HiPER Research Articles

Hip Abductor and External Rotator Strengths Correlate With Hop Symmetry in Men Athletes 2 Years After Anterior Cruciate Ligament Reconstruction.

Hip muscle strength and hop performance limb symmetries after anterior cruciate ligament reconstruction (ACLR) are not well studied. This study aimed to determine the differences in hip abductors' (ABD) and external rotators' (ER) muscle strength measures between limbs, and the relationship between hip ABD and ER muscle strengths and hop performance limb symmetry indices (LSIs) 2years after ACLR. Cross-sectional study. Forty (level I/II) men athletes 2years after unilateral ACLR completed 4 single-legged hop tests and involved hip ABD and ER strength testing (maximum voluntary isometric contraction [MVIC]; isokinetic peak torque [PKTQ] at 60°, 180°, and 300°/s; and isotonic peak velocity at 75% of their MVICs). Muscle strength measures were normalized to body mass, and hop performances were reported as LSIs. Paired t test was used to determine strength differences between limbs, and the Pearson correlation coefficient was used to assess the relationship between involved hip muscle strength measures and hop performance LSIs. Hip ER-MVIC (involved: 60.26 [12.01], uninvolved: 63.68 [13.17]N·m/kg) and ER eccentric PKTQ at 60°/s (involved: 32.59 [9.28]; uninvolved: 35.73 [10.50]N·m/kg) were significantly different between limbs (P ≤ .018). Single-hop LSI correlated with hip ER-PKTQ at 180°/s (r = .354) and 300°/s (r = .324, P ≤ .041), while triple-hop LSI correlated with hip ER-MVIC (r = .320), concentric ER-PKTQ at 180°/s (r = .355), eccentric ER-PKTQ at 60°/s (r = .314), and hip ABD-PKTQ at 60°/s (r = .364) and 300°/s (r = .336, P ≤ .049). Men athletes demonstrated symmetrical hop performance and hip muscle strengths, except for ER hip's MVIC and isokinetic eccentric peak torque at 60°/s 2years after ACLR. Hop performance LSIs had a few, yet positive moderate relationships with involved hip ABDs and ER strength measures. This may indicate that hip ABD and ER muscle strength measures contribute to athletes' hop performances 2years after ACLR. Post-ACLR rehabilitation programs might incorporate hip muscle strengthening training to improve athletes' functional performances.

Hip Fracture In A Healthy Collegiate Distance Runner Without Relevant Hip Symptoms

HX: A 20-year-old female Division I collegiate distance runner sustained a traumatic right femoral neck fx due to slipping while competing in the conference cross-country championships in February of 2021. She presented to AT and PT in the Spring of 2020 with bilateral, lateral knee pain consistent with ITBS. She had a history of metatarsal stress fx the previous season. The athlete had a normal DEXA scan, normal blood work, and self-reported no history of amenorrhea. PE: Pre-fracture, the athlete had full hip and knee AROM and PROM without pain. The athlete was able to run 40-50 miles per week without exacerbation of ITBS, including 10-12 mile long runs without symptoms. Athlete underwent uncomplicated ORIF following injury to stabilize the fracture. Bony healing was delayed until 7 months post-op. An athlete was making progress with rehab as expected through the end of the school year (3 months post-op) before returning home for summer. Upon returning to campus from summer vacation, the athlete had a plateau in her rehab process. She began to exhibit leg length discrepancy, pelvic position abnormalities, grossly limited AROM/PROM of hip extension and ER, significantly decreased strength of the R LE, and limited capsular mobility of the hip. DDX:Pre-injury-ITBS/TFL Strain-Vastus Lateralis Muscle Strain-FAIPost Injury-FAI-Scar tissue formation in posterior hip-CRPS-Lumbopelvic Dysfunction TESTS & RESULTS:-Multiple plain radiographs showing delayed healing until 7 months post-op-MSK US showing scar tissue formation at the greater trochanter near gluteus medius insertion and near the superior gluteal nerve-Bloodwork pending WORKING DIAGNOSIS: -Pathological Femoral Neck Fx w/delayed healing s/p ORIF w/ associated FAI secondary to lumbopelvic dysfunction TREATMENT AND OUTCOMES:The athlete performing dual and single limb lower extremity strengthening exercises including closed-kinetic chain w/resistance. She went through a return to walking/jogging protocol and was able to jog on the track for 400 m before the plateau in progress. She is currently performing dual-leg bodyweight bridges and basic leg lifts. The athlete is unable to perform single-leg bridges on right. AT and PT performing graded joint mobilizations to promote extension and external rotation.

Association between Selected Screening Tests and Knee Alignment in Single-Leg Tasks among Young Football Players.

This study aimed to examine the relationship between knee valgus in the frontal plane projection angle (FPPA) during single-leg squat (SLS), single-leg landing (SLL), and other selected clinical tests in young athletes. Forty-three young healthy elite football players (age: 13.2 (1.7) years) that were regularly training in a local sports club participated in the study. The FPPA was assessed using 2D video analysis. The screening tests included the passive single-leg raise (PSLR), hip external and internal rotation (hip ER and IR), sit and reach test, weight-bearing lunge test (WBLT), modified star excursion balance test (mSEBT), countermovement jump (CMJ), single-leg hop for distance (SLHD), and age peak height velocity (APHV). There was a significant positive relationship between the knee valgus angles in the SLS test and the sit and reach test (r = 0.34) and a negative relationship with the hip ER ROM (r = −0.34) (p < 0.05). The knee valgus angles in the SLL were negatively associated with the hip IR (r = −0.32) and ER ROM (r = −0.34) and positive associated with the WBLT (r = 0.35) and sit and reach test (r = 0.33) (p < 0.05). Linear regression analysis showed that the results of the hip ER ROM and sit and reach tests were independent predictors of the FPPA in the SLS test (r2 = 0.11, p = 0.03 and r2 = 0.12, p = 0.02, respectively). The conducted study showed that individuals with more hip range of motion, more spine flexion extensibility, and less ankle dorsiflexion ROM may be more likely to experience high degrees of knee valgus in FPPA.

Morphological Changes of the Hip Commonly Associated With Femoroacetabular Impingement Are Not Correlated With Rotational Range of Hip Motion in Elite Soccer Athletes.

Morphological changes characteristic of femoroacetabular impingement (FAI) are common in soccer players. However, the clinical relevance of such anatomical variations is still not well-defined. We hypothesized that high alpha angle values and/or acetabular retroversion index (ARI) are correlated with rotational range of motion (ROM) of the hip and that there are clinical-radiological diferences between the dominant lower limb (DLL) and nondominant lower limb (NDLL) in professional soccer players. Cross-sectional. Level 3. A total of 59 male professional soccer players (average age 25.5 years, range 18-38 years) were evaluated in the preseason. As main outcome measures, we evaluated the alpha angle and the ARI and hip IR and ER ROM with radiographic analysis. The measurements taken on DLL and NDLL were compared and a significant difference was found between the sides in the ER (P = 0.027), where the DLL measures were 1.54° (95% CI, 0.18-2.89) greater than the NDLL. There were no significant differences between the sides in the measures of IR (P > 0.99), total ROM (P = 0.07), alpha angle (P = 0.250), and ARI (P = 0.079). The correlations between the rotation measurements and the alpha angle in each limb were evaluated and the coefficient values showed no correlation; so also between the ARI and rotation measures. Morphological changes of the femur or acetabulum are not correlated with hip IR and ER ROM in male professional soccer players. ER on the dominant side was greater than on the nondominant side. There was no significant difference in the other measurements between sides. In clinical practice, it is common to attribute loss of hip rotational movement to the presence of FAI. This study shows that anatomical FAI may not have a very strong influence on available hip rotational movement in professional soccer athletes.

Upper Extremity and Hip Range of Motion Changes Throughout a Season in Professional Baseball Players

Background: Loss of upper and lower extremity range of motion (ROM) is a significant risk factor for injuries in professional baseball players. Purpose/Hypothesis: The purpose was to determine changes in ROM in professional baseball players over the course of a single season and their careers. We hypothesized that pitchers and position players would lose ROM, specifically total shoulder motion (total ROM [TROM]) and hip internal rotation (IR), over the course of a season and their careers. Study Design: Case series; Level of evidence, 4. Methods: Upper and lower extremity ROM measurements were recorded during pre-, mid-, and postseason on all professional baseball players for a single organization between 2011 and 2018. ROM measurements were compared for pitchers and position players over the course of the season and their careers. Also, ROM measurements over the pre-, mid-, and postseason were compared between pitchers and position players. Results: A total of 166 professional baseball players (98 pitchers, 68 position players) were included. Pitcher hip external rotation (ER; P < .001), IR (P = .010), and TROM (P < .001) for lead and trail legs decreased over the course of the season. Pitcher shoulder ER (P = .005), TROM (P = .042), and horizontal adduction (P < .001) significantly increased over the course of the season. Position player shoulder flexion (P = .046), hip ER (P < .001, lead leg; P < .001, trail leg), and hip TROM (P = .001; P = .002) decreased over the course of the season. Position player shoulder ER (P = .031) and humeral adduction (P < .001) significantly increased over the course of the season. Over the course of pitchers’ careers, there was decreased shoulder IR (P = .014), increased shoulder horizontal adduction (P < .001), and hip IR (P = .042) and hip TROM (P = .027) for the lead leg. Position players experienced loss of hip TROM (P = .010, lead leg; P = .018, trail leg) over the course of their careers. Pitchers started with and maintained more shoulder ER and gained more shoulder TROM over a season as compared with position players. Conclusion: Pitchers and position players saw overall decreases in hip ROM but increases in shoulder ROM over the course of the season and career.

THE IMMEDIATE EFFECTS OF A TOTAL MOTION RELEASE® WARM-UP ON ACTIVE ROTATIONAL HIP RANGE OF MOTION IN OVERHEAD ATHLETES

Reductions in hip range of motion (ROM) correlate with lower extremity injury and alterations in shoulder mechanics in overhead athletes. Such shifts in kinetic-chain dynamics may lead to additional stresses at common injury sites of the upper and lower extremities. Researchers have suggested that Total Motion Release® (TMR®) increases shoulder ROM more effectively than traditional warm-up methods. It is plausible that similar methods may produce increases in ROM at the hip. To explore the effects of a TMR® based intervention on active hip rotational ROM in overhead athletes compared to a traditional athletic warm-up. Randomized Control Trial. Twenty-two secondary school, NCAA Division I, III, and Club student-athlete participants (sex: 13 females, 9 males; sport: 9 javelin, 7 volleyball, 7 baseball; age = 19.3 ± 1.1 years; height = 178 ± 11.4 cm; weight = 76.4 ± 11.2 kg.) were randomly assigned to TMR® (TMRG; n = 11) and traditional warm-up (TWG; n = 11) groups. The TMRG performed three sets of forward flexed trunk twist and seated straight leg raise held for 20 seconds each to the side of ease with a 30-second rest interval. Active hip internal and external rotation was measured using the Clinometer smartphone application immediately before and after intervention. The TMRG experienced significant immediate increases in active dominant hip ER,, active nondominant hip ER, active dominant total hip rotational ROM, and active nondominant total hip rotational ROM (mean change = +6.27°, + 12.2°, + 4.8, and +11.9°), compared to the TWG (mean change = +0°, + 1.9°, -1°, and 1°) respectively. Using TMR® motions and principles as a warm-up produced meaningful changes in active hip rotational ROM bilaterally in overhead athletes. IIb.

Effects of Game Performance on Softball Pitchers and Catchers.

Oliver, GD, Plummer, HA, Washington, JK, Weimar, WH, and Brambeck, A. Effects of game performance on softball pitchers and catchers. J Strength Cond Res 33(2): 466-473, 2019-The purpose of this study was to examine the effects of game exposure on pitchers and catchers' hip and glenohumeral range of motion (ROM), isometric strength, and vertical jump performance and power. Five college female softball pitchers (174.24 ± 7.53 cm; 82.10 ± 11.27 kg; 20 ± 1.82 years) and 4 catchers (165.10 ± 9.04 kg; 68.61 ± 3.87 cm; 20 ± 1.41 years) participated. Hip and glenohumeral rotational ROM; hip and glenohumeral rotational isometric strength; hip abduction and adduction strength; and vertical jump height were assessed pre- and postgame exposure. The catchers displayed significantly greater throwing side hip internal rotation (IR) ROM (mean difference = +6.88°, p = 0.03) postgame exposure, whereas the pitchers exhibited less IR (mean difference = -2.02%, p = 0.013) and external rotation (ER; mean difference = -1.95%, p = 0.026) strength in the nonthrowing side hip pre vs. postgame exposure. The performance demands of pitchers and catchers vary greatly, causing position-specific decreases/increases in various tests following game performance. Pitchers exhibited significant decreases in nonthrowing side hip IR and ER strength. In catchers, throwing side hip IR ROM significantly increased following game exposure. Further evaluation of ROM, strength, and power is necessary as it is unknown how these changes following a game affect sports performance or risk of injury.

Predicting individual risk for medial tibial stress syndrome in navy recruits

ObjectivesQuantifying individual risk for medial tibial stress syndrome (MTSS) is valuable due to the high prevalence, substantial financial and service costs, and lengthy recovery time of the condition. Identification of those at risk is a key first step in prevention of the condition. This study aimed to test a suite of best evidence risk factors in a cohort of Navy recruits and to develop a predictive model for individuals at risk of MTSS. DesignProspective cohort study of Navy recruits undergoing initial training MethodsA prospective cohort design, this study screened recruits by assessing gender, MTSS history, years of running experience, orthotic use, BMI, navicular drop, ankle plantarflexion and hip external rotation at the beginning of basic training. Follow-up was conducted at completion of training (11 weeks). ResultsVolunteers included 123 recruits (28 females and 95 males). Thirty developed MTSS (19 males and 11 females). Stepwise logistic regression of one half of the data produced a significant model (p<0.001), comprising female gender (OR 4.4, 95% CI 1.0, 18.9, p=0.05), MTSS history (OR 18.3, 95% CI 3.6, 91.5, p<0.01) and increased hip ER (OR 1.1 per degree, 95% CI 1.0, 1.202, p=0.05). Findings validated with the other half of the cohort and receiver operating characteristic curve analysis showed the model had 82% sensitivity and 84% specificity. ConclusionsThis predictive model provides military institutions, clinicians and instructors with a strong and accurate calculator for predicting an individual recruit’s risk of MTSS.

Characteristic of shoulder and hip rotation range of motion in adolescent tennis players.

Adolescent tennis players require sufficient hip and shoulder flexibility to achieve the kinetic chain of a tennis stroke or serve. Hence, the objective of this study is to measure the glenohumeral joint internal and external rotation (IR and ER, respectively) and hip ER range of motion (ROM) and to compare these parameters between experienced and beginner-level adolescent tennis players. Twenty-three adolescent tennis players were divided into experienced (N.=12) and beginner groups (N.=11) on the basis of the adolescent national ranking of the Taiwan Tennis Association. For all participants, the shoulder IR and ER at 90° of abduction were measured, and hip ER which used Partick's Test was also evaluated on the dominant and nondominant sides. The total rotation ROM of the shoulder and the difference in shoulder ER, IR, and total rotation and hip ER between the dominant and nondominant sides were also calculated after measurements. An independent-samples t-test was applied to test the homogeneity of the participants' demographic data and the difference in shoulder IR, ER, and total rotation and hip ER values between the dominant and nondominant sides. Subsequently, a repeated-measured two-way analysis of variance (2 × 2) was used to compare the dominant and nondominant shoulder and hip ROM of the participants between the experienced and beginner groups. The experienced group exhibited a significantly less total rotation ROM than the beginner group. In addition, both groups showed less dominant shoulder IR ROM and more dominant shoulder ER ROM compared with the nondominant side. Compared with the experienced group, the beginner group showed an obvious difference in total shoulder rotation between dominant and nondominant sides. More tightness for the hip ER was observed in the experienced group than in the beginner group, but no difference was observed between the dominant and nondominant sides in both groups. Beginner adolescent tennis players differ more in the degree of total shoulder ROM between the dominant and nondominant sides than experienced players. Beginner and experienced adolescent tennis players also have more shoulder ER and less IR on the dominant side. The results suggest that beginner-level adolescent tennis players should undergo a stretching and strengthening program to reduce the potential risk of injury and possibly enhance performance.

Differentials in Turnout Among Professional Classical Ballet Dancers

Screening and training of professional dancers is commonly based around beliefs that a large range of turnout is more advantageous in the ballet industry. This belief leads dancers who have limited hip external rotation to compensate by forcing turnout at the knee and ankle, which has been linked to injury. To examine if there is a difference in degree of turnout between three levels of dancers (corps, soloist, principal) in a professional classical ballet company. An additional aim was to establish average values for the range of turnout and hip rotation present in the dancers. Forty-five professional dancers from The Australian Ballet (25 female, 20 male) participated in the study. Active and passive hip external rotation (hip ER) was measured in supine using inclinometers, and functional turnout in ballet first position (lower limb external rotation, LLER) was measured using foot traces utilising bony landmarks. Below-hip external rotation (BHER) was also calculated. No relationship was found among level of dancer and passive hip ER, active hip ER, LLER, and BHER. Professional dancers had on average 50.2° of passive hip ER range, 35.2° of active hip ER, and 133.6° of functional turnout position. In addition, no correlation was found between LLER and hip ER, but significant correlations were found between LLER and BHER. Hip rotation range of motion is similar across all levels of professional dancers. Average values for passive and active hip ER and functional turnout were established.

Greater understanding of normal hip physical function may guide clinicians in providing targeted rehabilitation programmes

This study investigated tests of hip muscle strength and functional performance. The specific objectives were to: (i) establish intra- and inter-rater reliability; (ii) compare differences between dominant and non-dominant limbs; (iii) compare agonist and antagonist muscle strength ratios; (iv) compare differences between genders; and (v) examine relationships between hip muscle strength, baseline measures and functional performance. Reliability study and cross-sectional analysis of hip strength and functional performance. In healthy adults aged 18-50years, normalised hip muscle peak torque and functional performance were evaluated to: (i) establish intra-rater and inter-rater reliability; (ii) analyse differences between limbs, between antagonistic muscle groups and genders; and (iii) associations between strength and functional performance. Excellent reliability (intra-rater ICC=0.77-0.96; inter-rater ICC=0.82-0.95) was observed. No difference existed between dominant and non-dominant limbs. Differences in strength existed between antagonistic pairs of muscles: hip abduction was greater than adduction (p<0.001) and hip ER was greater than IR (p<0.001). Men had greater ER strength (p=0.006) and hop for distance (p<0.001) than women. Strong associations were observed between measures of hip muscle strength (except hip flexion) and age, height, and functional performance. Deficits in hip muscle strength or functional performance may influence hip pain. In order to provide targeted rehabilitation programmes to address patient-specific impairments, and determine when individuals are ready to return to physical activity, clinicians are increasingly utilising tests of hip strength and functional performance. This study provides a battery of reliable, clinically applicable tests which can be used for these purposes.

Physical and Physiological Profile of Elite Female Soccer Players

0262 PURPOSE: To develop a physical and physiological profile of elite female soccer players. METHODS: Data was collected from 26 female soccer players during the first two weeks of pre-season training camp for a Women's United Soccer Association team. Measurements were taken of body composition, aerobic capacity, speed, functional strength, posture, ROM of the hip and knee, LE flexibility, and core control using Sahrmann's lower abdominal progression. Dynamic functional alignment was measured during an 8» step down, single leg squat, and landing from a jump off a 12» platform using a system developed by the authors. RESULTS: Mean body fat % was 17 % (±5). Mean VO2 max was 46 ml/kg/min (±5.4ml/kg/min), and ventilatory threshold occurred at 87% (± 3.7) of VO2max. Times for the 40yd dash, 10 yd start andflying 30 yds were 5.87 (±0.27), 2.00 (±0.1) and 3.85 (± 0.19) secs respectively. Mean vertical jump height was 16». Mean hamstring flexibility was 77°(±6.1°) and 73° (±7.3) for dominant and non-dominant legs respectively. All subjects presented with a positive Thomas test and femoral anteversion as measured by Craig's test. The average knee flexion in the resting position was 50°(±11°). Mean Hip IR and ER were 33°(± 8°) and 25°(±6.7°) respectively. In static standing posture, 15 subjects had bilateral and 10 subjects had unilateral femoral IR, 8 of which were dominant limbs. Eight-one percent of the subjects scored 2 (maximum score 5) during testing of core control. Ninety-six percent of subjects demonstrated deviations from neutral alignment during the step down and single leg squat, while 60% demonstrated a stiff knee landing and/or takeoff. CONCLUSION: As compared to established normative data, the players demonstrated limitations in hip IR and ER, hamstring and 2 joint hip flexor muscle length. The majority of players demonstrated inadequate core control and deviations in dynamic alignment.