Glenohumeral and Hip Range-of-Motion and Strength Measures in Youth Baseball Athletes

Normative Hip Range of Motion and Strength Profiles of Uninjured Baseball Athletes: A Systematic Review

CONTEXT

The baseball athlete incorporates the use of the entire kinetic chain while throwing. Hip range of motion (ROM) and strength have been previously studied in its relation to injury development. It is a clinical necessity to understand the normative profiles of hip musculoskeletal function across the playing career.

OBJECTIVES

To identify the normative hip ROM and strength profiles of baseball players across level of play.

EVIDENCE ACQUISITION

The researchers searched the electronic databases MEDLINE, SPORTDiscus, CINAHL, and Embase using a custom search strategy. After applying inclusion and exclusion criteria, 31 articles were reviewed. Of these 31 articles, 22 examined hip ROM and/or strength in uninjured baseball athletes. A manual search of the references of those 22 articles revealed 4 additional articles that met the inclusion criteria. In total, 26 articles were included in data collection.

EVIDENCE SYNTHESIS

Articles were assessed for quality using the appraisal tool for cross-sectional studies. The appropriate hip ROM and strength data, along with player demographics, were extracted and reviewed to ensure accuracy. Articles were also categorized based on level of play and player position.

CONCLUSIONS

Hip ROM and strength profiles of baseball athletes across all levels of play were identified and presented to comprehensively summarize the available data on normative musculoskeletal hip profiles. Observed differences between positions and across levels of play were documented. In general, hip external rotation ROM was greater than internal rotation across all levels and between the stance and lead limbs. As age and level of play increased, the difference between hip external rotation and internal rotation ROM also increased. Hip strength increased as level of play (and subsequently age) increased. These summarized data can be used as benchmarks to compare clinical populations.

Differences in shoulder function among badminton players broken down by age and sex

BACKGROUND

Improving the understanding of shoulder function for badminton players would develop injury preventive programs. However, no studies on shoulder function reference parameters of badminton players when controlling for age and sex have been found.

OBJECTIVES

To examine the differences in shoulder function between elementary school-age badminton players and university badminton players using shoulder range of motion.

DESIGN

Cross-sectional study.

SETTING

Testing at elementary school and university.

PARTICIPANTS

67 players (7-12 year-old players and 18-22 year-old players) without shoulder injury experience.

MAIN OUTCOME MEASURES

Shoulder range of motion (ROM) included internal rotation (IR), external rotation (ER), and total ROM (TROM).

RESULTS

Significant differences in shoulder IR of both sides (dominant: 97.67° vs 77.78°, p < 0.001; nondominant:104.70° vs 88.89°, p < 0.001), dominant ER (126.30° vs 115.98°, p = 0.013), TROM of both sides (dominant: 222.97° vs 193.76°, p < 0.001; nondominant: 222.90° vs 200.10°, p = 0.001), and TROM loss (-0.06° vs 6.34°, p = 0.047) existed between elementary school-age and university players. Significant differences in IR of both sides existed between male elementary school-age and university players (dominant: 98.38° vs 72.50°, p < 0.001; nondominant: 106.72° vs 83.99°, p < 0.001) as well as in female players (dominant: 95.25° vs 82.84°, p = 0.007; nondominant: 103.01° vs 93.57°, p = 0.035). Additionally, significant differences in IR of both sides (dominant: 72.50° vs 82.84°, p = 0.016; nondominant: 83.99° vs 93.57°, p = 0.012) and TROM of both sides (dominant: 188.24° vs 199.05°, p = 0.025; nondominant: 192.43° vs 207.44°, p = 0.002) existed between male and female university players.

CONCLUSIONS

Compared with university badminton players, elementary school-age badminton players showed significantly greater shoulder IR and TROM of both sides and dominant ER while significantly smaller TROM loss. However, regardless of sex, no significant differences of bilateral deficit for glenohumeral rotation existed between elementary school-age and university badminton players.

Evaluation of Hip Characteristics in Baseball and Softball Athletes with and Without Throwing Arm Pain

During throwing, the lower extremity assists in the generation and transfer of momentum. Lower extremity stability assists in this transfer by providing a base for distal mobility of the arm segments. This study aimed to determine differences between hip rotational range of motion and strength based on the presence of throwing-arm pain (yes/no) and throwing sport (baseball/softball). We hypothesized those experiencing pain would display decreases in hip range of motion and strength, and that softball players would display greater range of motion than baseball, but less strength based on sex-specific characteristics. Forty-four baseball (13±2 years, 165.2±13.0 cm, 58.5±13.4 kg) and 50 softball players (13±2 years, 160.9±11.2 cm, 62.7±17.9 kg) participated. Multivariate analysis of variance tests (2×2) determined differences in bilateral hip range of motion, total arc of motion, and strength between pain status and sport. There were no significant interactions (>0.05) for pain status and sport on hip range of motion, total arc of motion, and strength. Furthermore, no significant main effects (>0.05) were found for pain status or sport alone on range of motion or strength. Future work should be directed at explaining the effects of hip characteristics on the throwing motion and how it equates to throwing-arm health.

A Field-expedient Arm Care Screening Tool Can Identify Musculoskeletal Risk Factors in Baseball Players

BACKGROUND

Preseason movement screening can identify modifiable risk factors, deterioration of function, and potential for injury in baseball players. Limited resources and time prevent high school baseball coaches from performing movement screens on their players.

HYPOTHESIS

The arm care screen (ACS) will be highly sensitive to detecting musculoskeletal risk factors.

STUDY DESIGN

Cross-sectional.

LEVEL OF EVIDENCE

Level 3.

METHODS

A total of 150 baseball players were independently scored on the ACS electronically by reviewing a video recording of each player's screening performance. Discriminability of the ACS was determined with a 2 × 2 contingency table dichotomizing musculoskeletal risk factors as present or absent based on a predetermined cutoff value and those who passed or failed the corresponding ACS subtest.

RESULTS

High sensitivity was observed on the reciprocal shoulder mobility (0.89; 95% CI 0.81-0.94), 90/90 total body rotation (0.86; 95% CI 0.79-0.92), and lower body diagonal reach (0.85; 95% CI 0.78-0.91) tests of the ACS suggesting sufficient ability to identify musculoskeletal impairments and risk factors.

CONCLUSION

The ACS is a simplistic screening tool that the coach can administer to discriminate between youth, high school, and college-level baseball players who possess musculoskeletal risk factors. The ACS subtests demonstrated high sensitivity for correctly identifying musculoskeletal risk factors common in baseball players and can be useful as a screening tool for baseball coaches developing arm care exercise programs.

CLINICAL RELEVANCE

A field-expedient screen could provide coaches the ability to identify musculoskeletal risk factors that need to be addressed to minimize injury risk factors in a time-efficient manner.

Is there an association between joint range of motion and muscle strength in young female dancers? And, does it depend on the effects of age and menarche?

Aiming to determine the association between joint range of motion (ROM) and muscle strength; and, the effect of age and menarche on those two factors; 132 pre-and post-menarche dancers, aged 12-14 years were assessed for joint ROM and for muscle strength at the hip, knee and ankle and foot joints. En-pointe ROM was significantly correlated with ankle plantar-flexors' (r = -.184) and with ankle dorsiflexors' muscle strength (r = -.221). Hip external rotation ROM was significantly correlated with knee extensors' strength (r = -.263). Pre-menarche dancers had higher joint ROM compared with post-menarche dancers; yet, dancers at post-menarche were stronger compared to dancers at pre-menarche. The slope coefficient was negative at the age of 12 in hip external rotation and in en-pointe (-0.80 and -0.52, respectively) and became steeper with age (age 13: -3.52 and -3.28, respectively; age 14: -6.31 and -4.42, respectively). Along maturation, dancers with high joints ROM showed reduced muscle strength. Pre-menarche dancers have higher joint ROM, yet reduced muscle strength, compared with post-menarche dancers. As the association between joint ROM and muscle strength might be involved with growth and development, young dancers should be screened along pubertal stages in order to decide the correct curricula and to prevent future injuries.

Relationship Between Posterior Shoulder Tightness and Lower-Limb Flexibility in College Baseball Players

CONTEXT

Posterior shoulder tightness evaluated as limited glenohumeral internal rotation and horizontal adduction is a risk factor for throwing-related shoulder and elbow injuries. Given that the throwing motion uses the entire body kinematics, limited lower-limb flexibility might be associated with posterior shoulder tightness. Therefore, we aimed to investigate the relationships between posterior shoulder tightness and lower-limb flexibility in college baseball players.

DESIGN

Cross-sectional study.

SETTING

University laboratory.

PARTICIPANTS

Twenty-two college baseball players (20 right-handed and 2 left-handed).

METHODS

To investigate the relationships between glenohumeral range of motion and lower-limb flexibility using simple linear regression analysis, we measured passive range of motion of glenohumeral internal rotation and horizontal adduction, hip internal/external rotation in the prone/sitting position, ankle dorsiflexion, and quadriceps and hamstrings flexibility from both shoulders and legs.

RESULTS

Our analysis indicated that decreases in the lead leg hip external rotation in the prone position were moderately associated with limitations in glenohumeral internal rotation (R2 = .250, β [95% confidence interval, CI] = 0.500 [0.149 to 1.392], P = .018) and horizontal adduction (R2 = .200, β [95% CI] = 0.447 [0.051 to 1.499], P = .019) on the throwing shoulder. Furthermore, there were significant moderate relationships between decreases in glenohumeral internal rotation and limited lead leg quadriceps flexibility (R2 = .189, β [95% CI] = 0.435 [0.019 to 1.137], P = .022), and between decreases in glenohumeral horizontal adduction and limited stance leg ankle dorsiflexion (R2 = .243, β [95% CI] = 0.493 [0.139 to 1.438], P = .010).

CONCLUSION

College baseball players with limited lower-limb flexibilities including the lead leg hip external rotation in the prone position, the lead leg quadriceps flexibility, and the stance leg ankle dorsiflexion showed excessive posterior shoulder tightness. The current results support the hypothesis that lower-limb flexibility is associated with posterior shoulder tightness in college baseball players.

An Investigation of Bilateral Symmetry in Softball Pitchers According to Body Composition

Introduction

High body fat percentage (bf%) is considered a potential injury risk factor for softball pitchers amidst the already high rates of pitching-related injury. Similarly, research points out that large bilateral asymmetries are another risk factor for softball pitchers. As softball pitching is a highly asymmetric sport and the repetitive nature of the windmill pitch places high stress on the body while pitchers are in unbalanced and asymmetric positions, research examining body composition and asymmetry is necessary.

Purpose

The purpose of this study was to compare functional characteristics of softball pitchers with a healthy and a high bf%. Bilateral symmetry was assessed for pitchers' hip and shoulder isometric strength (ISO) and range of motion (ROM) between the following two groups of softball pitchers: (1) those with a high bf% (≥32%) and (2) those with a healthy bf% (<32%).

Methods

A total of 41 high school female softball pitchers from the southern United States agreed to participate (1.69 ± 0.07 m, 76.14 ± 17.08 kg, 15.1 ± 1.1 years). Pitchers completed a dual-energy X-ray absorptiometry (DEXA) scan and were grouped into one of the following two categories based on their bf%: healthy (<32 bf%) and high (≥32 bf%). Bilateral symmetry was assessed for pitchers' hip and shoulder ISO and ROM using a handheld dynamometer and inclinometer, respectively. Bilateral arm bone and lean mass was also measured via the DEXA.

Results

Mixed analyses of variance revealed a significant interaction between bf% groups and side dominance for internal rotation shoulder ROM, F_{(1, 39)} = 14.383, p < 0.001, η²_p = 0.269. Main effects for side dominance were also observed for shoulder external rotation ISO, F_{(1, 39)} = 8.133, p = 0.007, η²_p = 0.173, hip internal rotation ISO, F_{(1, 39)} = 4.635, p = 0.038, η²_p = 0.106, arm bone mass, F_{(1, 39)} = 38.620, p < 0.001, η²_p = 0.498, and arm lean mass, F_{(1, 39)} = 101.869, p < 0.001, η²_p = 0.723.

Conclusion

Asymmetries and slight differences in functional characteristics exist between bf% groups. Altered functional characteristics may influence pitchers' windmill pitch movement and should be acknowledged by support staff to improve softball pitchers' health and longevity.

Implications

Insight into asymmetries can help researchers and clinicians understand the implication of excess body fat and further theorize mechanisms of injury among this athlete population.

Supraspinatus Tendon Changes and Glenohumeral Range of Motion in College Baseball Players

Baseball players commonly show altered glenohumeral range of motion during internal rotation, external rotation, total rotation, and horizontal adduction. These altered ranges of motion appear to be associated with throwing shoulder injuries, which frequently involve the supraspinatus tendons; thus, we aimed to examine the relationship between altered glenohumeral range of motion and supraspinatus tendon changes in collegiate baseball players. To investigate this association using the Pearson correlation coefficient, we measured glenohumeral internal rotation, external rotation, total rotation, and horizontal adduction ranges of motion and supraspinatus tendon thickness in 22 college baseball players. Consequently, there was a significant relationship between increase in supraspinatus tendon thickness and greater deficit of internal rotation (r=-0.520, P=0.013). Increased supraspinatus tendon thickness tended to be associated with greater external rotation gain (r=0.394, P=0.073). No other range of motion had any relationship with supraspinatus tendon changes. These results might indicate that restricted glenohumeral internal rotation and excessive gain in external rotation increase the risk of supraspinatus tendon abnormalities in baseball players.

Cross-sectional Study of the Hip Joint Condition in Young Baseball Players

Objective

The hip joint is a crucial part of the kinetic chain for throwing baseball pitches. Nevertheless, few reports have described assessments of the functional development of the hip joint in young baseball players.

Methods

We examined 315 young baseball players, 7-14 years old, all of whom had completed a self-administered questionnaire including items related to the dominant side and throwing-related hip joint pain sustained during the previous year. We measured the hip ranges of motion (ROMs: external and internal rotation and flexion) and hip muscle strengths (external and internal rotation) on the dominant and non-dominant sides. The differences of hip ROMs and muscle strengths between the dominant and non-dominant sides and between age groups were investigated. Correlations were calculated between the players ages and hip ROMs and muscle strengths.

Results

No baseball player reported hip pain. The hip external rotation on the dominant side was smaller than that on the non-dominant side, whereas the hip internal rotation on the dominant side was greater than that on the non-dominant side. However, no significant difference was found between the dominant and non-dominant sides in terms of the hip muscle strength. Significant positive associations were found between the player's age and hip muscle strengths, whereas significant negative associations were found between the age and hip ROMs.

Conclusions

Our data concerning the relationship between age and hip joint development could be useful for supporting strategies for the prevention and rehabilitation of throwing injuries; however, hip injuries might be rare among young baseball players.

Hip Range of Motion and Strength and Energy Flow During Windmill Softball Pitching

CONTEXT

Inadequate hip range of motion (ROM) and isometric strength (ISO) may interfere with energy flow through the kinetic chain and result in increased injury susceptibility.

OBJECTIVE

To examine the relationship of hip ROM and ISO with energy flow through the trunk and pitching-arm segments during the windmill softball pitch in youth athletes. A subsequent purpose was to examine the relationship between energy flow and pitch speed.

DESIGN

Descriptive laboratory study.

SETTING

University research laboratory.

PATIENTS OR OTHER PARTICIPANTS

A sample of 29 youth softball pitchers (age = 11.2 ± 1.3 years, height = 155.0 ± 10.4 cm, mass = 53.2 ± 12.6 kg).

MAIN OUTCOME MEASURE(S)

Bilateral hip internal-rotation and external-rotation (ER) ROM and ISO were measured. Net energy outflow and peak rates of energy outflow from the distal ends of the trunk, humerus, and forearm were calculated for the acceleration phase of the windmill softball pitch, and pitch speed was measured.

RESULTS

Regression analysis revealed an effect of drive-hip ER ISO on the net energy flow out of the distal ends of the trunk (P = .045) and humerus (P = .002). Specifically, increased drive-hip ER ISO was associated with increased net energy outflow from the trunk to the humerus and from the humerus to the forearm. No significant effects of hip ROM or other hip ISO measures were observed. Additionally, pitchers who achieved higher peak rates of distal outflow tended to achieve higher pitch speeds.

CONCLUSIONS

An association was present between drive-hip ER ISO and the net energy flow out of the distal ends of the trunk and humerus during the acceleration phase of the windmill softball pitch, emphasizing the importance of hip and lower body strength in executing the whole-body windmill pitch. Overall, energy-flow analysis is an interesting new way to analyze pitching mechanics and will aid in furthering our understanding of performance and injury risk in windmill softball pitching.

The Effects of Body Mass Index on Softball Pitchers' Hip and Shoulder Range of Motion

Currently it is hypothesized that increased body mass index may contribute to overuse injuries. Thus, if hip or shoulder range of motion is affected by body mass index, pitchers may be placing additional stress on joints as they seek to pitch at maximal velocity. The purpose of this study was to examine if range of motion at the hips and shoulders were related to body mass index classification. A sample of 147 female softball pitchers (17.0±4.2 years; 167.6±11.8 cm; 70.6±17.5 kg; body mass index=24.8±4.7 kg/m ² ) participated. Bilateral hip and shoulder range of motion were assessed. Multivariate analysis of variance results indicated body mass index [Wilks’ Λ =0.742, F=1.722, p=0.014, η ² =0.095] significantly affected range of motion of the shoulder and hip. Post hoc results indicated the underweight group had significantly more range of motion than the obese group in hip internal range of motion on both the throwing side (mean difference=12.39, p=0.005) and glove side (mean difference=11.98, p=0.004). Although body composition is not overly emphasized among softball pitchers, the current study reveals excess weight may inhibit proper mechanics. Coaches, athletic trainers, strength and conditioning personnel, and athletes should acknowledge the role that body composition can play in affecting pitch outcomes.

Hip internal and external rotation range of motion reliability in youth baseball players

BACKGROUND

Impaired hip range of motion has been related to increased injury risk in baseball players. However, no hip rotation range of motion (ROM) reliability studies have been performed in youth, which cannot be assumed to be comparable to adults. This study aimed to: 1) assess the inter- and intra-rater reliability of hip rotation passive ROM in youth baseball players; 2) calculate the standard error of measurement (SEM) and minimum clinically important difference (MCID).

METHODS

Hip external (ER) and internal (IR) rotation were measured. Inter and intra-rater reliability were assessed through intraclass correlation coefficients (ICC) and 95% Confidence interval (95% CI), with SEM and MCID. Bland-Altman plots were used to assess overall measurement bias.

RESULTS

Nineteen youth baseball players participated. Hip ER intra-rater ICC was excellent (tester one: 0.983 (0.965, 0.993); tester two: 0.952 (0.903, 0.980) and hip IR was excellent (tester one: 0.965 (0.927, 0.985); tester two: 0.965 (95%CI: 0.928, 0.985). Hip ER SEM was 3.2 degrees, and hip IR was 2.2 degrees. Hip ER MCID was 7.5 degrees, and hip IR was 5.1 degrees. Bland-Altman plots for hip ER and IR did not detect any bias.

CONCLUSIONS

Hip ROM inter-rater and intra-rater reliability was excellent for use in youth baseball players, with no rater bias. Sports medicine professionals can reliably assess supine hip rotation ROM in youth baseball players. This ROM methodology can be easily administered within the clinic or pitch-side, and interpret the results, increasing its real-world applicability.

Preseason shoulder range of motion screening and in-season risk of shoulder and elbow injuries in overhead athletes: systematic review and meta-analysis

Objective

To characterise whether preseason screening of shoulder range of motion (ROM) is associated with the risk of shoulder and elbow injuries in overhead athletes.

Design

Systematic review and meta-analysis.

Data sources

Six electronic databases up to 22 September 2018.

Eligibility criteria

Inclusion criteria were (1) overhead athletes from Olympic or college sports, (2) preseason measures of shoulder ROM, (3) tracked in-season injuries at the shoulder and elbow, and (4) prospective cohort design. Exclusion criteria were (1) included contact injuries, (2) lower extremity, spine and hand injuries, and (3) full report not published in English.

Results

Fifteen studies were identified, and they included 3314 overhead athletes (baseball (74.6%), softball (3.1%), handball (16.1%), tennis (2.0%), volleyball (2.0%) and swimming (2.2%)). Female athletes are unrepresented (12% of the overall sample). Study quality ranged from 11 to 18 points on a modified Downs and Black checklist (maximum score 21, better quality). In one study, swimmers with low (<93°) or high (>100°) shoulder external rotation were at higher risk of injuries. Using data pooled from three studies of professional baseball pitchers, we showed in the meta-analysis that shoulder external rotation insufficiency (throwing arm <5° greater than the non-throwing arm) was associated with injury (odds ratio=1.90, 95% confidence interval 1.24 to 2.92, p<0.01).

Conclusion

Preseason screening of shoulder external rotation ROM may identify professional baseball pitchers and swimmers at risk of injury. Shoulder ROM screening may not be effective to identify handball, softball, volleyball and tennis players at risk of injuries. The results of this systematic review and meta-analysis should be interpreted with caution due to the limited number of studies and their high degree of heterogeneity.

PROSPERO registration number

CRD42017072895.

NO DIFFERENCES IN HIP RANGE OF MOTION EXISTS BETWEEN BASEBALL PLAYERS WITH AN ULNAR COLLATERAL LIGAMENT TEAR AND HEALTHY BASEBALL PLAYERS

BACKGROUND AND PURPOSE

Restrictions in hip rotational motion of the baseball athlete can alter throwing mechanics in a manner that is inefficient and increases risk of injury. The purpose of this study was to assess for differences in hip external rotation (ER) and internal rotation (IR) range of motion (ROM) between baseball players with an ulnar collateral ligament (UCL) tear and healthy baseball players.

DESIGN

Case-control.

METHODS

Eighty-seven baseball players with a UCL tear (UCL) were compared with 87 age, experience, and position-matched healthy baseball players (CONT). UCL were enrolled at the initial visit to the outpatient sports medicine facility while CONT were measured before their baseball season. Passive hip ROM (ER and IR) of the stance and lead limbs was measured in the prone position using a bubble goniometer. Hip total range of motion (TRM) was calculated by adding ER and IR of each limb. Independent t-tests were run to compare mean group differences for hip ROM (p<0.05).

RESULTS

No differences between groups were discovered for hip ER on the stance (UCL = 33.9 °±9.9 °, CONT = 34.3 °±10.6 °, p = 0.8) or lead (UCL = 32.9 °±9.9 °, CONT = 34.4 °±10.0 °, p = 0.3) limbs. Similarly, there were no group differences in hip IR on the stance (UCL = 30.6 °±10.5 °, CONT = 29.6 °±9.5 °, p = 0.5) or lead (UCL = 33.5 °±17.5 °, CONT = 29.5 °±9.0 °, p = 0.1) limbs. The groups were also similar in hip TRM on the stance (UCL = 64.5 °±13.7 °, CONT = 64.0 °±17.2 °, p = 0.8) and lead (UCL = 66.4 °±17.4 °, CONT = 63.9 °±15.6 °, p = 0.3) limbs.

CONCLUSIONS

When measured in the prone position, hip passive ROM is not different between baseball players with a UCL tear compared to a matched healthy cohort.

LEVEL OF EVIDENCE

Level 3.

Shoulder Pain and Rotational Range of Motion of the Trunk, Shoulder, and Hip in Baseball Players

CONTEXT

Deficient glenohumeral rotational range of motion (ROM) is a risk factor for shoulder pain. Adapted ROM of the trunk and hip in response to loss of glenohumeral ROM has been suggested, as the nature of baseball leads to ROM adaptations.

OBJECTIVE

To compare the bilateral rotational ROM values of the trunk and glenohumeral and hip joints in adolescent baseball players with or without shoulder pain and to measure the correlation between shoulder-pain intensity and bilateral rotational ROM values for each body area.

DESIGN

Cross-sectional study.

SETTING

Research laboratory.

PATIENTS OR OTHER PARTICIPANTS

Ninety-five adolescent baseball players (60 with shoulder pain, 35 without shoulder pain).

MAIN OUTCOME MEASURE(S)

Bilateral trunk rotation and internal rotation, external rotation, and total rotation of the dominant and nondominant glenohumeral and hip joints.

RESULTS

Glenohumeral and hip ROM did not differ between groups, and pain intensity and rotational ROM were not related in either joint. Trunk rotational ROM was greater in the pain group than in the control group (dominant side = 48.8° ± 14.2° versus 41.8° ± 11.9°, respectively; nondominant side = 45.1° ± 14.2° versus 38.9° ± 7.7°, respectively; P values < .05), although the difference was clinically small (mean differences = 7.0° ± 2.7° [95% confidence interval = 1.7, 12.4] on the dominant side, P = .01, and 6.1° ± 2.7° [95% confidence interval = 0.8, 11.5] on the nondominant side, P = .03). Positive but low correlations in all players (ρ = 0.27, P = .01) and in those with shoulder pain (ρ = 0.36, P = .001) were present between shoulder-pain intensity and trunk rotational ROM toward the dominant side.

CONCLUSIONS

We found no clinical relationship between shoulder pain and rotational ROM and no clinical differences in rotational ROM values between players with and those without shoulder pain.

SHOULDER RANGE OF MOTION CHARACTERISTICS IN DIVISION III COLLEGIATE SOFTBALL AND BASEBALL PLAYERS

BACKGROUND

Adaptive changes may occur to the throwing shoulder of overhead athletes that can influence range-of-motion (ROM). Shoulder ROM characteristics of Division III softball (SB) and baseball (BB) players are unique.

HYPOTHESIS/PURPOSE

To report the passive ROM characteristics of Division III SB and BB players and identify similarities and differences between these two populations.

STUDY DESIGN

Descriptive, observational research on measurement.

METHODS

Participants included healthy Division III BB (n = 50) and SB (n = 24) players. Passive shoulder internal rotation (IR) and external rotation (ER) ROM were measured in the supine position with the arm in 90 ° of abduction and the scapula stabilized. Descriptive statistics and frequency distributions were used to describe ROM. Paired and independent t-tests were also used to compare throwing and non-throwing shoulder ROM for athletes of each sport and to compare the shoulder ROM of SB and BB players, respectively.

RESULTS

The IR and ER ROM for BB players throwing shoulders (IR 54.1 ± 10.9 °; ER 94.1 ± 9.1 °) were significantly different (p < 0.001) from their non-throwing shoulders (IR 63.3 ± 11.1 °; ER 87.6 ± 9.2 °) while SB players were not (p = .06 & .08, respectively). Compared to the BB players, the throwing shoulder of SB players demonstrated statistically significantly higher IR ROM (p < .001, mean difference = 11.8 °, 95% CI: 6.4-17.2 °) as well as higher total range of motion (TRM) (p < .001, mean difference = 14.4 °, 95% CI: 8.6-20.2 °) when compared to BB players. Glenohumeral internal rotation deficit (GIRD) was significantly higher in BB players when compared to SB players (p = .042, 95% CI: .2-10.8 °). There were no significant differences in IR, ER, TRM, GIRD and ER gain between SB or BB pitchers and all other field positions (p > .05).

CONCLUSIONS

SB players have more ROM and bilateral symmetry when compared to BB players. TRMD occurred more often than GIRD in BB players, indicating that they did not adaptively gain the same amount of ER while losing IR. The throwing shoulder ROM characteristics of both SB and BB players in this study were not influenced by the player's position (pitcher vs. field player).

LEVEL OF EVIDENCE

Level III.

Passive range of motion of the hips and shoulders and their relationship with ball spin rate in elite finger spin bowlers

OBJECTIVES

Investigate rotational passive range of motion of the hips and shoulders for elite finger spin bowlers and their relationship with spin rate.

DESIGN

Correlational.

METHODS

Spin rates and twelve rotational range of motion measurements for the hips and shoulders were collected for sixteen elite male finger spin bowlers. Side to side differences in the rotational range of motion measurements were assessed using paired t-tests. Stepwise linear regression and Pearson product moment correlations were used to identify which range of motion measurements were linked to spin rate.

RESULTS

Side to side differences were found with more external rotation (p = 0.039) and less internal rotation (p = 0.089) in the bowling shoulder, and more internal rotation in the front hip (p = 0.041). Total arc of rotation of the front hip was found to be the best predictor of spin rate (r = 0.552, p =  0.027), explaining 26% of the observed variance. Internal rotation of the rear hip (r = 0.466, p =  0.059) and the bowling shoulder (r = 0.476, p =  0.063) were also associated with spin rate.

CONCLUSIONS

The technique and performance of elite finger spin bowlers may be limited by the passive range of motion of their hips and shoulders. The observed side to side differences may indicate that due to the repetitive nature of finger spin bowling adaptive changes in the rotational range of motion of the hip and shoulder occur.

Editorial Commentary: I Have a Hip Labral Tear? Well, That Makes Sense Because I Had a Labral Tear in My Shoulder Too

Most acetabular labral tears are caused by abnormal osseous morphology, such as cam and/or pincer morphology and dysplasia. There is a high prevalence of asymptomatic cam morphology, pincer morphology, dysplasia, and acetabular labral tears in the general population. The addition of subjective patient symptoms and objective physical examination findings to imaging (plain radiographs, magnetic resonance imaging, and computed tomography) may yield the diagnosis of femoroacetabular impingement syndrome. Most glenoid labral tears (e.g., Bankart lesion, posterior labral tear, or SLAP tear) are caused by either glenohumeral instability or a degenerative process. Similarly to the acetabular labrum, there is a high prevalence of asymptomatic glenoid labral tears in an asymptomatic population. Hip pathomorphology (e.g., cam impingement) can have a significant biomechanical impact both upstream and downstream on the kinetic chain (lumbosacral spine, periarticular hip musculature [athletic pubalgia, core muscle injury, sports hernia], knee [anterior cruciate ligament], and shoulder and elbow). Thus, it is tempting to believe that the hip issue may cause the shoulder issue or that an innate genetic (or acquired) abnormality may predispose both joints to labral injury. However, the wise clinician will not be lured into this trap-correlation does not equal causation. Biomechanical studies that evaluate stress transfer from the hip to the shoulder, in addition to clinical studies that prospectively follow these groups, will help to answer this highly relevant question.

Sacroiliac Stretching Improves Glenohumeral Internal Rotation Deficit of the Opposite Shoulder in Baseball Players in a Randomized Control Trial

Introduction:

Glenohumeral internal rotation deficit (GIRD) is a well-documented finding in throwing athletes.

Purpose:

To investigate whether stretching the contralateral sacroiliac (SI) joint can improve GIRD in baseball players.

Method:

After internal shoulder rotation was measured in 23 minor league baseball players, the players randomly were assigned to either a control (ie, sleeper stretch of the dominant shoulder) or experimental (ie, SI joint stretch contralateral to the dominant shoulder) group. Afterward, internal rotation (IR) of their dominant shoulders was remeasured.

Results:

The mean initial end-range IR was 68.6° (SD = 7.9°) in the sleeper stretch group (n = 8) and 64.5° (SD = 5.1°) in the SI joint stretch group (n = 15). After stretching, the sleeper stretch group's mean end-range IR was 72.1° (SD = 7.2°), a 3.5° improvement (P = 0.1058), whereas the contralateral SI joint stretch group's mean end-range IR was 71.9° (SD = 6.6°), a 7.4° improvement (P = 0.0041).

Conclusions:

Stretching the contralateral SI joint improved GIRD more than the sleeper's stretch.

NONOPERATIVE TREATMENT FOR INJURIES TO THE IN-SEASON THROWING SHOULDER: A CURRENT CONCEPTS REVIEW WITH CLINICAL COMMENTARY

Repetitive overhead throwing generates tremendous demands on the shoulder joint of the overhead athlete. Clinicians, therapists, and medical staff are charged with optimizing a throwing athlete's shoulder mobility and stability to maximize performance and prevent injury. Modifiable risk factors such as strength asymmetry, glenohumeral range of motion deficits, and scapulothoracic joint abnormalities contribute to the overhead athlete's predisposition to shoulder injury. Most shoulder injuries in the overhead thrower can be successfully treated nonoperatively to allow in-season return to sport. The optimal rehabilitation program must be based on an accurate evaluation of historical and physical information as well as diagnostic imaging. Return to play decisions should be individualized and should weigh subjective assessments along with objective measurements of range of motion, strength, and function. The purpose of this clinical commentary is to summarize the current literature regarding the nonoperative treatment options for these common injuries, and to present a treatment plan to safely return these athletes to the field of play.

Level of evidence

5.

The Impact of Workload on the Evolution of Hip Internal and External Rotation in Professional Baseball Players Over the Course of the Season

Background

Although restricted hip range of motion (ROM) is associated with an increased risk for injuries in baseball players, the evolution of hip ROM over the season remains undefined.

Hypothesis

Hip ROM profiles would be symmetric between hips and positions (pitchers vs position players) but would decrease from preseason to postseason. Additionally, it was hypothesized that this decrease in motion would correlate with workload.

Study Design

Cohort study; Level of evidence, 2.

Methods

Bilateral hip ROM was assessed in 96 professional baseball players (54 pitchers, 42 position players) preseason and postseason. ROM comparisons were made between lead and trailing hips, pitchers and position players, and preseason and postseason measures. The change from preseason to postseason was correlated with player demographics and measures of workload for pitchers and position players.

Results

Preseason hip ROM was symmetric between hips; however, pitchers demonstrated increased preseason lead hip internal rotation (IR) (P = .018) and bilateral hip total ROM (TROM) (P < .020) compared with position players. From preseason to postseason, position players lost 7° of external rotation (ER) (P ≤ .005 ). In pitchers, the loss of IR correlated with increased pitches (P = .016) and innings (P = .037), while the loss of ER (P = .005 ) and TROM (P = .014) correlated with increasing mean fastball velocity. Workload for position players did not correlate with motion loss.

Conclusion

Symmetric hip ROM profiles should be anticipated in baseball players; however, pitchers may have increased preseason IR and TROM and postseason ER and TROM relative to position players. Although loss of motion correlated with workload in pitchers, this was not the case for position players. Hip motion should be monitored over the course of the season. This is particularly true for pitchers who lose IR as workload increases, which may place them at a greater risk for injuries.

Lower Extremity Strength and Recovery Time in Youth Baseball Pitchers: A Pilot Study

Livingston, JL and Tavoukjian, NM. Lower extremity strength and recovery time in youth baseball pitchers: a pilot study. J Strength Cond Res 34(7): 1990-1998, 2020-The purpose of this study was to investigate the Little League pitching regulations by measuring the change in lower extremity force production after a pitching performance and the subsequent days of rest required for youth baseball pitchers to recover. Bilateral manual muscle testing of the gluteus maximus, hamstrings, gluteus medius, triceps surae, and quadriceps was conducted using a handheld dynamometer. Fifteen healthy, youth baseball pitchers (9.80 ± 1.08 years) threw a submaximal number of pitches and were tested before, immediately after, and for the next 4 consecutive days. Time in days required per muscle group to return to baseline force production levels were compared with Little League rest guidelines for pitchers. Results indicated that Little League rest requirements did not allow for sufficient recovery of lower extremity strength (p = 0.017). Results suggest that current Little League pitching guidelines provide an inadequate recovery period for youth pitchers, even when pitching a submaximal volume. Little League pitch count regulations and associated rest days may require revisions to avoid having youth athletes pitch while fatigued.

Pitch Volume and Glenohumeral and Hip Motion and Strength in Youth Baseball Pitchers

CONTEXT

  Increased pitch volume and altered glenohumeral (GH) and hip range of motion (ROM) and strength contribute to injury risk in baseball pitchers. Although these factors affect one another, whether they are related is unknown.

OBJECTIVE

  To examine relationships among cumulative and seasonal pitch volume, ROM, and strength of the GH and hip joints in youth baseball pitchers.

DESIGN

  Cross-sectional study.

SETTING

  Baseball practice facilities.

PATIENTS OR OTHER PARTICIPANTS

  A total of 28 healthy baseball pitchers (age = 13.9 ± 2.9 years).

MAIN OUTCOME MEASURE(S)

  A demographic and pitching questionnaire was used to quantify pitch volume. Glenohumeral internal-rotation (IR) and external-rotation (ER) ROM and strength of the throwing arm; total arc of motion (IR + ER ROM); and bilateral hip IR, ER, and total arc of motion ROM and strength in IR, ER, and abduction were measured. A goniometer was used to assess ROM; a handheld dynamometer, to assess strength. Frequency analyses and bivariate correlations (age covariate) described data and identified relationships.

RESULTS

  Correlations between years of competitive play and increased strength in lead-leg hip IR ( r = 0.52, P = .02) and abduction ( r = 0.48, P = .04) and stance-leg hip IR ( r = 0.45, P = .05) were fair to good. The number of months played in the last year had a fair correlation with decreased GH IR strength ( r = -0.39, P = .04) and increased stance-leg hip IR strength ( r = 0.44, P = .05). Limited pitch time had a fair correlation with increased GH ER ROM ( r = 0.40, P = .04) and an excellent correlation with increased lead-leg hip IR ROM ( r = 0.79, P < .001). Increased innings pitched per game had a fair to good correlation with decreased GH IR strength ( r = -0.41, P = .04) and stance-leg hip ER ROM ( r = -0.53, P = .03). More pitches per game had a fair to good correlation with increased GH ER ROM ( r = 0.44, P = .05) and decreased stance-leg hip ER ROM ( r = -0.62, P = .008).

CONCLUSIONS

  The significant relationships identified in this study suggest the need to further examine youth and adolescent cumulative and seasonal pitch guidelines.

HIP RANGE OF MOTION IN RECREATIONAL WEIGHT TRAINING PARTICIPANTS: A DESCRIPTIVE REPORT

BACKGROUND

The surveillance of hip injuries and risk factors have become an emerging focus in sports medicine due to the increased recognition of hip pathologies. Researchers suggest that decreased hip range of motion (ROM) is a risk factor for injury in various athletic activities. One under reported population that has potential for hip injuries is recreational weight training (WT) participants. Currently, no studies have reported hip ROM values in WT participants which creates a knowledge gap in this population.

PURPOSE

The purpose of this study was to report hip passive ROM values of WT participants to develop reference data for future research on injury patterns and prevention strategies for this population.

STUDY DESIGN

Descriptive cross sectional study.

METHODS

Two-hundred healthy recreational adult WT participants (age = 27.18 ± 9.3 years, height = 174.84 ± 9.8 cm, mass = 91.0 ± 17.9 kg, body mass index = 29.6 ± 4.5 kg/m2) were recruited. Bilateral hip passive ROM was assessed for flexion, extension, internal rotation, external rotation, and abduction. Statistical analysis included subject demographics (means and SD) and a two-tailed independent t-test to compare mean passive hip ROM values between sexes and hips. Statistical significance was considered p < .05.

RESULTS

A total of 400 hundred hips (right + left) were measured for this analysis. When comparing hip ROM values within sexes, men had no significant difference (p≥.28) between the right and left hip for all motions. Women did have a significant difference (p≤.05) between the right and left hip for all motions. The right hip had lower values for all motions than the left hip suggesting a more global decrease in right hip ROM. When comparing hip ROM values between men and women, there was a significant difference (p≤.05) between men and women for all motions. Men had lower ROM values for all hip motions when compared to women.

CONCLUSION

This is the first investigation to provide a descriptive analysis of hip ROM in healthy recreational WT participants. These data provide a starting point for clinicians and researchers to further study this population for injury prevention.

EVIDENCE LEVEL

2.