OFF‐SEASON TRAINING HABITS AND PRESEASON FUNCTIONAL TEST MEASURES OF DIVISION III COLLEGIATE ATHLETES: A DESCRIPTIVE REPORT

Purpose/Background:

Division III (D III) collegiate coaches are challenged to assess athletic readiness and condition their athletes during the preseason. However, there are few reports on off‐season training habits and normative data of functional assessment tests among D III athletes. The purpose of this study was to examine off‐season training habits of D III athletes and their relationships to the standing long jump (SLJ) and single‐leg hop (SLH) tests.

Methods:

One‐hundred and ninety‐three athletes (110 females, age 19.1 ± 1.1 y; 83 males, age 19.5 ± 1.3 y) were tested prior to the start of their sports seasons. Athletes reported their off‐season training habits (weightlifting, cardiovascular exercise, plyometric exercise, and scrimmage) during the six weeks prior to the preseason. Athletes also performed three maximal effort SLJs and three SLHs.

Results:

Male athletes reported training more hours per exercise category than their female counterparts. Mean SLJ distances (normalized to height) were 0.79 ± 0.10 for females and 0.94 ± 0.12 for males. Mean SLH distances for female athletes'' right and left limbs were 0.66 (± 0.10) and 0.65 (± 0.10), respectively. Mean SLH distances for male athletes'' right and left limbs were 0.75 (± 0.13) and 0.75 (± 0.12), respectively. Several significant differences between off‐season training habits and functional test measures were found for both sexes: males [SLJ and weightlifting (p = 0.04); SLH and weightlifting (p = 0.04), plyometrics (p = 0.05)]; females [SLJ and plyometrics (p = 0.04); SLH and scrimmage (p = 0.02)].

Conclusion:

This study provides normative data for off‐season training habits and preseason functional test measures in a D III athlete population. Greater SLJ and SLH measures were associated with increased time during off‐season training.

Clinical Relevance:

The findings between functional tests and off‐season training activities may be useful for sports medicine professionals and strength coaches when designing their preseason training programs.

Level of Evidence:

4     

SUSTAINED ISOMETRIC SHOULDER CONTRACTION ON MUSCULAR STRENGTH AND ENDURANCE: A RANDOMIZED CLINICAL TRIAL

Background

The Advanced Throwers Ten Exercise Program incorporates sustained isometric contractions in conjunction with dynamic shoulder movements. It has been suggested that incorporating isometric holds may facilitate greater increases in muscular strength and endurance. However, no objective evidence currently exists to support this claim.

Hypothesis/Purpose

The purpose of this research was to compare the effects of a sustained muscle contraction resistive training program (Advanced Throwers Ten Program) to a more traditional exercise training protocol to determine if increases in shoulder muscular strength and endurance occur in an otherwise healthy population. It was hypothesized that utilizing a sustained isometric hold during a shoulder scaption exercise from the Advanced Throwers Ten would produce greater increases in shoulder strength and endurance as compared to a traditional training program incorporating a isotonic scapular plane abduction (scaption) exercise.

Study Design

Randomized Clinical Trial.

Method

Fifty healthy participants were enrolled in this study, of which 25 were randomized into the traditional training group (age: 26 ± 8, height:172 ± 10 cm, weight: 73 ± 13 kg, Marx Activity Scale: 11 ± 4) and 25 were randomized to the Advanced Throwers Ten group (age: 28 ± 9, height: 169 ± 23 cm, weight: 74 ± 16 kg, Marx Activity Scale: 11 ± 5). No pre‐intervention differences existed between the groups (P>0.05). Arm endurance and strength data were collected pre and post intervention using a portable load cell (BTE Evaluator, Hanover, MD). Both within and between group analyses were done in order to investigate average torque (strength) and angular impulse (endurance) changes.

Results

The traditional and Advanced Throwers Ten groups both significantly improved torque and angular impulse on both the dominant and non‐dominant arms by 10–14%. There were no differences in strength or endurance following the interventions between the two training groups (p>0.75).

Conclusions;

Both training approaches increased strength and endurance as the muscle loads were consistent between protocols indicating that either approach will have positive effects.

Level of Evidence

Level 2     

INTRA AND INTERSESSION RELIABILITY OF A POSTURAL CONTROL PROTOCOL IN ATHLETES WITH AND WITHOUT ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION: A DUAL‐TASK PARADIGM

Background:

Quantification of dynamic balance is essential to assess a patient''s level of injury or ability to function so that a proper plan of care may commence. In spite of comprehensive utilization of dual‐tasking in balance assessment protocols, a lack of sufficient reliability data is apparent.

Purpose:

The purpose of the present study was to determine the intra‐ and inter‐session reliability of dynamic balance measures obtained using the Biodex Balance System® (BBS) for a group of athletes who had undergone anterior cruciate ligament reconstruction (ACLR) and a matched control group without ACLR, while using a dual‐task paradigm.

Methods:

Single‐limb postural stability was assessed in 15 athletes who had undergone ACLR and 15 healthy matched controls. The outcome variables included measures of both postural and cognitive performance. For measuring postural performance, the overall stability index (OSI), anterior‐posterior stability index (APSI), and medial‐lateral stability index (MLSI), were recorded. Cognitive performance was evaluated by measuring error ratio and average reaction time. Subjects faced 4 postural task difficulty levels (platform stabilities of 8 and 6 with eyes open and closed), and 2 cognitive task difficulty levels (with or without auditory Stroop task). During dual task conditions (conditions with Stroop task), error ratio and average reaction time were calculated.

Results:

Regarding intrasession reliability, ICC values of test session were higher for MLSI [ACL‐R group (0.83‐0.95), control group (0.71‐0.95)] compared to OSI [ACL‐R group (0.80‐0.92), control group (0.67‐0.95)] and APSI [ACL‐R group (0.73‐0.90), control group (0.62‐0.90)]. Furthermore, ICC values of first test session were higher in reaction time [ACL‐R group (0.92‐0.95), control group (0.80‐0.92)] than error ratio [ACL‐R group (0.72‐0.88), control group (0.61‐0.83)]. ICC values of retest session were higher for MLSI [ACL‐R group (0.83‐0.94), control group (0.87‐0.93)] than OSI [ACL‐R group (0.81‐0.91), control group (0.83‐0.93)] and APSI [ACL‐R group (0.73‐0.90), control group (0.53‐0.90)]. Moreover, ICC values of retest session were higher in reaction time [ACL‐R group (0.89‐0.98), control group (0.80‐0.92)] equated with error ratio [ACL‐R group (0.73‐0.87), control group (0.57‐0.79)].With respect to intersession reliability, ICC values were higher for MLSI [ACL‐R group (0.72‐0.96), control group (0.75‐0.92)] than OSI [ACL‐R group (0.55‐0.91), control group (0.64‐0.87)] and APSI [ACL‐R group (0.55‐0.79), control group (0.46‐0.89)]. Additionally, ICC values were higher in reaction time [ACL‐R group (0.87‐0.95), control group (0.68‐0.81)] in contrast to error ratio [ACL‐R group (0.42‐0.64), control group (0.54‐0.74)].

Conclusion:

Biodex Balance System® measures of postural stability demonstrated moderate to high reliability in athletes with and without ACLR during dual‐tasking. Results of the current study indicated that assessment of postural and cognitive performance in athletes with ACLR may be reliably incorporated into the evaluation of functional activity.

Level of Evidence:

2b     

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     

COMPARISON OF ECCENTRIC AND CONCENTRIC EXERCISE INTERVENTIONS IN ADULTS WITH SUBACROMIAL IMPINGEMENT SYNDROME

Background

Researchers have demonstrated moderate evidence for the use of exercise in the treatment of subacromial impingement syndrome (SAIS). Recent evidence also supports eccentric exercise for patients with lower extremity and wrist tendinopathies. However, only a few investigators have examined the effects of eccentric exercise on patients with rotator cuff tendinopathy.

Purpose

To compare the effectiveness of an eccentric progressive resistance exercise (PRE) intervention to a concentric PRE intervention in adults with SAIS.

Study Design

Randomized Clinical Trial

Methods

Thirty‐four participants with SAIS were randomized into concentric (n = 16, mean age: 48.6 ± 14.6 years) and eccentric (n = 18, mean age: 50.1 ± 16.9 years) exercise groups. Supervised rotator cuff and scapular PRE''s were performed twice a week for eight weeks. A daily home program of shoulder stretching and active range of motion (AROM) exercises was performed by both groups. The outcome measures of the Disabilities of the Arm, Shoulder, and Hand (DASH) score, pain‐free arm scapular plane elevation AROM, pain‐free shoulder abduction and external rotation (ER) strength were assessed at baseline, week five, and week eight of the study.

Results

Four separate 2x3 ANOVAs with repeated measures showed no significant difference in any outcome measure between the two groups over time. However, all participants made significant improvements in all outcome measures from baseline to week five (p <  0.0125). Significant improvements also were found from week five to week eight (p < 0.0125) for all outcome measures except scapular plane elevation AROM.

Conclusion

Both eccentric and concentric PRE programs resulted in improved function, AROM, and strength in patients with SAIS. However, no difference was found between the two exercise modes, suggesting that therapists may use exercises that utilize either exercise mode in their treatment of SAIS.

Level of evidence

Therapy, level 1b     

Y BALANCE TEST? ANTERIOR REACH SYMMETRY AT THREE MONTHS IS RELATED TO SINGLE LEG FUNCTIONAL PERFORMANCE AT TIME OF RETURN TO SPORTS FOLLOWING ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

Background

Restoration of symmetrical strength, balance, and power following anterior cruciate ligament reconstruction (ACL‐R) are thought to be important factors for successful return to sports. Little information is available regarding early rehabilitation outcomes and achieving suggested limb indices of 90% on functional performance measures at the time of return to sports (RTS).

Hypothesis/Purpose

To examine the relationship between symmetry of the anterior reach of the Y Balance Test™ at 12 weeks and functional performance measures at time of return to sports after anterior cruciate ligament (ACL) reconstruction.

Study Design

Retrospective Cohort

Methods

Forty subjects (mean ± SD age, 17.2 ± 3.8 years) who were in the process of rehabilitation following ACL reconstruction. Each subject volunteered and was enrolled in the study during physical therapy following ACL‐R. Participants averaged two visits per week in physical therapy until the time of testing for RTS. The Y Balance Test™ was assessed at 12 weeks. Participants completed a battery of tests at RTS (6.4 ± 1.1 months) including triple hop distance (THD), single hop distance (SHD), isometric knee extension strength (KE), and the Vail Sport Test™. Side to side difference was calculated for the Y Balance Test™ anterior reach and limb symmetry indices (LSI) were computed for THD, SHD, and KE. Multiple regression models were used to study the relationship between variables at 12 weeks and RTS while controlling for age, gender, type of graft, and pain score. In addition, subjects were dichotomized based on a side‐to‐side Y Balance anterior reach difference into high risk (>4 cm) or low risk (≤4 cm) categories. A receiver operating characteristic (ROC) curve was used to identify individuals at 12 weeks who do not achieve 90% limb symmetry indices at time of RTS testing. .

Results

A statistically significant association was seen between Y Balance ANT at 12 weeks and SHD at RTS (β = −1.46, p = 0.0005, R² = 0.395), THD at RTS (β = −1.08, p = 0.0011, R² = 0.354) and KE at RTS (β = −1.00, p = 0.0025, R² = 0.279) after adjusting for age, gender, type of graft and pain score at week 12. There was no significant association between Y Balance ANT at 12 weeks and Vail Sport Test at RTS (p = 0.273). ROC curves indicated that the Y Balance ANT at 12 weeks identified participants who did not achieve 90% LSI for the SHD (AUC = 0.82 p = 0.02) and THD (AUC=0.85, p = 0.01) at RTS with a sensitivity of 0.96 (SHD) and 0.92 (THD) respectively.

Conclusions

Participants following ACL‐R who demonstrated > 4 cm Y Balance ANT deficits at 12 weeks on their involved limb did not tend to achieve 90% LSI for the SHD and THD at time of return to sports. The Y Balance ANT at 12 weeks and Vail Sport Test™ appear to measure different constructs following ACL‐R.

Levels of Evidence

Level 3     

SPORTSMETRICS? TRAINING IMPROVES POWER AND LANDING IN HIGH SCHOOL ROWERS

Background

Successful rowing participation requires leg power, back strength, cardiovascular endurance, and balance. SportsMetrics™ training improves lower limb alignment, hamstring peak torque, and vertical jump height; however, this training has not been used in athletes who row and may have different outcomes based on experience level.

Purpose/Hypotheses

The purpose of this study was to compare the effects of a six-week SportsMetrics™ training program on vertical jump height (VJH), Y Balance Test (YBT), and Drop Jump Screening Test (DJST) between novice and varsity high school rowers. The authors hypothesized that following Sportsmetrics™ training; novice rowers would not be different from varsity rowers in VJH and YBT. All rowers will have improved normalized knee joint separation distance in DJST following training.

Study Design

Cross sectional.

Methods

52 (31 varsity: 16.4 ± 0.8 years, 62.0 ± 9.0 kg, 1.7 ± 0.1m [mean ± SD], 21 novice: 14.5 ± 0.7years, 58.6 ± 5.4 kg, 1.7 ± 0.1m [mean ± SD]) high school rowers completed the Sportsmetrics™ training and participated in the study. Varsity rowers were defined as a returner; any new rower was considered novice. Differences in age, weight, and height were examined using independent t-tests. Repeated measures ANOVA assessed pre- to post-training differences between groups in VJH, YBT composite score (CS) and reach asymmetry (ASY), and normalized knee joint separation distance (DJST).

Results

VJH significantly improved for all athletes from pre- to post-training (mean ± SD: 29.0 ± 7.0 vs. 31.9 ± 5.1cm; p=0.001) and normalized knee separation distance significantly increased for all athletes pre to post training at the pre-landing (mean ± SD: 58.2 ± 12.5 vs. 68.7 ± 7.4%; p<0.001), landing (mean ± SD: 49.4 ± 18.2 vs. 66.3 ± 14.2%; p<0.001), and take off (mean ± SD: 47.8 ± 18.4 vs. 64.8 ± 13.8%; p<0.001) phases of the jump; there was no effect for group. There was no difference in varsity and novice pre to post training in YBT CS (99.3 ± 7.5 vs. 99.7 ± 7.1%; p=0.53) or ANT ASY (mean ± SD: 3.4 ± 4.6 vs. 2.7 ± 2.3; p=0.36).

Conclusions

SportsMetrics™ training improved VJH regardless of experience level; which suggests that rowers may have more leg power following training. Normalized knee joint separation distance increased to greater than 60% of hip joint separation distance following training, indicating that training reduced serious knee injury risk.

Level of Evidence

Level 3     

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     

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     

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     

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     

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     

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     

IMMEDIATE EFFECTS OF A DYNAMIC ROTATION‐SPECIFIC WARM‐UP ON X‐FACTOR AND X‐FACTOR STRETCH IN THE AMATEUR GOLFER

Background

Recent evidence suggests performing a warm‐up prior to golf can improve performance and reduce injuries. While some characteristics of effective golf warm‐ups have been determined, no studies have explored the immediate effects of a rotational‐specific warm‐up with elements of motor control on the biomechanical aspects of the full X‐Factor and X‐Factor Stretch during the golf swing.

Methods

Thirty‐six amateur golfers (mean ± SD age: 64 ± 8 years old; 75% male) were randomized into a Dynamic Rotation‐Specific Warm‐up group (n=20), or a Sham Warm‐up group (n=16). X‐Factor and X‐Factor Stretch were measured at baseline and immediately following the warm‐up. Mixed model ANCOVAs were used to determine if a Group*Time interaction existed for each variable with group as the between‐subjects variable and time as the within‐subjects variable.

Results

The mixed model ANCOVAs did not reveal a statistically significant group*time interaction for X‐Factor or X‐Factor Stretch. There was not a significant main effect for time for X‐Factor but there was for X‐Factor Stretch. These results indicate that neither group had a significant effect on improving X‐Factor, however performing either warm‐up increased X‐Factor Stretch without significant difference between the two.

Conclusions

The results of this study suggest that performing the Dynamic Rotation‐Specific Warm‐up did not increase X‐Factor or X‐Factor Stretch when controlled for age compared to the Sham Warm‐up. Further study is needed to determine the long‐term effects of the Dynamic Rotation‐Specific Warm‐up on performance factors of the golf swing while examining across all ages.

Level of Evidence

2b     

MODIFIED FUNCTIONAL MOVEMENT SCREENING AS A PREDICTOR OF TACTICAL PERFORMANCE POTENTIAL IN RECREATIONALLY ACTIVE ADULTS

Background

Failure to meet minimum performance standards is a leading cause of attrition from basic combat training. A standardized assessment such as the Functional Movement Screen™ (FMS™) could help identify movement behaviors relevant to physical performance in tactical occupations. Previous work has demonstrated only marginal association between FMS™ tests and performance outcomes, but adding a load challenge to this movement assessment may help highlight performance‐limiting behaviors.

Purpose

The purposes of this investigation were to quantify the effect of load on FMS™ tests and determine the extent to which performance outcomes could be predicted using scores from both loaded and unloaded FMS™ conditions.

Study Design

Crossover Trial.

Methods

Thirteen female and six male recreationally active college students (21 ± 1.37 years, 168 ± 9.8 cm, 66 ± 12.25 kg) completed the FMS™ under (1) a control condition (FMS™_C), and (2) an 18.10kg weight vest condition (FMS™_W). Balance was assessed using a force plate in double‐legged stance and tactical physical performance was evaluated via completion times in a battery of field tests. For each condition, penalized regression was used to select models from the seven FMS™ component tests to predict balance and performance outcomes. Data were collected during a single session lasting approximately three hours per participant. Results: For balance, significant predictors were identified from both conditions but primarily predicted poorer balance with increasing FMS™ scores. For tactical performance, models were retained almost exclusively from FMS™_W and generally predicted better performance with higher item scores.

Conclusions

The current results suggest that FMS™ screening with an external load could help predict performance relevant to tactical occupations. Sports medicine and fitness professionals interested in performance outcomes may consider assessing movement behaviors under a load.

Level of Evidence

3