often reported in adolescents who train heavily. This study was aimed to investigate the impact of traditional static stretching (STR) and self-myofascial release (MFR) in adolescents with HMS hip. This study was a randomized controlled trial. Adolescent athletes with HMS hip were grouped as 23 STR and 23 MFR. Foam rolling was employed as the training method for MFR. Both interventions were performed twice a day for 20 minutes in 6 weeks. The training was filmed and distributed via the mobile video. Self-assessed Copenhagen Hip & Groin Outcome Score, ROM, strength, and hop tests were measured before and after the interventions. The healthy side without limitations was designated as non-HMS (nHMS) and taken as reference value. The study participants had limitations in flexion (FLX), abduction (ABD), internal rotation (IR), and external rotation (ER). The ROM of STR group was recovered to nHMS level. The FLX and ABD of MFR group was also recovered, however the IR and ER had lower angles compared to nHMS. MFR FLX, ABD, ER strength, and single hop test were restored like that of nHMS, however STR group was substantially lower than nHMS despite the improvements. Both groups depicted lower pre-intervention Copenhagen Hip & Groin Outcome Score subscale activities daily living, sport, and physical activity compared to nHMS. Activities daily living and physical activity were improved to healthy levels after the intervention, however sport was lower than that of nHMS. Both STR and MFR had impact on hip mobility and hip self-assessment score. Furthermore, MFR had strength improvements in FLX, ABD, and ER. However, the improvements in MFR group regarding triples, crossover hops, and self-assessed sports were limited. Therefore, STR and MFR are effective in improving not only ROM but also muscle function asymmetry in HMS hip.

Superior Capsular Reconstruction Using an Acellular Dermal Xenograft or Allograft Improves Shoulder Function but Is Associated with a High Graft Failure Rate.

Objectives: The purpose of the present study was to evaluate clinical and functional outcomes, graft integrity rate and progression of osteoarthritis after superior capsular reconstruction (SCR) at short-term follow-up. Methods: Consecutive patients that underwent SCR using an acellular dermal xeno- or allograft between May 2018 and June 2020 for the treatment of irreparable posterosuperior rotator cuff tears were included. Shoulder function (American Shoulder and Elbow Surgeons [ASES] score), pain (Visual Analog Scale [VAS] for pain) and active shoulder range of motion (ROM) were evaluated preoperatively and after a minimum of 24 months postoperatively. Isometric strength was measured at follow-up and compared to the contralateral side. Magnetic resonance imaging was performed to evaluate graft integrity and osteoarthritis progression (shoulder osteoarthritis severity [SOAS] score). Results: Twenty-two patients that underwent SCR using a xeno- (n = 9) or allograft (n = 13) were evaluated 33.1 ± 7.2 months postoperatively. Four patients in the xenograft group underwent revision surgery due to pain and range of motion limitations and were excluded from further analysis (revision rate: 18.2%). Shoulder function (ASES score: 41.6 ± 18.8 to 72.9 ± 18.6, p < 0.001), pain levels (VAS for pain: 5.8 ± 2.5 to 1.8 ± 2.0, p < 0.001) and active flexion (p < 0.001) as well as abduction ROM (p < 0.001) improved significantly from pre- to postoperatively. Active external rotation ROM did not improve significantly (p = 0.924). Isometric flexion (p < 0.001), abduction (p < 0.001) and external rotation strength (p = 0.015) were significantly lower in the operated shoulder compared to the non-operated shoulder. Ten shoulders demonstrated a graft tear at the glenoid (n = 8, 44.4%) or humerus (n = 2, 11.1%). Graft lysis was observed in seven shoulders (38.9%). The graft was intact in one shoulder (5.6%), which was an allograft. A significant progression of shoulder osteoarthritis was observed at follow-up (SOAS score: 42.4 ± 10.1 to 54.6 ± 8.4, p < 0.001). Conclusions: At short-term follow-up, SCR using an acellular dermal xeno- or allograft resulted in improved shoulder function and pain with limitations in active external rotation ROM and isometric strength. Graft failure rates were high and osteoarthritis progressed significantly. Level of Evidence: Retrospective cohort study, Level III.

Understanding musculoskeletal disorders in dancers: The role of lumbopelvic muscles and movement competency

ObjectiveTo investigate whether transversus abdominis activation (TrA), hip strength, and movement competency are associated with the incidence of musculoskeletal disorder episodes (MDEs) in dancers when controlling for confounding variables. The secondary objectives were to determine if there were differences between professional and preprofessional dancers for the aforementioned factors, as well as to determine if there were differences in TrA activation and hip strength between the dominant and non-dominant sides. DesignProspective cohort study. Methods118 dancers were recruited. The independent variables were collected at the beginning of the dance season: 1) TrA activation, 2) hip strength, and 3) movement competency. To assess the development of MDEs, a weekly electronic diary was used over a 38-week period. MDEs were compiled for each dancer's whole body and subdivided into total musculoskeletal disorder episodes (all body parts) and lower quadrant musculoskeletal disorder episodes (lower limb and lower back). ResultsLower TrA, as well as higher hip abductor and external rotator strength, were associated with a lower incidence of MDEs. TrA activation (β = 0.260, p = 0.023) and hip external rotator strength (β = −0.537, p = 0.002) could significantly explain 25.4% of the variance of total MDEs, as well as 20.9% of the variance of lower quadrant musculoskeletal disorder episodes (β = 0.272, p = 0.016; β = −0.459, p = 0.011). No significant associations were found between movement competency and MDEs. ConclusionsHigher hip strength could be a protective factor for MDEs among dancers. Further studies are needed to better understand the involvement of the transversus abdominis in MDEs.

Latissimus dorsi transfer or lower trapezius transfer: a treatment algorithm for irreparable posterosuperior rotator cuff tears muscles transfers in posterosuperior rotator cuff tears

IntroductionTendon transfers of the latissimus dorsi (LDT) or the lower trapezius (LTT) are treatment options for irreparable posterosuperior rotator cuff tears (PSIRCT). There is still no consensus on which type of tendon transfer is superior in the treatment of PSIRCT. Due to the differences in the anatomy and biomechanics, we hypothesize that there are different clinical situations in which either LDT or LTT should be preferred. The aim of this study was to evaluate the clinical and radiological outcomes of LDT and LTT in patients with PSIRCT to establish a clinical algorithm for the treatment decision. Materials and MethodsThis is a retrospective, single center observational study. Included were patients who underwent arthroscopically assisted LDT (aaLDT) or arthroscopically assisted LTT (aaLTT) for PSIRCT. In all patients, range of motion (ROM), external rotation strength, Visual Analogue Scale of Pain (VAS) and Subjective Shoulder Value (SSV) were determined pre- and postoperatively. Constant-Murley Score (CS) was evaluated at final follow-up. Complication rate, failure of the tendon transfer and revision rate were analyzed. ResultsIn total, 29 aaLDT (age 64 years, median follow-up time 45 months) and 8 aaLTT (age 54 years, median follow-up time 34 months) were included. Active ROM, VAS and SSV was significantly improved in both cohorts. At follow-up, the median CS was 73 (aaLDT) and 77 (aaLTT), respectively. Failure rate including revision surgery was 14% (aaLDT) and 13% (aaLTT), respectively. Low functional findings preoperatively were correlated to a lower functional outcome at follow-up in both groups. Painful loss of anterior elevation (PLEA) and loss of ER had no significant impact on functional outcomes in aaLDT. ConclusionFollowing the treatment algorithm based on the clinical examination, clinical outcome parameters, active ROM and pain could be significantly improved. Good preoperative function was associated with a good clinical outcome in both transfers. A low failure and revision rate supports the good decision-making of the algorithm presented.

Isometric Shoulder and Hip Strength Impact on Throwing Velocity and Reactive Strength.

The aim of the study is to examine relationships between shoulder extension-flexion and internal-external rotation strength of professional male handball players with throwing velocity, and the hip extension-flexion strength with horizontal and vertical reactive strength index. Fifteen professional male handball players participating in 1st League matches took part in the study. The results showed that isometric shoulder flexion and extension strength significantly predicted stable throwing velocity (r2=between 0.27-0.73) and dynamic throwing velocity (r2=between 0.30-0.62). In addition, isometric internal and external rotation strength significantly predicted stable throwing velocity (r2=between 0.32-0.54) and dynamic throwing velocity (r2=between 0.31-0.44). Moreover, isometric hip extension and flexion strength significantly predicted vertical reactive strength index (r2=between 0.31-0.45) and horizontal reactive strength index (r2=between 0.26-0.42). In conclusion, it was observed that shoulder strength has an enhancing effect on handball players' throwing velocity, while hip strength is a determining factor for the reactive strength index. In this context, it is assumed that shoulder weakness during throwing will affect the accuracy and velocity of throwing by disrupting the angular momentum, while weakness in the hip during the jump phase of the throwing motion will negatively affect the explosive power by limiting stabilization during landing.

Can acute mobilization and oscillation training profit on the joint position sense and strength of the rotator cuff muscles in young tennis players?

The rotator cuff is a group of muscles and tendons that act to stabilize the human shoulder and allow for its extensive range of motion. This study aimed to compare the immediate effect and durability of mobilization and oscillation dumbbell (OD) training on the Joint Position Sense (JPS) and strength of rotator cuff muscles in young tennis players. Twenty-six tennis players were divided into two experimental groups. G1 only performed mobilization techniques while G2 only performed OD training, before, after and after one week of the protocols, the strength and JPS of the shoulder joint were measured with an isokinetic dynamometer. Repeated analysis of variance (RMANOVA) and Bonferroni post hoc test were used to examine the differences between the groups. The analysis of covariance was used to examine the differences between the groups. In general, the results showed a significant effect of both mobilization techniques and OD training programs on the JPS and internal and external rotation strength of young tennis players, but only one difference was observed between the two in external rotation for the eccentric/concentric action at 120°/sec (p=0009; ƞ2p= 0.32). Moreover, the main findings showed that mobilization techniques and OD improved internal and external rotations after the protocol and after one week when compared with baseline for the concentric/concentric and eccentric/concentric at 60°/sec and 120°/sec (p &lt; 0.05) with only one exception for the internal rotation concentric/concentric at 120°/sec for both groups (p &gt; 0.05). Based on this, it seems that in healthy tennis players, both one-session mobilization techniques and OD training can be used to improve JPS and strength. Keywords: Shoulder, Isokinetic, Torque, Resistance, Rotator cuff.

Trunk and shoulder strength and mobility in young female volleyball and handball athletes

IntroductionVolleyball and handball have typical overhead throwing motion that can generate adaptations in the athlete's kinetic chain predisposing to injuries and pain. Considering the importance of the trunk and shoulder in overhead throwing motion and the particularities of these action in different sports, this study aimed to compare the trunk and shoulder muscle strength and mobility in young female volleyball and handball athletes. DesignCross-sectional study with 70 female volleyball and handball athletes between 13 and 18 years old. MethodsShoulder rotators, trunk extension and flexion with rotation strength was measured with a handheld dynamometer (MicroFET 2, Hoogan Health Industries, West Jordan, UT, USA). Shoulder and trunk range of motion was measured with a digital inclinometer (Acummar – model ACU001). Total range of motion deficit (TROM deficit), glenohumeral internal and external rotation of dominant (DOM) and non-dominant (NDOM) shoulder were also calculated. ResultsHandball athletes presented greater muscle strength of trunk flexors/rotators (DOM: 24.96%, effect size: 0.687; NDOM, 31.83%, effect size: 0.798) and dominant shoulder internal rotators (16.65%, effect size: 0.619). The groups showed no difference for trunk and shoulder range of motion and external rotators strength. A TROM (volleyball: 48%, handball: 35%) and a glenohumeral internal rotation deficit (volleyball: 28%, handball: 29%) was found in both groups. ConclusionsYoung female handball athletes have greater strength of trunk flexors/rotators and dominant shoulder internal rotators compared to volleyball athletes. These differences may be related to the different demands required in the movement of these sports.