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     

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     

RELIABILITY OF THE MYOTONOMETER FOR ASSESSMENT OF POSTERIOR SHOULDER TIGHTNESS

Background/Purpose:

The Myotonometer® is an electronic tissue compliance meter that has been used to quantify the compliance of soft tissues. The Myotonometer® may be a valuable tool to measure the effectiveness of interventions commonly used to increase tissue compliance in individuals with posterior shoulder tightness (PST). Limited data exist on reliability and responsiveness of the Myotonometer® for assessment of soft tissues about the shoulder; therefore, the purpose of this study is to determine the intra‐ and inter‐session reliability and responsiveness of the Myotonometer® in measuring tissue compliance of the posterior shoulder musculature in asymptomatic subjects with PST.

Methods:

Fifteen asymptomatic subjects with unilateral shoulder range of motion deficits attended two measurement sessions to assess the compliance of the tissues overlying the posterior deltoid, infraspinatus, and teres musculature. Analyses of reliability and responsiveness were conducted using intra‐class correlation coefficients (ICCs) and the determination of minimal detectible change (MDC).

Results:

Intra‐session ICC values ranged from 0.69 to 0.91 for all muscles with MDC never exceeding 1.0 mm. Inter‐session ICC values were best for the posterior deltoid, which averaged 0.82, compared to the infraspinatus and the teres complex, which averaged 0.42 and 0.5 respectively. Inter‐session MDC ranged from 0.55 to 1.20 mm across all muscles.

Conclusions:

Clinicians can reliably detect relatively small changes in tissue compliance within a single treatment session utilizing the Myotonometer®. The Myotonometer® can reliably detect changes between sessions for tissues overlying the posterior deltoid; however, observed change in the infraspinatus and teres musculature must be above 1 mm to achieve meaningful change and account for decreased inter‐session reliability.

Level of Evidence:

3     

EFFECT OF RESTRICTED HIP FLEXOR MUSCLE LENGTH ON HIP EXTENSOR MUSCLE ACTIVITY AND LOWER EXTREMITY BIOMECHANICS IN COLLEGE‐AGED FEMALE SOCCER PLAYERS

Background

Hip flexor tightness is theorized to alter antagonist muscle function through reciprocal inhibition and synergistic dominance mechanisms. Synergistic dominance may result in altered movement patterns and increased risk of lower extremity injury.

Hypothesis/Purpose

To compare hip extensor muscle activation, internal hip and knee extension moments during double‐leg squatting, and gluteus maximus strength in those with and without clinically restricted hip flexor muscle length.

Design

Causal‐comparative cross‐sectional laboratory study.

Method

Using a modified Thomas Test, female soccer athletes were assigned to a restricted (>0 ° of sagittal plane hip motion above the horizontal; n=20, age=19.9 ± 1 years, ht=167.1 ± 6.4 cm, mass=64.7 ± 8.2kg) or normal (>15 ° of sagittal plane hip motion below horizontal; n=20, age=19.4 ± 1 years, ht=167.2 ± 5.5 cm, mass=61.2 ± 8.6 kg) hip flexor muscle length group. Surface electromyographic (sEMG) activity of the gluteus maximus and biceps femoris, and net internal hip and knee extension moments were measured between groups during a double‐leg squat. Isometric gluteus maximus strength was assessed using handheld dynamometry.

Results

Individuals with restricted hip flexor muscle length demonstrated less gluteus maximus activation (p=0.008) and a lower gluteus maximus : biceps femoris co‐activation ratio (p=0.004). There were no significant differences (p>0.05) in hip or knee extension moments, isometric gluteus maximus strength, or biceps femoris activation between groups.

Conclusions

Female soccer athletes with hip flexor muscle tightness exhibit less gluteus maximus activation and lower gluteus maximus : biceps femoris co‐activation while producing similar net hip and knee extension moments. Thus, individuals with hip flexor muscle tightness appear to utilize different neuromuscular strategies to control lower extremity motion.

Level of Evidence

3     

EFFECTS OF POSTURAL CONTROL MANIPULATION ON VISUOMOTOR TRAINING PERFORMANCE: COMPARATIVE DATA IN HEALTHY ATHLETES

Purpose/Background:

Visuomotor ability is an important parameter for neurologic function and effective sport performance. Adding a balance challenge during a structured eye‐hand coordination task, such as hitting lights on a light board (Dynavision™), has not been previously reported. Using Division I football players, the aim of this study was to determine normative data on a dual‐task performance regimen combining a visuomotor light board task with a balance task. The intent is to use such normative data and baseline data as part of a concussion management program.

Methods:

Division I college football team members, n=105, were consented. Subjects first performed Dynavision™ D2™ Visuomotor Training Device (D2™) eye‐hand coordination tasks, the A* and the RT; they then performed the same tasks with an added balance challenge, standing on a BOSU® ball.

Results:

Ninety‐four athletes completed the full testing procedure on the D2™ system. The mean score of the A* test was 93 ± 11.0 hits per minute; and the mean on the A* test with the added BOSU® balance challenge was 83.7 ± 9.2 hits per minute. The mean RT time was 0.33 ± 0.036 seconds. Mean reaction time increased to 0.38 ± 0.063 while the subject stood on the BOSU® ball. Performance on the D2™ A* and RT were both statistically significantly different in the dual task condition (p<0.05).

Conclusions:

Results show an approximate 10% decline in D2™ performance when healthy individuals stand on a BOSU® ball. From the data presented here, the authors determined that there is a 10% decrement in performance when one''s balance is challenged on the BOSU® ball. A fall in performance of substantially greater than 10% may indicate abnormal vestibulocerebellar regulatory processing of balance and motion. Further research, using these normative data is needed to determine more specific parameters for definitions of impairment and return‐to‐play and if there is utility for such studies as part of a concussion management program.

Level of Evidence:

III     

COMPARISON OF THE EFFECTS OF AN EIGHT‐WEEK PUSH‐UP PROGRAM USING STABLE VERSUS UNSTABLE SURFACES

Background and Purpose:

Recently, the trend among physical training and rehabilitation professionals is the use of resistance exercise on unstable equipment in order to increase the effort of the agonist and stabilizing muscles. It is unknown if performing exercises on unstable surfaces provides a greater training stimulus as compared to training on a stable training surface. Therefore, the purpose of this research was to compare the effect that push‐up training on stable and unstable surfaces had on strength performance in healthy young men.

Methods:

Thirty subjects with experience in resistance training participated in push‐up training two days per week for eight weeks on one of three different surfaces: the floor (Tp), the T‐Bow® (TBp) or the BOSU® (Bp).

Results:

Strength, as measured by one repetition maximum (1‐RM) and muscle endurance, as measured by number of pushups performed did not improve significantly (p>0.05) for any of the intervention groups.

Conclusions:

The addition of unstable surfaces in push‐up training does not provide greater improvement in muscular strength and endurance than push up training performed on a stable surface in young men.

Levels of Evidence:

3b     

TEST‐RETEST RELIABILITY OF TETRAX? STATIC POSTUROGRAPHY SYSTEM IN YOUNG ADULTS WITH LOW PHYSICAL ACTIVITY LEVEL

Purpose/Background

Assessment of postural sway with force plates can be affected by type of measurement and various clinical parameters such as age and activity level of the individual person. For this reason, variability is detected in postural reactions of healthy subjects without balance impairment. Test‐retest reliability of postural sway in adolescent athletes has been measured using a force plate and additional test‐retest studies have been suggested for subjects of different age groups with different activity levels. Therefore, the purpose of this research was to assess test‐retest reliability of Tetrax® Static Posturography in young adults with low physical activity level, and examine the relationship between posturography results and low activity level.

Methods

Young adults older than 18 years of age were included in the study. Demographic characteristics of the cases were recorded including age, weight, height, body mass index (BMI, kg/m2) and dominant extremity. Number of falls in the previous six months, lower body endurance (sit to stand test) and single‐leg eyes closed stance test were recorded. Activity level of participants was determined according to the International Physical Activity Questionnaire (IPAQ). Posturographic evaluation of all volunteers was completed using the Tetrax® Interactive Postural Balance System (Sunlight Medical Ltd, Israel). Fall risk and general stability index (SI) calculated by the Tetrax® were recorded. Following the first test, measurements were repeated 24 to 48 hours later for reliability purposes.

Results

Sixty‐five subjects (28 male, 37 female; mean age 22.2 ± 1.1 years, mean BMI 22.6 ± 3.3 kg/m²) were evaluated. All participants were classified as minimally active according to mean IPAQ score (1042.1 ± 517.7 [231 – 2826] MET‐ minutes per week). ICC scores between the first and second tests for fall index and total stability index were excellent (ICC_2,1=0.858, 0.850, respectively). Fall risk determined by using the Tetrax® device was negatively correlated with lower body endurance (p=0.001, r=‐0.446), vigorous activity score (p=0.011, ‐0.312) and total activity score (p=0.029, r=‐0.271), and positively correlated with single leg stance score (p=0.001, r=0.606). There was a weak correlation between fall risk history and the fall risk determined by using Tetrax® device (p=0.04, r=0.255). There were no correlations between fall risk and height, weight, and BMI (p>0.05).

Conclusions

The results demonstrated the high test‐retest reliability of Tetrax® interactive balance system in young healthy adults with low physical activity level. Future studies are needed to determine the effectiveness of increasing physical activity level on postural control.

Level of Evidence

III     

INFLUENCE OF PATTERNED ELECTRICAL NEUROMUSCULAR STIMULATION ON QUADRICEPS ACTIVATION IN INDIVIDUALS WITH KNEE JOINT INJURY

Background:

Neuromuscular Electrical Stimulation is a common intervention to address muscle weakness, however presents with many limitations such as fatigue, muscle damage, and patient discomfort that may influence its effectiveness. One novel form of electrical stimulation purported to improve neuromuscular re‐education is Patterned Electrical Neuromuscular Stimulation (PENS), which is proposed to mimic muscle‐firing patterns of healthy individuals. PENS provides patterned stimulating to the agonist muscle, antagonist muscle and then agonist muscle again in an effort to replicate firing patterns.

Purpose:

The purpose of this study was to determine the effect of a single PENS treatment on knee extension torque and quadriceps activation in individuals with quadriceps inhibition.

Methods:

18 subjects (10 males and 8 females: 24.2±3.4 years, 175.3±11.8cm, 81.8±12.4kg) with a history of knee injury/pain participated in this double‐blinded randomized controlled laboratory trial. Participants demonstrated quadriceps inhibition with a central activation ratio of ≤90%. Maximal voluntary isometric contraction of the quadriceps and central activation ratio were measured before and after treatment. The treatment intervention was a 15‐minute patterned electrical stimulation applied to the quadriceps and hamstring muscles with a strong motor contraction or a sham group, who received an identical set up as the PENS group, but received a 1mA subsensory stimulation. A 2×2 (group × time) ANCOVA was used to determine differences in maximal voluntary isometric contraction and central activation ratio between groups. The maximal voluntary isometric contraction was selected as a covariate due to baseline differences.

Results:

There were no differences in change scores between pre‐ and post‐intervention for maximal voluntary isometric contraction: (PENS: 0.09±0.32Nm/kg and Sham 0.15±0.18Nm/kg, p=0.713), or central activation ratio:(PENS: ‐1.22±6.06 and Sham: 1.48±3.7, p=0.270).

Conclusions:

A single Patterned Electrical Neuromuscular Stimulation treatment did not alter quadriceps central activation ratio or maximal voluntary isometric contraction. Unlike other types of muscle stimulation, PENS did not result in a reduction of quadriceps torque.

Level of Evidence:

Level III     

EVIDENCE FOR ISOKINETIC KNEE TORQUE ASYMMETRIES IN MALE LONG DISTANCE‐TRAINED RUNNERS

Purpose/Background

Strength asymmetries are related to knee injuries and such injuries are frequently observed among runners. The purpose of this study was to examine whether long‐distance runners have symmetric performance during knee isokinetic testing at two angular velocities.

Methods

Twenty‐three healthy and well‐trained male long‐distance runners performed open‐chain isokinetic trials for assessment of concentric quadriceps and hamstrings contractions at velocities of 60 °·s^‐1 and 240 °·s^‐1. Data were compared between the lower limbs at different velocities.

Results

Peak torque and total work were similar between the limbs. Asymmetry was observed for knee flexor power at 240 °·s^‐1 (237 ± 45 W and 205 ± 53 W, in the preferred and non‐preferred limb, respectively). Asymmetry indexes for flexor power were different between the velocities tested (13.1% and 2.21% for 240 °·s^‐1 and 60 °·s^‐1, respectively).

Conclusion

A limb asymmetry was observed among runners for knee flexor power, mainly at higher angular velocities (240 °·s^‐1). In addition, H/Q ratios were observed to be contraction velocity dependent.

Level of Evidence

3     

THE RELATIONSHIP BETWEEN PASSIVE GLENOHUMERAL TOTAL ROTATION AND THE STRENGTH OF THE INTERNAL AND EXTERNAL ROTATOR MUSCLES,A PRELIMINARY STUDY

Background

There is little research on how the amount of shoulder joint range of motion, specifically glenohumeral rotation, may be related to the muscle strength of the rotator cuff muscles. A long held belief is that a joint with excessive range of motion needs sufficient muscular strength for stability. However, no studies have examined this concept.

Purpose

The purpose of this study was to see if total arc of glenohumeral joint rotation (External rotation [ER]+Internal rotation [IR]) could predict peak isometric muscle strength of the IR or ER muscles of the shoulder.

Study Design

Cross‐sectional study design

Methods

Fifty‐three participants (41 females, 12 males) participated in the study. Passive glenohumeral joint internal rotation and external rotation motion was measured for each participant with a standard goniometer. Isometric muscle force of the ER and IR muscles were tested using a handheld dynamometer in three positions: end range ER, neutral 0°, and end range IR. Data were analyzed using a non‐parametric tree based regression method (CART) and then cross‐validated.

Results

The results showed that those with an increased total arc of motion of glenohumeral rotation (greater than 165.0°) had less muscle isometric muscle strength in all tests positions than those with less glenohumeral rotation.

Conclusion

Decreased force of the ER and IR muscles of the shoulder was noted in those with increased total arc glenohumeral rotation ( > 165.0°), specifically those with increased glenohumeral internal rotation ( > 80.0°) when compared to those with glenohumeral rotation ( < 165.0°) and glenohumeral internal rotation ( < 80.0°). Future studies should include more males and attempt to develop strategies to assist those with larger excursions of shoulder rotation who may be at risk of developing shoulder problems.

Level of Evidence

Level 2     

QUANTIFYING FRONTAL PLANE KNEE MOTION DURING SINGLE LIMB SQUATS: RELIABILITY AND VALIDITY OF 2‐DIMENSIONAL MEASURES

Background:

Clinical assessment of lower limb kinematics during dynamic tasks may identify individuals who demonstrate abnormal movement patterns that may lead to etiology of exacerbation of knee conditions such as patellofemoral joint (PFJt) pain.

Purpose:

The purpose of this study was to determine the reliability, validity and associated measurement error of a clinically appropriate two‐dimensional (2‐D) procedure of quantifying frontal plane knee alignment during single limb squats.

Methods:

Nine female and nine male recreationally active subjects with no history of PFJt pain had frontal plane limb alignment assessed using three‐dimensional (3‐D) motion analysis and digital video cameras (2‐D analysis) while performing single limb squats. The association between 2‐D and 3‐D measures was quantified using Pearson''s product correlation coefficients. Intraclass correlation coefficients (ICCs) were determined for within‐ and between‐session reliability of 2‐D data and standard error of measurement (SEM) was used to establish measurement error.

Results:

Frontal plane limb alignment assessed with 2‐D analysis demonstrated good correlation compared with 3‐D methods (r = 0.64 to 0.78, p < 0.001). Within‐session (0.86) and between‐session ICCs (0.74) demonstrated good reliability for 2‐D measures and SEM scores ranged from 2° to 4°.

Conclusion:

2‐D measures have good consistency and may provide a valid measure of lower limb alignment when compared to existing 3‐D methods.

Clinical Relevance:

Assessment of lower limb kinematics using 2‐D methods may be an accurate and clinically useful alternative to 3‐D motion analysis when identifying individuals who demonstrate abnormal movement patterns associated with PFJt pain.

Level of Evidence:

2b     

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     

AN ELECTROMYOGRAPHIC ANALYSIS OF THE SHOULDER COMPLEX MUSCULATURE WHILE PERFORMING EXERCISES USING THE BODYBLADE? CLASSIC AND BODYBLADE? PRO

Background

In spite of the bodyblade (BB®) being used in clinical settings during shoulder and trunk rehabilitation and training for 24 years, there are only five known scientific papers that have described muscle recruitment patterns using the BB®. Moreover, there are no known studies that have examined muscle activity differences between males and females (who both use the bodyblade in the clinic) or between different BB® devices.

Hypothesis/Purpose

The primary purposes of this investigation were to compare glenohumeral and scapular muscle activity between the Bodyblade® Pro (BB®P) and Bodyblade® Classic (BB®C) devices while performing a variety of exercises, as well as to compare muscle activity between males and females. It was hypothesized that glenohumeral and scapular muscle activity would be significantly greater in females compared to males, significantly greater while performing exercises with the BB®P compared to the BB®C, significantly different among various BB® exercises, and greater with two hand use compared to one hand use for the same exercise.

Study Design

Controlled laboratory study using a repeated-measures, counterbalanced design.

Methods

Twenty young adults, 10 males and 10 females, performed seven BB® exercises using the BB®C and BB®P, which are: 1) BB®1 - one hand, up and down motion, arm at side; 2) BB®2 - one hand, front to back motion, shoulder flexed 90 °; 3) BB®3 - one hand, up and down motion, shoulder abducted 90 °; 4) BB®4 - one hand, side to side motion, shoulder and elbow flexed 45 °; 5) BB®5 - two hands, side to side motion, shoulders and elbows flexed 45 °; 6) BB®6 - two hands, up and down motion, shoulders flexed 90 °; and 7) BB®7 - two hands, front to back motion, shoulders flexed 90 °. EMG data were collected from anterior and posterior deltoids, sternal pectoralis major, latissimus dorsi, infraspinatus, upper and lower trapezius, and serratus anterior during 10 sec of continuous motion for each exercise, and then normalized using maximum voluntary isometric contractions (MVIC). A two-factor repeated measures Analysis of Variance (p < 0.05) was employed to assess differences in EMG activity between BB® devices (BB®C and BB®P) and genders.

Results

As hypothesized, for numerous exercises and muscles glenohumeral and scapular EMG activity was significantly greater in females compared to males and was significantly greater in the BB®P compared to BB®C. There were generally no significant interactions between BB® devices and gender. Overall glenohumeral and scapular muscle activity was significantly greater in BB®3 and BB®6 compared to the remaining exercises, but generally not significantly different between using one hand and using two hands.

Conclusions

It may be appropriate to employ BB® exercises during shoulder rehabilitation earlier for males compared to females and earlier for the BB®C compared to the BB®P given less overall muscle activation in males and BB®C compared to in females and BB®P. There was generally no difference in muscle activity between performing the BB® with one-hand or two-hands. Differences in muscle activity between exercises generally was the similar regardless if the BB®C or the BB®P was employed.

Level of Evidence

Level 2     

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     

TEMPORAL PATTERN OF KINESIOLOGY TAPE EFFICACY ON HAMSTRING EXTENSIBILITY

Background

Kinesiology tape has been advocated as a means of improving muscle flexibility, a potential modifiable risk factor for injury, over time. The epidemiology and etiology of hamstring injuries in sport have been well documented.

Purpose

To compare the temporal pattern of efficacy of kinesiology tape and traditional stretching techniques on hamstring extensibility over a five day period.

Study Design

Controlled laboratory study.

Methods

Thirty recreationally active male participants (Mean ± SD: age 20.0 ± 1.55 years; height 179.3 ± 4.94 cm; mass 76.9 ± 7.57 kg) completed an active knee extension assessment (of the dominant leg) as a measure of hamstring extensibility. Three experimental interventions were applied in randomized order: Kinesiology tape (KT), static stretch (SS), proprioceptive neuromuscular facilitation (PNF). Measures were taken at baseline, +1min, + 30mins, + 3days and +5days days after each intervention. The temporal pattern of change in active knee extension was modelled as a range of regression polynomials for each intervention, quantified as the regression coefficient.

Results

Hamstring ROM with KT application at +3days was significantly greater than baseline (129.18 ± 15.46%, p = 0.01), SS (106.99 ± 9.84%, p = 0.03) and PNF (107.42 ± 136.13%, p = 0.03) interventions. The temporal pattern of changes in ROM for SS and PNF were best modelled by a negative linear function, although the strength of the correlation was weak in each case. In contrast, the KT data was optimised using a quadratic polynomial function (r² = 0.60), which yielded an optimum time of 2.76 days, eliciting a predicted ROM of 129.6% relative to baseline.

Conclusion

Each intervention displayed a unique temporal pattern of changes in active knee extension. SS was best suited to immediate improvements, and PNF to +30 minutes in hamstring extensibility, whereas kinesiology tape offered advantages over a longer duration, peaking at 2.76 days. These findings have implications for the choice of intervention, timing and duration to assist clinicians in both a sporting and clinical context.

Level of evidence

2c