BASEBALL PLAYERS WITH ULNAR COLLATERAL LIGAMENT TEARS DEMONSTRATE DECREASED ROTATOR CUFF STRENGTH COMPARED TO HEALTHY CONTROLS

Background

Ulnar Collateral Ligament (UCL) tears are common in baseball players. Alterations in rotator cuff strength are believed to be associated with injury to the shoulder and/or elbow in baseball players.

Hypothesis/Purpose

Baseball players diagnosed with a UCL tear will demonstrate decreased internal (IR) and external rotation (ER) force as an indication of isometric muscular strength in the throwing arm compared to IR and ER force of the throwing arm in healthy baseball players. The purpose of this study was to examine isometric IR and ER strength of the shoulder in baseball players with UCL tears at the time of injury compared to healthy baseball players.

Study Design

Case‐control study design

Methods

Thirty‐three of the participants were diagnosed with a UCL tear and thirty‐three were healthy, age‐ and positioned‐matched controls. All of the participants played baseball at either the high school or collegiate level and volunteered for the study. Isometric rotator cuff strength measurements for internal (IR) and external rotation (ER) were performed with the arm held to the side at 0 ° of shoulder abduction. All measurements were taken bilaterally and the means of the throwing and non‐throwing arms for IR and ER in the UCL group were compared to the means of the throwing and non‐throwing arms in the healthy group. One‐way ANOVAs were used to calculate differences between groups (p < 0.05).

Results

Baseball players with UCL tears demonstrated significant rotator cuff strength deficits on their throwing arm IR (p < .001) and ER (p < .001) compared to throwing arm IR and ER in the Healthy (UCL IR = 131.3 ± 31.6 N; Healthy IR = 174.9 ± 20.7 N) (UCL ER = 86.4 ± 18.3 N; Healthy ER = 122.3 ± 18.3 N). On the non‐throwing arm, the UCL group was weaker in both IR (135.0 ± 31.1 N; p < .001) and ER (93.4 ± 22.8 N; p < .001) than IR (172.1 ± 24.1 N) and ER (122.3 ± 19.1 N) in the Healthy group.

Conclusion

Participants with a UCL tear exhibit lower force values as an indication of isometric rotator cuff strength in both the throwing and non‐throwing arms than a healthy cohort.

Level of Evidence

Level 4     

BILATERAL DIFFERENCES IN THE UPPER QUARTER FUNCTION OF HIGH SCHOOL AGED BASEBALL AND SOFTBALL PLAYERS

Purpose/Background:

The Upper Quarter Y Balance Test (YBT‐UQ) was developed as a way to identify upper extremity and trunk mobility in the open kinetic chain in the reaching limb as well as midrange limitations and asymmetries of upper extremity and core stability in the closed kinetic chain on the stabilizing limb. Performance on the YBT‐UQ is similar between genders and between limbs; however, this has not been examined in athletes who participate in sports that result in upper extremity asymmetries. The primary purpose of this study is to determine if differences exist between the throwing vs. non‐throwing sides in high‐school baseball and softball athletes on the YBT‐UQ.

Methods:

In order to complete this forty‐eight male high school baseball players and seventeen female high school softball players were tested on the YBT‐UQ. Reach distances were normalized to arm length (% AL). Comparisons were made between the throwing (T) and non‐throwing (NT) arm for each direction as well as the composite score.

Results:

No significant differences were observed between the T and NT arm for the medial (NT: 98.4 ± 8.6 %AL, T: 99.1 ± 8.6 %AL, p=0.42), inferolateral (NT: 90.8 ± 11.8 %AL, T: 90.3 ± 11.5 %AL, p =0.61), superolateral (NT: 70.6 ± 10.9 %AL, T: 70.4 ± 11.1 % AL, p=0.91) reaches, or the composite score (NT: 87.2 ± 8.9 % AL, T: 86.6 ± 8.1 %AL, p=0.72). Similarly, no differences were observed between the male baseball and female softball players (p=0.30‐0.90).

Conclusions:

Based on these findings, it was concluded that there was no difference in performance on the YBT‐UQ between throwing and non‐throwing limbs in high school baseball and softball players.

Level of Evidence:

3     

ACUTE EFFECTS OF INSTRUMENT ASSISTED SOFT TISSUE MOBILIZATION FOR IMPROVING POSTERIOR SHOULDER RANGE OF MOTION IN COLLEGIATE BASEBALL PLAYERS

Background:

Due to the repetitive rotational and distractive forces exerted onto the posterior shoulder during the deceleration phase of the overhead throwing motion, limited glenohumeral (GH) range of motion (ROM) is a common trait found among baseball players, making them prone to a wide variety of shoulder injuries. Although utilization of instrument‐assisted soft tissue mobilization (IASTM), such as the Graston® Technique, has proven effective for various injuries and disorders, there is currently no empirical data regarding the effectiveness of this treatment on posterior shoulder tightness.

Purpose:

To determine the effectiveness of IASTM in improving acute passive GH horizontal adduction and internal rotation ROM in collegiate baseball players.

Methods:

Thirty‐five asymptomatic collegiate baseball players were randomly assigned to one of two groups. Seventeen participants received one application of IASTM to the posterior shoulder in between pretest and posttest measurements of passive GH horizontal adduction and internal rotation ROM. The remaining 18 participants did not receive a treatment intervention between tests, serving as the controls. Data were analyzed using separate 2× 2 mixed‐model analysis of variance, with treatment group as the between‐subjects variable and time as the within‐subjects variable.

Results:

A significant group‐by‐time interaction was present for GH horizontal adduction ROM with the IASTM group showing greater improvements in ROM (11.1°) compared to the control group (‐0.12°) (p <0.001). A significant group‐by‐time interaction was also present for GH internal rotation ROM with the IASTM group having greater improvements (4.8°) compared to the control group (‐0.14°) (p < 0.001).

Conclusions:

The results of this study indicate that an application of IASTM to the posterior shoulder provides acute improvements in both GH horizontal adduction ROM and internal rotation ROM among baseball players.

Level of Evidence:

2b     

REGIONAL INTERDEPENDENCE OF THE HIP AND LUMBO‐PELVIC REGION IN DIVISON II COLLEGIATE LEVEL BASEBALL PITCHERS: A PRELIMINARY STUDY

Background

Pitchers may be at greater risk of injury in comparison to other overhead throwing athletes due to the repetition of the pitching motion. It has been reported that approximately 30% of all baseball injuries occur in the lower body. This may be related to limited hip mobility, which can compromise pitching biomechanics while placing excessive stress on the trunk and upper quarter. Hip motion and strength measurements have been reported in professional baseball pitchers but have not been reported in collegiate pitchers.

Purpose

The purpose of this study was to report preliminary findings for passive hip motion and isometric hip muscle strength in collegiate pitchers and compare them to previously published values for professional level pitchers.

Study Design

Cross sectional study

Methods

Twenty‐nine collegiate baseball pitchers (age = 20.0 + 1.4 years, height = 1.88 + 0.06 m; weight = 89.3 + 10.7 kg; body mass index = 25.3 + 2.5 kg/m2) were recruited. Subjects were assessed for hip internal rotation (IR) and external rotation (ER) passive motion, hip anteversion or retroversion, gluteus maximus, gluteus medius, hip internal rotator, hip external rotator strength, and lumbo‐pelvic control with the prone active hip rotation test as described by Sahrmann. Statistical analysis included calculation of subject demographics (means and SD) and use of a two‐tailed t‐test (p >0.05).

Results

Fifty‐two percent of the right‐handed and 50% of the left‐handed pitchers demonstrated poor lumbo‐pelvic motor control with an inability to stabilize during active hip IR and ER even though isolated strength deficits were not detected at a significant level. There were no significant differences in hip passive motion or gluteus medius strength between right and left‐handed pitchers. Differences did exist between collegiate data and previously published values for professional pitchers for IR motion measured in prone and gluteus maximus strength. Hip retroversion was present in 55% of the pitchers primarily in both limbs with four of the pitchers presenting with retroversion singularly in either the stride or trail limb where the ER rotation motion was greater than the IR.

Conclusion

Assessing mobility and muscle strength of the lower quarter in isolation can be misleading and may not be adequate to ensure the potential for optimal pitching performance. These findings suggest that lumbo‐pelvic control in relation to the lower extremities should be assessed as one functional unit. This is the first study to explore hip motion, strength, and lumbo‐pelvic control during active hip rotation in collegiate baseball pitchers.

Evidence Level

2     

A TOTAL MOTION RELEASE WARM‐UP IMPROVES DOMINANT ARM SHOULDER INTERNAL AND EXTERNAL ROTATION IN BASEBALL PLAYERS

Context:

Current literature indicates a correlation between decreased total shoulder range of motion (ROM) and internal rotation (IR) of the dominant arm and increased injury risk in throwers. The optimal method for increasing shoulder ROM, improving performance, and preventing injury is unknown. It is also unknown if treating the non‐dominant arm may affect ROM on the dominant side.

Purpose:

To explore the effect of the Total Motion Release (TMR®) Trunk Twist (TT) and Arm Raise (AR) on IR and external rotation (ER) of the dominant shoulder in baseball players compared to a traditional dynamic warm‐up.

Design:

Cohort study.

Setting:

University athletic training clinic and baseball field.

Participants:

Pitchers (males, n = 10; age, 18.6 ± 1.3) recruited from local baseball teams were randomly assigned two one of two groups: TMR® treatment group (TMRG; n = 5) or traditional warm‐up group (TWG; n = 5).

Interventions:

Baseline IR and ER goniometry range of motion (ROM) measurements were recorded. The TMRG then completed the TMR® exercises and post‐intervention measurements. The TWG completed a traditional static and dynamic warm‐up (e.g., lunges, power skips, sprints, sleeper stretch) and then completed post‐intervention measurements. Following the completion of those measurements, the TWG completed the TMR® Trunk Twist and Arm Raise protocol and had post‐intervention measurements recorded once more.

Main Outcome Measures:

ROM measures for IR and ER of the dominant shoulder. Alpha level was set at p ≤ 0.05.

Results

Significant differences were present for IR (p = 0.025) and ER (p = 0.014) between the TMRG and the TWG after initial intervention. Significant differences for IR were present in the TWG between baseline and TMR® intervention and traditional warm‐up and TMR® intervention. For the TWG, changes in ER were not statistically significant at baseline, post‐warm‐up, or post‐ TMR® intervention. Significant differences were not present for IR (p = 0.44) or ER (p = 0.23) between groups once TMR® had been completed by both groups.

Conclusions:

TMR® produced larger increases in IR and ER of the throwing shoulder when compared to the TWG. Generalizability is limited, however, by the low number of participants in each group and a potential ceiling effect of attainable ROM gains. Future studies should examine if using a full TMR® treatment process is more beneficial. Additionally, future research should compare TMR® intervention to other warm‐up activities or stretching protocols (e.g. resistance tubing, weighted balls) and examine its effect across other variables (e.g., injury rates, throwing velocity).

Level of Evidence:

Clinical Evidence Based Level 2b     

KNOWLEDGE OF INJURY PREVENTION AND PREVALENCE OF RISK FACTORS FOR THROWING INJURIES IN A SAMPLE OF YOUTH BASEBALL PLAYERS

Background

Information on baseball injury prevention and pitch count recommendations is growing, however, the incidence of throwing injuries continues to rise. This study is the first to assess knowledge of safe throwing guidelines and risk factors from the perspective of youth athletes.

Purpose

The purpose of this study is two‐fold: (1) to evaluate knowledge of safe throwing guidelines and (2) to assess the reporting of risk factors for throwing injuries in a sample of youth baseball players.

Study Design

Survey study of 98 overhead athletes between the ages of 4 and 18.

Methods

A 35‐question survey was developed with questions related to knowledge of injury prevention, presence of risk factors associated with throwing injuries, and understanding and compliance with USA Baseball Medical & Safety Advisory Committee (USA BMSAC) overhead throwing guidelines.

Results

Respondents demonstrated variability in their knowledge of the USA BMSAC guidelines related to throwing frequencies. The 13‐16 year old age group displayed the least knowledge of USA BMSAC guidelines. The 9‐10 and 11‐12 year old age groups demonstrated the greatest knowledge of recommended BMSAC guidelines. Eighty‐five (82/98) percent of the respondents reported that they had never heard of the USA BMSAC guidelines. Sixty‐two percent (59/98) disagreed with the statement, “The more you throw, the more likely you are to get an injury”. Fifty‐seven percent of respondents (39/98) indicated that they would not seek medical help if they experienced a tired or sore arm during a game.

Conclusion

The results of this study suggest that young baseball players demonstrate the need for education on the following topics: the USA Baseball Medical and Safety Advisory Committee throwing guidelines, risk factors for developing throwing‐related injuries, the long‐term implications of playing with an injured or fatigued arm, and the benefit of seeking medical help when fatigue or soreness is experienced in the throwing arm.

Level of Evidence

Level 3     

CHANGES IN HIP RANGE OF MOTION AND STRENGTH IN COLLEGIATE BASEBALL PITCHERS OVER THE COURSE OF A COMPETITIVE SEASON: A PILOT STUDY

Background

Adaptations in hip range of motion (ROM) and strength have been shown to influence performance and injury risk in overhead athletes. These adaptations in hip ROM and strength have not been examined longitudinally, and little is known regarding whether these changes are a result of pitching workload.

Hypothesis/Purpose

The authors hypothesized that hip rotation ROM and strength would change over the course of a season, and would be associated with pitching workload (number of pitches over the course of a season). The purpose of this exploratory, pilot study was twofold: 1) to examine changes in hip external rotation (ER) ROM, internal rotation (IR) ROM, isometric hip abduction and hip extension strength in pitchers occurring over the course of a competitive season, and 2) to determine the association between changes in hip ROM, strength, and pitching volume.

Study Design

Cohort (longitudinal) study

Methods

Bilateral hip rotation ROM and hip isometric strength was tested pre‐ and post‐season in fourteen collegiate baseball pitchers. Pearson correlations were calculated to determine the association between changes in hip ROM, strength, and pitching workload.

Results

Trail and lead hip ER, trail and lead hip total rotational ROM, and trail and lead hip abduction strength in all pitchers decreased from preseason to postseason (p < 0.01). However, these changes were not significantly associated with pitching workload (p > 0.05).

Conclusion

This study demonstrates that changes occur in hip ROM and strength in collegiate pitchers over the course of a season. These changes were not associated with pitching workload

Level of Evidence

3     

THE EFFECTS OF A DAILY STRETCHING PROTOCOL ON PASSIVE GLENOHUMERAL INTERNAL ROTATION IN OVERHEAD THROWING COLLEGIATE ATHLETES

Introduction/Purpose:

Shoulder dysfunction and injury are common in throwing athletes. Loss of internal rotation has been correlated to shoulder pathologies. The purpose of this study was to assess the effects of a stretching protocol on passive internal rotation. The purpose of this study was assess the effects of a stretching protocol on passive internal rotation motion in the throwing shoulders of collegiate baseball players.

Study Design:

Pre-Post, intervention, using a within subjects comparison of a convenience sample.

Methods:

Glenohumeral internal rotation and external rotation of the throwing and non-throwing shoulders of NCAA Division I baseball players were measured using a universal goniometer. Determinations were made as to the degree of Glenohumeral Internal Rotation Deficit (GIRD) in the throwing shoulder. A daily (5 days per week), 12-week posterior capsule stretching program was administered. Post-stretching internal rotation and external rotation measures were again obtained. The coaches and athletic trainers of the included team monitored the players for shoulder injuries and innings of training/competition lost due to shoulder injuries during the 12 week intervention.

Results:

A significant increase in range of motion was found for dominant arm internal rotation (IR) and total range of motion (TOT) following the stretching program. No statistically significant improvement in range of motion was found for external rotation (ER), non-throwing arm internal rotation (NDIR), non-throwing arm external rotation (NDER), and non-throwing arm total motion (NDTOT).

Conclusions:

Implementation of a posterior capsule stretching program may be helpful to facilitate increased passive internal rotation range of motion at the glenohumeral joint. Further research should be performed using a control group not receiving the stretching program in order to more completely establish the impact of stretching on measures of passive glenohumeral range of motion.

Level of Evidence:

1b     

GLENOHUMERAL ROTATIONAL RANGE OF MOTION DIFFERENCES BETWEEN FAST BOWLERS AND SPIN BOWLERS IN ELITE CRICKETERS

Background:

The shoulder, particularly the glenohumeral joint with its predominant reliance upon soft tissues for stability is prone to injury among the cricketers who bowl regularly. These shoulder injuries are more common in spin bowlers than fast bowlers. A decreased internal rotational difference and increased external rotational difference exist when comparing the dominant shoulder with non‐dominant shoulder between overarm cricketers and non‐throwing wicket keepers.

Purpose:

To compare the glenohumeral internal and external rotation range of motion differences between fast bowlers and spin bowlers.

Methods:

A cross‐sectional design was utilized for this study. Thirty‐five fast bowlers and 31 spin bowlers from an elite group were recruited based on the selection criteria. Glenohumeral passive internal and external rotational differences between dominant and non‐dominant shoulders were measured using a standardized mechanical inclinometer.

Results:

Independent t‐tests revealed a statistically significant difference for external rotational difference (p=0.005) between fast and spin bowlers and no such difference for internal rotational difference (p=0.549) between them at 0.05 level.

Conclusion:

External rotational difference is significantly different between fast bowlers and spin bowlers but not internal rotational difference.

Level of Evidence:

Level 4     

TOTAL ARC OF MOTION IN THE SIDELYING POSITION: EVIDENCE FOR A NEW METHOD TO ASSESS GLENOHUMERAL INTERNAL ROTATION DEFICIT IN OVERHEAD ATHLETES

Background

Total arc of motion (TA) measured in a supine position has been utilized as a method to detect the presence of glenohumeral internal rotation deficit (GIRD) in overhead athletes. A component of supine TA is supine internal rotation (IR) range of motion (ROM), which has many variables including the amount and location of manual stabilization. A sidelying position for gathering IR ROM has recently been proposed and, when combined with supine external rotation (ER) ROM, constitutes a new method of quantifying TA. This new sidelying TA method, however, has no normative values for overhead athletes.

Purpose

The purposes of this study were to develop normative values for sidelying TA in overhead athletes, determine any ROM difference between supine and sidelying TA, and examine side‐to‐side differences within the two TA methods. A secondary purpose of the study was to examine for any effect of gender or level of competition on the two TA methods.

Study Design

Cross‐sectional study.

Methods

Passive supine IR ROM, supine ER ROM, and sidelying IR ROM were gathered on bilateral shoulders of 176 collegiate and recreational overhead athletes (122 male [21.4 ± 4.7 years, 71.7 ± 2.7 inches, 25.3 ± 2.7 BMI] and 54 female [21.4 ± 5.4 years, 67.6 ± 3.0 inches, 22.5 ± 2.37 BMI]).

Results

Sidelying TA mean for the dominant shoulder was 159.6 °±15.0 °; the non‐dominant shoulder was 163.3 °±15.3 °. Sidelying TA for both shoulders (p < 0.0001) was 14 ° less than supine TA. Both TA methods exhibited a 4 ° dominant‐shoulder deficit (p < 0.0001). For the dominant and non‐dominant shoulder, respectively, there was no gender (p = 0.38, 0.54) or level of competition (p = 0.23, 0.39) effect on sidelying TA.

Conclusion

In overhead athletes, sidelying TA is a viable alternative to supine TA when examining for the presence of GIRD. Gender and level of competition does not significantly affect sidelying TA, so the mean of 160 ° on the dominant shoulder and 163 ° on the non‐dominant shoulder can be used by clinicians.

Level of Evidence

Level 3     

THROWING INJURIES IN THE ADOLESCENT ATHLETE

Introduction:

Adolescents ranging in age from 11–15 (early‐mid adolescence) comprise the largest percentage of baseball and softball athletes in the United States. Shoulder and elbow injuries are commonly experienced by these athletes with baseball pitchers and softball position players most likely to be injured.

Common Injuries:

Physeal injury often termed “Little League” shoulder or elbow is common and should be differentiated from soft tissue injuries such as biceps, rotator cuff, or UCL injuries. Regardless of diagnosis, rehabilitation of these athletes’ shoulder and elbow injuries provide a unique challenge given their rapidly changing physical status.

Treatment:

Common impairments include alterations in shoulder range of motion, decreased muscle performance, and poor neuromuscular control of the scapula, core, and lower extremity. A criterion based, progressive rehabilitation program is presented. Discharge from formal rehabilitation should occur only when the athlete has demonstrated a resolution of symptoms, acceptable ROM, muscle performance, and neuromuscular control while progressing through a symptom free return to sport.

Prevention of Reinjury:

Reintegration into the desired level of sport participation should be guided by the sports medicine professional with a focus on long‐term durability in sport performance as well as injury prevention. A prevention program which includes parent, coach, and athlete education, regular screening to identify those athletes at the highest risk, and monitoring athletes for the development of risk factors or warning signs of injury over the course of participation is indicated.

Level of Evidence:

5     

PASSIVE HIP RANGE OF MOTION IS REDUCED IN ACTIVE SUBJECTS WITH CHRONIC LOW BACK PAIN COMPARED TO CONTROLS

Background

Non‐specific low back pain is a common condition often without a clear mechanism for its presentation. Recently more attention has been placed on the hip and its potential contributions to non‐specific chronic low back pain (NSCLBP). Emphasis in research has mainly been placed on motor control, strength and endurance factors in relation to NSCLBP. Limited focus has been placed on hip mobility and its potential contribution in subjects with NSCLBP.

Purpose/Aim

The aim of this study was to compare passive ROM in hip extension, hip internal rotation, hip external rotation and total hip rotation in active subjects with NSCLBP to healthy control subjects. The hypothesis was that active subjects with NSCLBP would present with decreased total hip ROM and greater asymmetry when compared to controls.

Design

Two group case controlled

Setting

Clinical research laboratory

Participants

30 healthy subjects without NSCLBP and 30 active subjects with NSCLBP. Subjects categorized as NSCLBP were experiencing pain in the low back area with or without radicular symptoms of greater than three months duration.

Main Outcome Measure

Passive hip extension (EXT), hip internal rotation (IR), hip external rotation (ER) and total hip rotation ROM. A digital inclinometer was used for measurements.

Results

There was a statistically significant difference (p<0.001) in hip passive extension ROM between the control group and the NSCLBP group bilaterally. Mean hip extension for the control group was 6.88 bilaterally. For the NSCLBP group, the mean hip extension was ‐4.28 bilaterally. This corresponds to a difference of means between groups of 10.88. There was no statistically significant differences (p>0.05) in hip IR, ER, or total rotation ROM between groups.

Conclusions

The results of this study indicate that a significant difference in hip extension exists in active subjects with NSCLBP compared to controls. It may be important to consider hip mobility restrictions and their potential impact on assessment of strength in NSLBP subjects. Future studies may be needed to investigate the relationship between measurements and intervention strategies.

Level of Evidence

2b     

Professional Baseball Player Type and Geographic Region of Origin Impacts Shoulder External and Internal Rotation Strength

BackgroundShoulder strength deficits are implicated in arm injuries and performance deficits in baseball players.PurposeTo characterize shoulder external (ER) and internal (IR) rotation strength in professional baseball players, and compare strength across player type (pitchers, position players) and geographic origin (North America, Latin America).Study DesignCross-sectional.MethodsMinor league professional baseball players from North America and Latin America (n=242; age=22.4±2.3 years; n=135 pitchers and n=107 position players; n=162 North American and n=80 Latin American players) volunteered at spring training. Bilateral shoulder IR and ER isometric strength was measured in sitting with the arm at the side using a handheld dynamometer stabilized on a wall via a specialized jig. Strength was normalized to body weight, and compared using t-tests between player type and geographic area of origin (p < 0.05).ResultsPosition players had greater strength in ER, IR and ER:IR (ER:0.7-2.7N/kg; IR:1.3-3.8N/kg; ER:IR ratio 0.36-1.22) compared to pitchers (ER:0.5-2.5N/kg; IR:0.6- 4.2N/kg; ER:IR ratio 0.44-1.16) on the throwing arm. North American pitchers had lower ER [MD= -0.4 (95%CI:-0.7,-0.2);p=0.002] and IR [MD= -0.2 (95%CI:-0.4,-0.1);p=0.006] than Latin American pitchers on the throwing arm. There were no differences between geographic groups for position players.Discussion/ConclusionsPlayer position and geographic origin influence shoulder rotational strength values in professional baseball players. Position players have 14 – 20% higher ER and IR isometric strength than pitchers. Moreover, Latin American pitchers exhibited 11.8% greater ER strength and 16.7% greater IR strength as compared to North American pitchers. Normative values can be used to determine player deficits, declines in performance, and targets for return to play after injury.Level of EvidenceLevel II     

SIDELYING GLENOHUMERAL PASSIVE INTERNAL ROTATION RANGE OF MOTION VALUES IN A HEALTHY COLLEGIATE POPULATION

Purpose/Background:

The sleeper stretch is a common intervention prescribed for individuals with decreased glenohumeral internal rotation. Passive glenohumeral internal rotation (GHIR) when quantified in sidelying has been suggested to be a more reliable measure as compared to measurments performed in supine with the humerus abducted to 908. Recently, the sidelying position has also been proposed as an evaluative measure to quantify GHIR. Minimal work however has described mean GHIR values in sidelying. Therefore, the objective of this study was to establish preliminary mean passive GHIR values in sidelying for a healthy, college‐age population. Secondary purposes were to ascertain if mean values were affected by upper extremity dominance or sex.

Methods:

Using a standardized protocol, passive GHIR was measured using a digital inclinometer on the dominant and non‐dominant shoulders of 60 healthy, college‐age participants (32 female [20.66±1.15 years, 170.70±14.38 cm, 63.34±7.51 kg] and 28 male [21.50±1.40 years, 183.81±13.17 cm, 90.04±17.91 kg]).

Results:

The sidelying passive GHIR grand mean for all participants bilaterally was 50.4 ± 11.78. Mean passive GHIR values on the non‐dominant side (52.7 ± 10.28) were greater than those on the dominant side (48.0 ± 12.58) (p = 0.002). There was no difference when GHIR values were compared by sex (p = 0.327) and a significant interaction between UE dominance and sex was not apparent (p = 0.693).

Conclusions:

In a healthy college age population, these preliminary data suggest GHIR values are statistically greater on the non‐dominant side and that sex does not significantly affect GHIR measures in a sidelying position.

Level of Evidence:

Level 3c     

STRENGTH & FUNCTIONAL ASSESSMENT OF HEALTHY HIGH SCHOOL FOOTBALL PLAYERS: ANALYSIS OF SKILLED AND NON‐SKILLED POSITIONS

Background/Purpose

Identifying an athlete''s functional capacity is an important consideration in determining when to allow an athlete to return to competition following injury. Establishing normative data for lower extremity functional assessment is valuable for comparison when making decisions regarding the high school athlete returning to play after injury. Therefore, the purpose of this study was to compare functional performance and strength between American high school football players of both skilled and non‐skilled positions.

Methods

Forty‐nine high school football players (30 skilled; 19 non‐skilled) completed a single‐session of testing consisting of a Figure of 8 test (F‐8), single‐leg vertical jump (SLVJ), single‐leg broad jump (SLBJ), and isokinetic knee strength assessment. Pearson correlation coefficients were used to determine the relationships between the results of functional testing and isokinetic strength measures. Paired t‐tests were used to determine the differences in functional performance and isokinetic muscle strength between skilled and non‐skilled athletes.

Results

Knee extension peak torque/body weight (BW) was moderately correlated (p < .01) with SLBJ (r = .54‐.61), SLVJ (r = .39‐.48), and F‐8 run times (r = ‐.50) for all athletes. Similar relationships were observed between knee flexion peak torque/BW and SLBJ (r = .48‐.49), SLVJ (r = .28‐.46), and the F‐8 run times (r = .41‐.52) for all subjects. No differences were observed between groups when examining raw peak torque values for knee flexion and extension (p > .05), however, skilled players did demonstrate greater peak torque/BW ratios (p < .05) for both knee extension and knee flexion at 60 and 240 degrees/sec. Skilled players also displayed faster F‐8 times (9.4 sec ± .3; p < .01) and greater SLBJ (p < .05) on both the dominant (81.0 in ± 9.3) and non‐dominant (83.0 in ± 7.6) limbs (p < .01) when compared to non‐skilled players.

Conclusions

Overall, skilled football players displayed greater peak torque/BW ratios and functional performance when compared to non‐skilled players. Furthermore, isokinetic peak torque/BW appears to be related to functional performance. This relationship is affected by position, with skilled players showing a stronger association. Limb dominance did not influence these functional and strength metrics. It is recommended that clinicians and coaches consider the positional differences in strength and functional performance when managing patients and athletes.

Level of Evidence

4 – Cross‐sectional Case Series     

EFFECTS OF A SEASON OF SUBCONCUSSIVE CONTACT ON CHILD‐ SCAT3 SCORES IN 8‐12 YEAR‐OLD MALE ATHLETES

Background

Each year, over 173,000 children and adolescents visit emergency departments due to sports and recreation related concussions, an increase of 60% over the last decade due to the rise in the number of children participating in sport. While numerous authors have sought to address the epidemiology of concussions across multiple age groups who participate in contact sports, a recent review of literature did not reveal a substantial amount of published articles that addressed the issue of subconcussive contact. Multiple tools have been developed to assess acute episodes of concussion. Among the assessment protocols many include an assessment of balance, short and long term memory recall, and balance. The Child‐SCAT3 was designed specifically to evaluate concussions in children 5‐12 years of age.

Objective

The purpose of this study was to determine the effect of a season of subconcussive contact on Child‐SCAT3 scores in 8‐12 year old males compared to their age matched peers who participated in non‐contact sports. A secondary purpose was to evaluate how scores of the sub‐ components of the Child‐SCAT3 compare between contact and non‐contact athletes.

Design

A prospective cohort study was performed of 71 male athletes (58 football, 13 baseball) ages 8‐12 (contact mean age 10.30 years, SD 1.20; non‐contact mean age 10.03 years, SD 1.26) over the course of a season.

Methods

Portions of The Child‐SCAT3 were administered and scored in pre‐adolescent athletes prior to and following a season of participation in football (contact sport group) and baseball (non‐contact sport group). The outcome measures of interest included the portions related to Cognitive ability, Balance, and Coordination.

Results

No statistically significant differences were found in group, time or time and group interaction for any of the utilized portions of the Child‐SCAT3. Statistically significant differences were found between groups for preseason cognitive orientation and postseason immediate memory. Cognitive orientation and coordination were also found to be statistically significantly improved across both groups over the course of the season.

Limitations

This study was potentially limited by the number of control subjects tested.

Conclusions

A season of subconcussive contact in football was not detrimental to cognitive and balance scores on the Child‐SCAT3.

Level of Evidence

3