Clinical evaluation of hip joint rotation range of motion in adults

Hip Active Range of Motion in Patients with Femoroacetabular Impingement Syndrome

Femoroacetabular impingement syndrome (FAIS) is characterized by hip pain and restricted range of motion (ROM), typically due to structural conflict between the femoral neck and the acetabulum. This study aimed to quantify active ROM limitations in FAIS patients, comparing them with healthy controls to establish normative values, particularly in non-conflicting directions. Methods: A total of 53 FAIS patients scheduled for hip arthroscopy were compared to 49 healthy matched controls. Active ROM was assessed using inertial measurement unit (IMU) sensors, with measurements taken in standing and prone positions. Outcomes included flexion, external rotation, internal rotation, and total rotation ROM, alongside demographic and radiographic data. Gender-based ROM differences were also analyzed. Results: FAIS patients demonstrated significant reductions in flexion, internal rotation, and total rotation ROM in the involved hip, with large effect sizes, while external rotation remained unaffected. ROM in the uninvolved hip was also lower than in controls but showed increased external rotation. Gender differences were observed, with females exhibiting significantly higher internal rotation and, in healthy controls, greater total rotation than males. Conclusions: FAIS patients have significant active ROM restrictions in non-conflicting directions, suggesting broader joint limitations potentially tied to early hip osteoarthritis or capsular and musculoskeletal adaptations. Gender differences highlight the importance of individualized ROM assessment. This study introduces IMU-based ROM evaluation as a promising tool for diagnosing and monitoring FAIS, providing insights into functional impairments that can be used to guide targeted interventions.

Role of Hip Internal Rotation Range and Foot Progression Angle for Preventing Jones Fracture During Crossover Cutting

Jones fracture is a common injury in soccer players, caused by overload on the fifth metatarsal (M5) that can occur during crossover cutting. This study aimed to investigate the effects of the hip internal rotation (HIR) range in passive and dynamic conditions and foot progression angle (FPA) on the forces applied to the M5 during crossover cutting. The study included 20 men with experience playing soccer. The passive HIR was measured in the prone position. A 3-dimensional motion analysis system, force plates, and Footscan were used to measure the angle of the lower limb, including dynamic HIR, FPA, and plantar pressure to the M5, during crossover cutting in the 45° direction. Pearson correlation coefficient was measured to examine the relationship between variables. Passive and dynamic HIR were not related to the plantar pressure on the M5 (P > .05). However, increased FPA in movement direction correlated with a reduction in plantar pressure on the M5 (r = -.56, P < .01). Minimizing the FPA with respect to the new direction during crossover cutting reduced plantar pressure on the M5 and thus could prevent Jones fracture.

Comparing the Hip and Lumbar Joint Range of Motion in Patients With Lower Lumbar Disc Herniation and Healthy Subjects

BACKGROUND

One possible factor contributing to low back pain is hip range of motion (ROM). However, there is inconstancy in published studies, which may be due to the heterogeneity of patients. Therefore, the present study focuses on the relationship between hip ROM and lower lumbar disc herniation (LLDH).

METHOD

A cross-sectional study involved 52 participants between 18 and 65 years old. Two digital inclinometers were utilized to measure the ROM of the lumbar and hip joints in all study participants. For each outcome, 2 measurements were conducted, and the mean of the 2 measurements was utilized for analysis. The level of statistical significance was established at P ≤ .05.

RESULTS

The difference in all ROM between the 2 groups is significant except for dominant hip flexion (P < .05). Lumbar flexion was reduced in LLDH compared with healthy individuals (P = .003). The findings manifested a significant correlation between right lumbar rotation and nondominant hip abduction (P = .05, R = .388) and between left lumbar lateral bending and nondominant hip flexion (P = .008, R = .510).

CONCLUSION

Patients with LLDH have reduced hip ROM and lumbar flexion compared with healthy individuals. The study showed correlations between hip and lumbar ROM and emphasized the significance of evaluating hip ROM in LLDH for assessment and treatment planning.

Reliability and validity of computer vision-based markerless human pose estimation for measuring hip and knee range of motion

Telerehabilitation requires accurate joint range of motion (ROM) measurement methods. The aim of this study was to evaluate the reliability and validity of a computer vision (CV)-based markerless human pose estimation (HPE) application measuring active hip and knee ROMs. For this study, the joint ROM of 30 healthy young adults (10 females, 20 males) aged 20-33 years (mean: 22.9 years) was measured, and test-retests were assessed for reliability. For validity evaluation, the CV-based markerless HPE application used in this study was compared with an identical reference picture frame. The intraclass correlation coefficient (ICC) for the CV-based markerless HPE application was 0.93 for active hip inner rotation, 0.83 for outer rotation, 0.82 for flexion, 0.82 for extension, and 0.74 for knee flexion. Correlations (r) of the two measurement methods were 0.99 for hip-active inner rotation, 0.98 for outer rotation, 0.87 for flexion, 0.85 for extension, and 0.90 for knee flexion. This study highlights the potential of a CV-based markerless HPE application as a reliable and valid tool for measuring hip and knee joint ROM. It could offer an accessible solution for telerehabilitation, enabling ROM monitoring.

Generative adversarial networks to create synthetic motion capture datasets including subject and gait characteristics

Resource-intensive motion capture (mocap) systems challenge predictive deep learning applications, requiring large and diverse datasets. We tackled this by modifying generative adversarial networks (GANs) into conditional GANs (cGANs) that can generate diverse mocap data, including 15 marker trajectories, lower limb joint angles, and 3D ground reaction forces (GRFs), based on specified subject and gait characteristics. The cGAN comprised 1) an encoder compressing mocap data to a latent vector, 2) a decoder reconstructing the mocap data from the latent vector with specific conditions and 3) a discriminator distinguishing random vectors with conditions from encoded latent vectors with conditions. Single-conditional models were trained separately for age, sex, leg length, mass, and walking speed, while an additional model (Multi-cGAN) combined all conditions simultaneously to generate synthetic data. All models closely replicated the training dataset (<8.1 % of the gait cycle different between experimental and synthetic kinematics and GRFs), while a subset with narrow condition ranges was best replicated by the Multi-cGAN, producing similar kinematics (<1°) and GRFs (<0.02 body-weight) averaged by walking speeds. Multi-cGAN also generated synthetic datasets and results for three previous studies using reported mean and standard deviation of subject and gait characteristics. Additionally, unseen test data was best predicted by the walking speed-conditional, showcasing synthetic data diversity. The same model also matched the dynamical consistency of the experimental data (32 % average difference throughout the gait cycle), meaning that transforming the gait cycle data to the original time domain yielded accurate derivative calculations. Importantly, synthetic data poses no privacy concerns, potentially facilitating data sharing.

Effect of pelvic floor fascial mobilization on pelvic floor dysfunction in multiparous pregnant women - A randomized pilot study

BACKGROUND

Pelvic floor fascial mobilization (PFFM) is an innovative intravaginal and/or intrarectal manual therapy technique developed to treat pelvic distress by improving fascial gliding and muscle function.

AIM

The effect of PFFM on pelvic floor distress during pregnancy was compared to conventional pelvic floor muscle training.

METHODS

A pilot prospective randomized clinical trial. The primary outcome was the strength and function of the pelvic floor muscles measured via the Oxford grading scale, perineometry, and hip range of motion. Each subject was treated twice, one week apart.

RESULTS

Forty multiparous pregnant women at 24-30 weeks gestation, with pelvic distress, were allocated to PFFM (study group (n = 20)) vs. pelvic floor muscle training (control group (n = 20)). There was no difference in the severity of pelvic distress between the study and control groups before the interventions (PFDI-20: 27.1 ± 12.2 vs. 26.0 ± 13.5, respectively, p = 0.7). Twenty-six subjects completed the study protocol. PFDI-20 showed significant improvement: 42% improvement in the study group vs. 12% improvement in the controls (p = 0.001 for both groups). Group-by-time interaction (Cohen's d) was significant after the first treatment session for Oxford score, right hip internal rotation range of motion, and cervical length in the PFFM group and for perineometry and right hip internal rotation at the end of the study.

CONCLUSIONS

Based on this pilot randomized trial, PFFM may potentially and partially 1. Alleviate symptoms, 2. Improve pelvic floor function and strength, and 3. Elongate the cervix after one or two treatment sessions. Further, a more extensive study is needed to confirm these results.

Establishing a Reference Database for Select Clinical Measures in National Basketball Association Players

BACKGROUND

Musculoskeletal injuries are prevalent in the NBA and are associated with a significant number of games missed. There is a lack of reference data for clinical measures in NBA players, making it difficult for sports medicine professionals to set goals and develop programs.

HYPOTHESIS

Values for clinical measures in NBA players will differ from those of the general population but will not differ between dominant (D) and nondominant (ND) limbs.

STUDY DESIGN

Descriptive laboratory study.

LEVEL OF EVIDENCE

Level 3.

METHODS

Clinical measures were taken on 325 players invited to NBA training camp (2008-2022). Measures included range of motion for great toe extension, hip rotation, weightbearing ankle dorsiflexion, flexibility, arch height (AH) indices, and tibial varum.

RESULTS

Clinical values for NBA players differ from reference norms of the general population. Results for NBA players include great toe extension (D, 40.4°; ND, 39.3°), 90/90 hamstring (D, 41.5°; ND, 40.9°), hip internal rotation (D, 29.0°; ND, 28.8°), hip external rotation (D, 29.7°; ND, 30.9°), total hip rotation (D, 60.2°; ND, 60.4°), Ely (D, 109.9°; ND, 108.8°), AH difference (D, 0.5 mm; ND, 0.5 mm), AH index (D, 0.310; ND, 0.307), arch stiffness (D, 0.024; ND, 0.024), arch rigidity (D, 0.924; ND, 0.925), tibial varum (D, 4.6°; ND, 4.5°), and weightbearing ankle dorsiflexion (D, 35.4°; ND, 35.6°). Descriptive statistics are presented; 2-tailed paired t tests show that, whereas most measures demonstrated differences between sides, the results were not statistically significant.

CONCLUSION

Clinical measures of NBA players differ from those reported for the general population and athletes of other sports although there were no statistically significant differences between D and ND limbs.

CLINICAL RELEVANCE

Establishing a reference database may help clinicians develop more sensitive and more effective preseason and return-to-play screening processes, aiding the management of player orthopaedic care and reducing injury risk.

Range of Motion Measurements of the Hip Joint Are Useful in Screening for Acetabular Dysplasia in Healthy Young Japanese Women

The purpose of this study is to clarify whether a hip range of motion (ROM) measurement is useful in screening for early hip osteoarthritis with acetabular dysplasia (AD). Subjects were 58 healthy Japanese women volunteers (21.1 ± 0.7 (20 - 22)). We evaluated a total of 116 hip joints in these 58 cases. Sharp angle and centeredge angle were 44.1° ± 3.1° (37.0° - 51.5°) and 30.7°± 6.2° (19.5° - 47.0°), respectively. AD was present in 47.4%, but there were no severe cases. First, we compared the ROM of the hip joints with AD (AD group) and without AD (control group) according to the Mann-Whitney U test. Extension angles and external rotation angles in the AD group were significantly smaller than in the control group (18.9°± 6.1° VS. 22.1°± 4.2°, p= 0.01636, 26.3°± 8.9° VS. 34.1°± 8.8°, p= 0.001362, respectively). Next, we evaluated the following factors associated with AD by logistic regression analysis after adjustment for age: flexion, extension and internal and external rotation angles of the hip joint. As a result, internal rotation and external rotation were extracted as related factors. The area under the ROC curve was determined to have a moderate accuracy (0.72996). Cut off values of internal rotation and external rotation angles were 50 degrees and 35 degrees, respectively. Our findings suggest that ROM measurement of the internal and external rotation angles would be useful as a screening for AD in healthy young Japanese women without symptoms.

Assessment of Hip and Lumbar Spine Range of Motion After Total Hip Arthroplasty Using a Single Camera Markerless System

BACKGROUND

Total hip arthroplasty (THA) is one of the most cost-effective and successful procedures in orthopedics. However, assessing the post-operative range of motion (ROM) remains a challenge due to the limitations of traditional measurement methods. This study aimed to evaluate hip and spine ROM post-operatively and single-leg balance, using a single-camera markerless motion capture system, and compare outcomes with pre-operative ROM and with an age-matched healthy control group.

METHODS

An interventional study was conducted from January 2018 to December 2021. Twenty patients with hip osteoarthritis underwent THA and were assessed using a single-camera markerless system (Kinetisense software). Measurements were taken one month pre-operatively and one year post-operatively.

RESULTS

Significant improvements were observed in hip and lumbar spine ROM variables after THA. The most notable enhancements were in hip and spinal flexion. Compared to the control group, the THA group showed minor deficits in hip ROM, particularly in external rotation. Single-leg balance demonstrated improved stability post-operatively.

CONCLUSIONS

The single-camera markerless motion capture system offers a promising alternative for assessing hip and lumbar spine ROM, presenting potential advantages over manual goniometry and traditional 3D motion capture systems. Using this system for the evaluation of patients after THA, it seems that THA significantly enhances hip and lumbar spine ROM. Future research should focus on validating the accuracy of markerless systems.

Effects of hip joint kinematics on the effective pelvis stiffness and hip impact force during simulated sideways falls

Improved understanding is required on how hip fracture risk is influenced by landing configuration. We examined how hip impact dynamics was affected by hip joint kinematics during simulated sideways falls. Twelve young adults (7 males, 5 females) of mean age 23.5 (SD = 1.5) years, participated in pelvis release experiments. Trials were acquired with the hip flexed 15° and 30° for each of three hip rotations: +15° ("external rotation"), 0°, and -15° ("internal rotation"). During falls, force-deformation data of the pelvis were recorded. Outcome variables included the peak hip impact force (Fexperimental) and effective stiffness of the pelvis (k1st, ksecant, and kms) determined with different methods suggested in literature, and predicted hip impact force during a fall from standing height (F1st, Fsecant and Fms). The two-way repeated-measures ANOVA was used to test whether these variables were associated with hip joint angles. The Fexperimental, ksecant and Fsecant were associated with hip rotation (F = 5.587, p = 0.005; F = 9.278, p < 0.0005; F = 5.778, p = 0.004, respectively), and 15 %, 31 % and 17 % smaller in 15° external than internal rotation (848 versus 998 N; 24.6 versus 35.6 kN/m; 2,637 versus 3,170 N, respectively). However, none of the outcome variables were associated with hip flexion (p > 0.05). Furthermore, there were no interactions between the hip rotation and flexion for all outcome variables (p > 0.05). Our results provide insights on hip impact dynamics, which may help improve a hip model to assess hip fracture risk during a fall.

Advancement in total hip implant: a comprehensive review of mechanics and performance parameters across diverse novelties

The UK's National Joint Registry (NJR) and the American Joint Replacement Registry (AJRR) of 2022 revealed that total hip replacement (THR) is the most common orthopaedic joint procedure. The NJR also noted that 10-20% of hip implants require revision within 1 to 10 years. Most of these revisions are a result of aseptic loosening, dislocation, implant wear, implant fracture, and joint incompatibility, which are all caused by implant geometry disparity. The primary purpose of this review article is to analyze and evaluate the mechanics and performance factors of advancement in hip implants with novel geometries. The existing hip implants can be categorized based on two parts: the hip stem and the joint of the implant. Insufficient stress distribution from implants to the femur can cause stress shielding, bone loss, excessive micromotion, and ultimately, implant aseptic loosening due to inflammation. Researchers are designing hip implants with a porous lattice and functionally graded material (FGM) stems, femur resurfacing, short-stem, and collared stems, all aimed at achieving uniform stress distribution and promoting adequate bone remodeling. Designing hip implants with a porous lattice FGM structure requires maintaining stiffness, strength, isotropy, and bone development potential. Mechanical stability is still an issue with hip implants, femur resurfacing, collared stems, and short stems. Hip implants are being developed with a variety of joint geometries to decrease wear, improve an angular range of motion, and strengthen mechanical stability at the joint interface. Dual mobility and reverse femoral head-liner hip implants reduce the hip joint's dislocation limits. In addition, researchers reveal that femoral headliner joints with unidirectional motion have a lower wear rate than traditional ball-and-socket joints. Based on research findings and gaps, a hypothesis is formulated by the authors proposing a hip implant with a collared stem and porous lattice FGM structure to address stress shielding and micromotion issues. A hypothesis is also formulated by the authors suggesting that the utilization of a spiral or gear-shaped thread with a matched contact point at the tapered joint of a hip implant could be a viable option for reducing wear and enhancing stability. The literature analysis underscores substantial research opportunities in developing a hip implant joint that addresses both dislocation and increased wear rates. Finally, this review explores potential solutions to existing obstacles in developing a better hip implant system.

Do hip resurfacing and short hip stem arthroplasties differ from conventional hip stem replacement regarding impingement-free range of motion?

Total hip joint replacement (THR) is clinically well-established. In this context, the resulting range of motion (ROM) is crucial for patient satisfaction when performing joint movements. However, the ROM for THR with different bone preserving strategies (short hip stem and hip resurfacing) raises the question of whether the ROM is comparable with conventional hip stems. Therefore, this computer-based study aimed to investigate the ROM and type of impingement for different implant systems. An established framework with computer-aided design 3D models based on magnetic resonance imaging data of 19 patients with hip osteoarthritis was used to analyse the ROM for three different implant systems (conventional hip stem vs. short hip stem vs. hip resurfacing) during typical joint movements. Our results revealed that all three designs led to mean maximum flexion higher than 110°. However, hip resurfacing showed less ROM (-5% against conventional and -6% against short hip stem). No significant differences were observed between the conventional and short hip stem during maximum flexion and internal rotation. Contrarily, a significant difference was detected between the conventional hip stem and hip resurfacing during internal rotation (p = 0.003). The ROM of the hip resurfacing was lower than the conventional and short hip stem during all three movements. Furthermore, hip resurfacing shifted the impingement type to implant-to-bone impingement compared with the other implant designs. The calculated ROMs of the implant systems achieved physiological levels during maximum flexion and internal rotation. However, bone impingement was more likely during internal rotation with increasing bone preservation. Despite the larger head diameter of hip resurfacing, the ROM examined was substantially lower than that of conventional and short hip stem.

Validity and Reliability of Inertial Measurement Units in Active Range of Motion Assessment in the Hip Joint

Measuring joint range of motion has traditionally occurred with a universal goniometer, inclinometer, or expensive laboratory systems. The popularity of the inertial measurement unit (IMU) is growing, enabling the small and even single portable device to measure the range of motion. Until now, they were not used to assess hip joint range of motion. Our study aimed to check the validity of IMUs in assessing hip range of motion and compare them to other measurement devices-universal goniometer and inclinometer. Twenty participants completed three hip movements (flexion in standing and prone internal and external rotation) on both hips. Two testers independently assessed each movement with a goniometer, digital inclinometer, and IMU at different time points. To assess the agreement of active hip ROM between devices, Intraclass Correlation Coefficient (ICC) and Bland-Altman analysis were used. Furthermore, inter-rater and intra-rater reliability were also assessed by using ICC and Bland-Altman analysis. Limits of agreement (LOA) were calculated using Bland-Altman plots. The IMU demonstrated good to excellent validity (ICC: 0.87-0.99) compared to the goniometer and digital inclinometer, with LOAs < 9°, across all tested movements. Intra-rater reliability was excellent for all devices (ICC: 0.87-0.99) with LOAs < 7°. However, inter-rater reliability was moderate for flexion (ICC: 0.58-0.59, LOAs < 22.4) and poor for rotations (ICC: -0.33-0.04, LOAs < 7.8°). The present study shows that a single inertial measurement unit (RSQ Motion, RSQ Technologies, Poznan, Poland) could be successfully used to assess the active hip range of motion in healthy subjects, comparable to other methods accuracy.

Predicting the Clean Movement Technique in Crossfit® Athletes Using an Optimal Upper-Limb Range of Motion: A Prospective Cohort Study

BACKGROUND

The aim of this study was to determine the optimal upper-limb range of motion (ROM) profile for the catch phase of the clean movement (CPCM) and to identify the key ROMs for performing the CPCM in CrossFit® athletes.

METHODS

A prospective cohort study of twenty CrossFit® athletes aged 20-36 years was conducted. Data were collected regarding age, anthropometrics, CrossFit® training experience and upper-limb ROM. The ROM was measured using the ROM-SPORT method. After 7 months, athletes performed a clean movement with a load of 80% one repetition maximum. A Bayesian Student's t-analysis, binary logistic regression analysis and Receiver Operating Characteristic analysis were performed.

RESULTS

The optimal upper-limb ROM profile that predicted correct CPCM performance was 78° in shoulder extension, 173° in shoulder flexion, 107° in shoulder external rotation, 89° in shoulder internal rotation, 153° in elbow flexion, 99° in elbow pronation and 92° in wrist extension (area under the curve ≥ 651; positive predictive value ≥ 80%). Shoulder external rotation, elbow pronation and wrist extension were found to be the most important ROMs for the efficient and safe performance of CPCM (area under the curve ≥ 854; positive predictive value ≥ 85.7%).

CONCLUSION

The upper-limb ROM profile is associated with proper clean performance. Further studies are warranted to determine whether improving flexibility on upper-limb ROM may improve proper clean movement performance.

How Much Hip Motion Is Used in Real-Life Activities? Assessment of Hip Flexion by a Wearable Sensor and Implications After Total Hip Arthroplasty

BACKGROUND

Hip range of motion precautions are often considered a requirement for patients after total hip replacement. Few studies have attempted to estimate hip motion during activities of daily living. The purpose of this study is to evaluate hip range of motion and gait during real-life activities in healthy individuals with a novel tracking wearable sensor.

METHODS

Thirty subjects used a hip motion tracking device during a series of tested activities. Healthy volunteers were selected, and subjects were excluded if they reported symptoms in the limb or known deviation in their gait. Hip flexion was evaluated during common activities of daily living.

RESULTS

Hip range of motion during walking averaged minimum to maximum hip flexion of 9.9°-49.3°, respectively. During stair ascent, the average flexion arc widened from minimum 19.6° to maximum 67.8° flexion. Stair descent had the most narrow arc of 26.2°-52.4° hip flexion. Squatting averaged 120.0° of hip flexion, with the transition from sitting to standing averaging 103.0°. Getting on and off of the toilet averaged maximum 112.6°, while tying shoes averaged 126.1° maximum hip flexion.

CONCLUSION

Hip precautions are often enforced after total hip arthroplasty without knowing normal arcs of motion during real-life activities. Knowledge of hip motion during activities of daily living in healthy individuals is useful information in setting goals and in educating total hip arthroplasty patients. This technology can be useful in guiding postoperative precautions and also in monitoring patients after hip replacement with real-time monitoring.

Association between femoroacetabular impingement syndrome and limited lateral hip rotation in young athletes: A case-control study

PURPOSE

Hip pain is very common in athletes. One of the main disorders causing hip pain is femoroacetabular impingement syndrome. This study aimed to identify a new etiological risk factor for femoroacetabular impingement in the hip.

METHODS

This case-control study included 88 young athletes, 34 with pains in the hip (supposedly with femoroacetabular impingement) and 54 controls. Femoroacetabular impingement was diagnosed with a flexion, adduction, internal, and rotation test and a particular type of hip pain during sports activities. The medial (internal) and lateral (external) hip ranges of rotation have been measured with an inclinometer. The data were analyzed using a t-test, the Wilcoxon test, the Mann-Whitney U test, and logistic regression.

RESULTS

There is a statistically significant difference in the external hip rotation range between the athletes with hip pain and controls. Logistic regression analysis showed that external hip range of motion is significantly associated with femoroacetabular impingement.

CONCLUSION

Limited external hip range of motion was found to be significantly associated with the diagnosis of femoroacetabular impingement in young athletes. A biomechanical explanation of the hypothesis that limited external hip rotation can predict femoroacetabular impingement is given. Based on our results, the hip's lateral range of motion screening can be advised within the regular screening of young athletes. Kinesiotherapeutic procedures for stretching the muscles of the medial hip rotors can be advised to prevent the lateral hip rotation restriction and lower the risk of femoroacetabular impingement in case the limited rotation is due to muscular restriction.

LEVEL OF EVIDENCE

level III-case-control study.

Hip Range of Motion Is Increased After Hip Arthroscopy for Femoroacetabular Impingement: A Systematic Review

Purpose

To investigate the impact of arthroscopic correction of symptomatic femoroacetabular impingement on postoperative hip range of motion (ROM), as an objectively measured postoperative clinically reported outcome.

Methods

A systematic review of the current literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, OVID/MEDLINE, EMBASE, and Cochrane databases were queried in November 2020. Studies not reporting pre- to postoperative ROM measurements were excluded. Methodologic quality was assessed using the MINORS assessment, and certainty of evidence was assessed using the GRADE approach. Effect size using standardized mean differences assessed magnitude of change between pre- and postoperative ROM.

Results

In total, 23 studies were included evaluating 2,332 patients. Mean age ranged from 18 to 44.2 years. Flexion, internal rotation (IR), and external rotation (ER) were the predominantly measured ROMs reported in 91%, 100% and 65% of studies, respectively. Observed change following hip arthroscopy was considered significant in 57.1% (flexion), 74% (IR), and 20% (ER). Effect size of change in significantly improved ROMs were weak (16.7% flexion, 33.3% ER), moderate (58.3% flexion, 29.4% IR), and large (25% flexion, 64.7% IR, 66.7% ER). For goniometric assessment mean observed changes ranged as follows: flexion: 0.1° to 12.2°; IR: 3.6° to 21.9°; ER: –2.6° to 12.8°. For computed tomography–simulated assessment, the mean observed change ranged as follows: flexion: 3.0° to 8.0°; IR 9.3° to 14.0°.

Conclusions

Outcome studies demonstrate overall increased range of flexion and IR post-hip arthroscopy, with a moderate and large effect respectively. Change in ER is less impacted following hip arthroscopy. Certainty of evidence to support this observation is low. Current research evaluating changes in this functional ability is limited by a lack of prospective studies and non-standardized measurement evaluation techniques.

Level of Evidence

Level IV, systematic review of Level II-IV studies.

Physical Examination of the Hip: Assessment of Femoroacetabular Impingement, Labral Pathology, and Microinstability

Purpose of Review

Determining the correct diagnosis can be challenging in patients presenting with hip pain. The physical examination is an essential tool that can aid in diagnosis of hip pathology. The purpose of this review is to provide an updated summary of recent literature on the physical exam of the hip, particularly as it relates to diagnosis of femoroacetabular impingement (FAI) syndrome, labral injury, and hip microinstability.

Recent Findings

Physical exam findings consistent with the diagnosis of FAI include reduced supine hip internal rotation and positive flexion-adduction-internal rotation maneuvers. Labral tears can be detected on exam with the Scour test. Studies demonstrate altered hip biomechanics in patients with FAI during activities such as walking and squatting. Those with FAI have slower squat velocities, slower sit-to-stand tests, and increased hip flexion moments during ambulation. Hip microinstability is a dynamic process, which can occur after prior hip arthroscopy. For hip microinstability, the combination of the three following positive tests (anterior apprehension, abduction-extension-external rotation, and prone external rotation) is associated with a 95% likelihood of microinstability as confirmed by examination under anesthesia at the time of surgery.

Summary

A comprehensive hip physical exam involves evaluation of the hip in multiple positions and assessing hip range of motion, strength, as well as performing provocative testing. A combination of physical exam maneuvers is necessary to accurately diagnose FAI syndrome and labral pathology as individual tests vary in their sensitivity and specificity. While an elevated level of suspicion is needed to diagnose hip microinstability, the provocative tests for microinstability are highly specific.

Capsular Management in Direct Anterior Total Hip Arthroplasty: A Randomized, Single-Blind, Controlled Trial

BACKGROUND

The direct anterior approach (DAA) is a popular approach to total hip arthroplasty (THA). Unlike the posterior approach, the importance of anterior capsular management is unknown. This randomized controlled trial compares capsular repair versus capsulectomy.

METHODS

This single-surgeon, single-blinded, parallel-group randomized controlled trial occurred between 2013 and 2016. Patients undergoing unilateral, primary THA for osteoarthritis consented to undergo blinded, simple randomization to anterior capsulotomy with repair or anterior capsulectomy. Primary outcome measures included hip range of motion, hip flexion strength, and pain with seated hip flexion. Secondary outcome measures included surgical time, estimated blood loss, postoperative complications, and hip disability and osteoarthritis outcome score. Data were prospectively collected intraoperatively, six weeks, six months, an average of over 5 years postoperatively.

RESULTS

Ninety-eight patients were ultimately enrolled in the trial; 50 received capsulectomy and 48 received capsulotomy. No significant differences were seen in preoperative demographics or in primary or secondary outcomes during this study. No difference was seen in pain at final follow-up at average > 5 years postoperatively.

CONCLUSION

This study demonstrates that capsular management in DAA THA does not affect postoperative pain or range of motion. The anterior capsule's role in prosthetic stability after DAA THA remains uncertain, but it does not currently appear that repair provides benefit and may lead to increased surgical time and blood loss. As such, capsular management in DAA THA is at surgeon discretion.

The effects of wearing high heeled shoes on the muscles and joints of lower limb

Study aim: The aim of this study is to investigate whether the lower extremity muscles’ force/torque/strength and range of motion may be affected in females wearing high heeled shoes and not wearing high heeled shoes.

Material and methods: The study was carried out with 136 females aged between 18 and 45 years. The first group consisted of 66 females wearing 5 cm or higher high heeled shoes. The second group consisted of 70 females wearing shoes having heel height less than 5 cm. The Nicholas Manual Muscle Tester was used to evaluate lower extremity muscle force/torque/strength, while range of motion was assessed with an electronic goniometer. The SPSS 21.0 program was used for statistical analysis.

Results: A significant difference was found in the lower extremity muscles’ force (except for hip adduction, dorsiflexion, metatarsophalangeal joint and interphalangeal joint extension), and muscles’ torque (except for hip adduction, dorsiflexion and left tibialis anterior muscle) and muscles’ strength values (except for hip adduction, dorsiflexion and tibialis anterior muscle). Also, as heel height increased, the range of motion of hip joint flexion, internal rotation and plantar flexion increased significantly.

Conclusions: Excessive use of high heeled shoes can cause changes in muscle force/torque/strength and joint range of motion.

Validity and reliability of smartphone applications for measurement of hip rotation, compared with three-dimensional motion analysis

BACKGROUND

Measurement of hip rotation is a crucial clinical parameter for the identification of hip problems and the monitoring of symptoms. The objective of this study was to determine whether the use of two smartphone applications is valid and reliable for the measurement of hip rotation.

METHODS

An experimental, cross-sectional study was undertaken to assess passive hip internal and external rotation in three positions by two examiners. The hip rotational angles were measured by a smartphone clinometer application in the sitting and prone positions, and by a smartphone compass application in the supine position; their results were compared with those of the standard, three-dimensional, motion analysis system. The validities and inter-rater and intra-rater reliabilities of the smartphone applications were evaluated.

RESULTS

The study involved 24 participants. The validities were good to excellent for the internal rotation angles in all positions (ICC 0.81-0.94), good for the external rotation angles in the prone position (ICC 0.79), and fair for the sitting and supine positions (ICC 0.70-0.73). The measurement of the hip internal rotation in the supine position had the highest ICC value of 0.94 (0.91, 0.96). The two smartphone applications showed good-to-excellent intra-rater reliability, but good-to-excellent inter-rater reliability for only three of the six positions (two other positions had fair reliability, while one position demonstrated poor reliability).

CONCLUSIONS

The two smartphone applications have good-to-excellent validity and intra-rater reliability, but only fair-to-good inter-rater reliability for the measurement of the hip rotational angle. The most valid hip rotational position in this study was the supine IR angle measurement, while the lowest validity was the ER angle measurement in the sitting position. The smartphone application is one of the practical measurements in hip rotational angles.

TRIAL REGISTRATION

Number 20181022003 at the Thai Clinical Trials Registry ( http://www.clinicaltrials.in.th ) which was retrospectively registered at 2018-10-18 15:30:29.

Influence of Standardized Procedures on the Reliability of Hip Clinical Assessment

OBJECTIVE

This study evaluated a standardized and personalized approach to verify the effects of conditions on intrarater and interrater reliability, standard error of measurement, and minimal detectable difference for provocative tests and range-of-motion (ROM) tests used in hip pain assessment: flexion-adduction-internal rotation (FADIR), flexion-abduction-external rotation-extension (FABER), and hip internal rotation with 90° of hip flexion (hip IR).

METHODS

Nineteen participants (mean [± SD] age = 24 ± 2 years; 10 women and 9 men) without lower limb or back pain were recruited. Three raters evaluated each participant during 2 testing sessions, 1 day apart. Raters performed the 3 tests in 4 conditions: classic (C), controlled pressure duration (CPD), subject-specific position (SSP), and mixed (M = CPD + SSP).

RESULTS

For intrarater reliability, the CPD condition showed the highest intraclass correlation coefficients (ICCs; mean and 95% confidence interval [CI]) for hip IR_ROM (0.83; 95% CI, 0.53-0.94) and FADIR_ROM (0.75; 95% CI, 0.60-0.89). The SSP condition showed the highest ICCs for FABER_height (0.71; 95% CI, 0.42-0.87) and FABER_ROM (0.62; 95% CI, 0.27-0.83). Concerning interrater reliability, the classic condition presented the highest ICCs for FABER variables (height: 0.54; 95% CI, 0.28-0.76; ROM: 0.58; 95% CI, 0.32-0.79) and hip IR ROM (0.72; 95% CI, 0.51-0.87). The CPD condition showed the highest ICC for FADIR_ROM (0.57; 95% CI, 0.32-0.78).

CONCLUSION

In the conditions of this study, CPD showed the highest ICCs for hip IR_ROM and FADIR_ROM, and SSP showed the highest ICCs for FABER_height and FABER_ROM.

The relationship of hip rotation range, hip rotator strength and balance in healthy individuals

BACKGROUND

Few studies have explored the relationship between muscle strength, range of motion (ROM), and balance in the horizontal plane of the hip joint using three-dimensional (3D) motion analysis.

OBJECTIVE

We investigate the relationships of hip internal rotation (IR) and external rotation (ER) ROM, measured using a 3D motion capture system, with hip internal and external rotator strength and single-leg standing balance.

METHODS

The participants were 40 healthy adults. Kinematic data on hip ROM were collected using an eight-camera motion analysis system. Hip rotational strength measurements were obtained using hand-held isometric dynamometry. A Single-leg standing test and a pendular test were conducted to evaluate static and dynamic balance ability using BioRescue.

RESULTS

Significant correlations were found between hip strength and each variable measured during hip ROM assessments (p< 0.05). Significant positive correlations were found between the hip IR/ER strength ratio and the IR/ER ROM ratio (r= 0.72, p< 0.01). The subgroup with a normal IR/ER ratio of hip rotator strength and ROM showed significantly better dynamic balance ability than the subgroup with a hip rotator muscle imbalance (p< 0.05).

CONCLUSIONS

There is a significant relationship between hip IR/ER strength and IR/ER ROM with a normal hip IR/ER strength and ROM ratio positively affecting dynamic balance ability.

Quantification and Reliability of Hip Internal Rotation and the FADIR Test in Supine Position Using a Smartphone Application in an Asymptomatic Population

OBJECTIVE

The purpose of this study was to quantify and report the intrarater and interrater reliability of hip internal rotation (IR) range of motion supine with the hip and knee at 90° of flexion and for the flexion-adduction-internal rotation (FADIR) test. Hip internal rotation measured in a lying supine position with the hip and knee at 90° of flexion revealed information on hip impairments. To date no simple quantification approach has been presented in this position; therefore, the FADIR test has not been quantified yet.

METHODS

Twenty participants (mean ± standard deviation [SD] age, 24.0 ± 2.1 years; 10 women and 10 men) without lower-limb or back pain were recruited. Three raters evaluated each participant during 2 testing sessions, 1 day apart. A built-in smartphone compass application was used to obtain the hip IR range of motion in both procedures.

RESULTS

Mean (± SD) supine IR was 51.7° (± 9.7°) and 62.6° (± 11.4°) for men and women, respectively. Concerning the FADIR test, mean values were 41.8° (± 9.64°) and 50.1° (± 8.0°) for men and women, respectively. The mean intrarater and interrater reliability coefficients were 0.80 and 0.72 for hip IR and 0.75 and 0.40 for the FADIR test. The standard error of the mean ranged from 4.8° to 8.3° (minimal detectable difference [MDD], 13.3° to 22.9°) for hip IR and from 4.6° to 10.3° (MDD, 12.8° to 28.6°) for the FADIR test.

CONCLUSION

Overall, the smartphone compass application is adequate to quantify hip IR in a lying supine position. However, the poor to moderate interrater reliability in the FADIR test and the size of the MDD values suggest that the FADIR test should be standardized.

Judokas with low back pain have lower flexibility of the hip-spine complex: A case-control study

OBJECTIVE

Study whether male adult judokas with and without low back pain (LBP) have different hip-spine flexibility.

DESIGN

Cross-sectional.

SETTING

Judo training centres.

PARTICIPANTS

Judokas with (n = 29) and without (n = 33) LBP.

MAIN OUTCOME MEASURES

Range of motion (ROM) (passive and active rotations) of hips, lumbar spine (flexion-extension) and fingertip-to-floor distance (FTFD).

RESULTS

The non-dominant hips of judokas with LBP had 6.8 ± 1.2° (ES:1.45, p < 0.001) lower passive and 8.0 ± 1.3° (ES:1.55, p < 0.001) lower active internal rotation. Dominant hips of judokas with LBP had 5.1 ± 1.6° (ES: 0.81, p = 0.002) lower active internal rotation and 8.8 ± 2.9° (ES:0.79, p = 0.003) lower active total rotation. The LBP group showed 8.0 ± 2.8° (ES: 0.73, p = 0.006) lower flexion and 6.0 ± 2.2° (ES: 0.69, p = 0.009) lower extension of the lumbar spine. The FTFD in the LBP group was 7.3 ± 2.6 cm (ES: 0.72, p = 0.007) lower. The multi-level regression analyses showed passive (OR 1.54, 95%CI 1.18-2.00, p = 0.001) and active (OR 1.47, 95%CI 1.16-1.87, p = 0.001) hip internal rotation of the non-dominant leg and lumbar spinal flexion (OR 1.11, 95%CI 1.03-1.20, p = 0.006) and extension (OR 1.16, 95%CI 1.01-1.33, p = 0.035) were related to LBP.

CONCLUSION

Lower hip internal rotation of the non-dominant leg (passive and active) and lower lumbar flexibility are significantly related to LBP in male adult judokas.

Injuries and physical characteristics affecting swimmer participation in the Olympics: A prospective survey

OBJECTIVE

To identify injuries and physical characteristics affecting swimmers' performance.

DESIGN

Prospective study.

SETTING

Laboratory-based.

PARTICIPANTS

Sixty-four Rio Olympic candidates (36 men, 28 women), who were high level swimmers ranked among the top 32 in the 2014 World Ranking in swimming. The participants were categorized into the Olympian group (n = 25), swimmers who were consecutively selected for the Olympic team, and the non-Olympian group (n = 39), swimmers who were not.

MAIN OUTCOME MEASURES

Four months prior to the Olympic qualification in 2016, an orthopedist and two physical therapists evaluated injuries and 11 physical characteristics of the swimmers. The prevalence of total overuse injuries, shoulder and low back injury, and physical characteristics were compared between the two groups.

RESULTS

The female swimmers in the non-Olympian group had a 53.3% prevalence of total overuse injuries, which was significantly higher than that of those in the Olympian group with 15.4% (p = 0.037). The prevalence of total over use injuries in male swimmers in both the Olympian and non-Olympian groups was 41.7%. Female Olympian group showed that the shoulder external rotation range of motion was significantly less than that of non-Olympian group (97.8 ± 5.7 and 103.6 ± 7.3, p = 0.046).

CONCLUSIONS

In female swimmers, total overuse injuries four months before an important competition influence their performance at the event.

Using artificial neural networks to predict impingement and dislocation in total hip arthroplasty

Dislocation after total hip arthroplasty (THA) remains a major issue and an important post-surgical complication. Impingement and subsequent dislocation are influenced by the design (head size) and position (anteversion and abduction angles) of the acetabulum and different movements of the patient, with external extension and internal flexion the most critical movements. The aim of this study is to develop a computational tool based on a three-dimensional (3D) parametric finite element (FE) model and an artificial neural network (ANN) to assist clinicians in identifying the optimal prosthesis design and position of the acetabular cup to reduce the probability of impingement and dislocation. A 3D parametric model of a THA was used. The model parameters were the femoral head size and the acetabulum abduction and anteversion angles. Simulations run with this parametric model were used to train an ANN, which predicts the range of movement (ROM) before impingement and dislocation. This study recreates different configurations and obtains absolute errors lower than 5.5° between the ROM obtained from the FE simulations and the ANN predictions. The ROM is also predicted for patients who had already suffered dislocation after THA, and the computational predictions confirm the patient's dislocations. Summarising, the combination of a 3D parametric FE model of a THA and an ANN is a useful computational tool to predict the ROM allowed for different designs of prosthesis heads.

Hip, Trunk, and Shoulder Rotational Range of Motion in Healthy Japanese Youth and High-school Baseball Pitchers

Objective

The rotational range of motion (ROM) in the upper extremities, trunk, and lower extremities is important for throwing motion. However, unlike for the shoulders, the differences relating to age and throwing-side in trunk and lower extremity ROMs in baseball pitchers are unknown. This study examined the effects of age and dominance on the ROMs of the trunk and upper and lower extremities.

Methods

The study included 356 young baseball pitchers aged 9-17 years who participated in off-season baseball camps. The subjects comprised 155 youth pitchers (aged 9-14 years) and 201 high-school pitchers (aged 15-17 years) who were able to throw at full force without pain. The neck, shoulder, trunk, and hip rotational ROMs on the dominant and non-dominant side were measured by well-trained physical therapists. The differences between throwing sides and between age groups were examined using two-way analysis of variance.

Results

Shoulder external rotation on the dominant side was greater than that on the non-dominant side. Shoulder external and internal rotational ROMs were maintained regardless of age, whereas the trunk rotational ROM significantly increased with age.

Conclusions

The effects of age and dominance on ROMs of the neck, trunk, and upper and lower extremities in Japanese youth and high-school baseball pitchers were clarified. These data could be used as a specific reference and as target values for the rehabilitation of throwing injuries in young athletes.

Clinical Predictors of Dynamic Lower Extremity Stiffness During Running

BACKGROUND

Lower extremity stiffness describes the relative loading and kinematics of the entire lower extremity during ground contact. Previously injured subjects demonstrate altered lower extremity stiffness values. Clinical analysis of lower extremity stiffness is not currently feasible due to increased time and cost.

OBJECTIVE

To determine the clinically identifiable contributors to lower extremity stiffness.

METHODS

In this cross-sectional controlled laboratory study, 92 healthy runners completed a clinical screening involving passive assessment of hip, knee, and ankle range of motion, along with body anthropometrics. The range of motion was predominantly assessed in the sagittal and frontal planes. In the same session, runners completed an overground kinematic and kinetic running assessment at 3.35 m/s (±5%) to obtain lower extremity stiffness. Correlations between lower extremity stiffness and clinical variables were completed. Modifiable variables were included in an all-possible-linear regressions approach to determine a parsimonious model for predicting lower extremity stiffness.

RESULTS

Clinically modifiable measures included in the regression model accounted for 48.4% of the variance of lower extremity stiffness during running. The variables that predicted greater stiffness included greater body mass, less ankle dorsiflexion range of motion with the knee flexed, less hip internal rotation range of motion, and less first-ray mobility.

CONCLUSION

Reduced lower extremity range of motion and greater body mass are associated with greater lower extremity stiffness during running. These variables could be addressed clinically to potentially alter lower extremity stiffness and injury risk. J Orthop Sports Phys Ther 2019;49(2):98-104. Epub 27 Jul 2018. doi:10.2519/jospt.2019.7683.

Range limitation in hip internal rotation and fifth metatarsal stress fractures (Jones fracture) in professional football players

PURPOSE

To identify unknown risk factors associated with fifth metatarsal stress fracture (Jones fracture).

METHODS

A case-controlled study was conducted among male Japanese professional football (soccer) players with (N = 20) and without (N = 40) a history of Jones fracture. Injury history and physical examination data were reviewed, and the two groups were compared. Univariate and multivariate logistic regression controlling for age, leg dominance and body mass index were used to obtain odds ratios (ORs) and 95% confidence intervals (CIs) to describe the association between physical examination data and the presence or absence of Jones fractures.

RESULTS

From 2000 to 2014, among 162 professional football club players, 22 (13.6%; 21 Asians and one Caucasian) had a history of Jones fracture. Thirteen out of 22 (60%) had a Jones fracture in their non-dominant leg. The mean range of hip internal rotation (HIR) was restricted in players with a history of Jones fracture [25.9° ± 7.5°, mean ± standard deviation (SD)] compared to those without (40.4° ± 11.1°, P < 0.0001). Logistic regression analyses demonstrated that HIR limitation increased the risk of a Jones fracture (OR = 3.03, 95% CI 1.45-6.33, P = 0.003). Subgroup analysis using data prior to Jones fracture revealed a causal relationship, such that players with a restriction of HIR were at high risk of developing a Jones fracture [Crude OR (95% CI) = 6.66 (1.90-23.29), P = 0.003, Adjusted OR = 9.91 (2.28-43.10), P = 0.002]. In addition, right HIR range limitation increased the risks of developing a Jones fracture in the ipsilateral and the contralateral feet [OR = 3.11 (1.35-7.16) and 2.24 (1.22-4.12), respectively]. Similarly, left HIR range limitation increased the risks in the ipsilateral or the contralateral feet [OR (95% CI) = 4.88 (1.56-15.28) and 2.77 (1.08-7.08), respectively].

CONCLUSION

The restriction of HIR was associated with an increased risk of developing a Jones fracture. Since the HIR range is a modifiable factor, monitoring and improving the HIR range can lead to prevent reducing the occurrence of this fracture.

LEVEL OF EVIDENCE

III.

Normative Values of Physical Examinations Commonly Used for Cerebral Palsy

PURPOSE

The aim of this study was to establish normative values and to identify age-related change in physical examinations that are commonly used while evaluating patients with cerebral palsy (CP).

MATERIALS AND METHODS

One hundred four healthy volunteers (mean age 36 years, standard deviation 15 years) were enrolled and divided into four age groups: 13-20, 21-35, 36-50, and 51 years and older. The eighteen physical examination tests for CP were selected by five orthopedic surgeons in consensus-building session. The measurements were taken by three orthopedic surgeons.

RESULTS

There was no significant difference in the measures of physical examination among all the age groups, except for the Staheli test (p=0.002). The post hoc test revealed that the mean hip extension was 2.7° higher in the 13-20-year-old group than in the other age groups. The bilateral popliteal angle had a tendency to increase in those over 36-years-old. There were 31 participants (30%) with a unilateral popliteal angle greater than 40°.

CONCLUSION

We documented normative values that can be widely used for evaluating CP in patients 13 years and older.

Restricted Hip Rotation Is Correlated With an Increased Risk for Anterior Cruciate Ligament Injury

PURPOSE

The primary purpose was to compare ipsilateral hip internal rotation (IR) in male and female athletes with or without an anterior cruciate ligament (ACL) tear. A secondary purpose was to compare radiographic markers of femoroacetabular impingement (FAI) in patients with or without an ACL tear.

METHODS

In this prospective case-control study, based on a power analysis, a convenience sample of 25 ACL-injured and 25 control patients matched by age and gender were examined over 14 months. The ACL injury group included preoperative patients 12-40 years old with an ACL rupture within the previous 3 months with no prior lower extremity injuries, ligamentous laxity, or arthralgias. Controls included patients presenting with an upper extremity complaint with no history of knee injury. In the outpatient clinic, hip axial rotation range of motion was measured with a goniometer on physical examination and hip radiographs were evaluated for morphologic variations consistent with FAI. Univariate analysis of variance was used to examine differences between groups.

RESULTS

Each group had 13 males and 12 females, average ages of 22.8 ± 7.2 years (ACL group) versus 24.5 ± 7.9 years (controls; P = .439). The average sum of hip rotation (internal plus external) in patients with an ACL tear was 60.3 ± 12.4° compared with 72.6 ± 17.2° in controls (P = .006). ACL-injured patients had decreased hip IR compared with controls, with respective mean measurements of 23.4 ± 7.6° versus 30.4 ± 10.4° (P = .009). For every 10° increase in hip IR, the odds of having an ACL tear decreased by a factor of 0.419 (P = .015).

CONCLUSIONS

Risk of ACL injury is associated with restricted hip IR, and as hip IR increases, the odds of having an ACL tear decreases. In addition, ACL injury is associated with FAI in a generalized population of male and female athletes, although causality cannot be determined and most ACL-injured patients do not exhibit hip complaints.

LEVEL OF EVIDENCE

Level II, prognostic, prospective cohort study.

Ipsilateral patterns of the rotational range of motion of the hip in healthy Japanese adults

[Purpose] This study aimed to categorize the internal and external rotation range of motion (ROM) of ipsilateral hip joints into specific patterns based on the differences between them, and clarify the distribution of these patterns. [Subjects and Methods] A total of 222 healthy Japanese medical students (162 males, 60 females) with a mean age of 21.2 ± 4.0 years were enrolled. The ROM of internal and external rotation at the hip were randomly measured with the subjects in the prone position. Thereafter, the difference between internal and external rotations was assessed. Hip ROM patterns were classified into 3 types based on the differences in the rotation ROM on each side. A total of 9 overall patterns were then determined based on the combination of patterns on both sides. [Results] Although all the subjects were healthy, an asymmetrical ROM between internal and external rotation in ipsilateral hip joints could be detected via pattern classification. Moreover, the distribution of each hip ROM pattern was clarified. [Conclusion] Pattern classification based on differences in internal and external rotation ROM could serve as a useful evaluation method for clinical manipulative therapy.

Effect of General Anesthesia on Preoperative Hip Range of Motion in Patients Undergoing Hip Arthroscopy

The purpose of this study was to investigate the effect of general anesthesia on preoperative passive hip range of motion (ROM) in patients undergoing hip arthroscopy for various indications. A total of 260 consecutive patients undergoing hip arthroscopy were included in this study. Passive hip ROM was evaluated bilaterally in the clinic and subsequently under general anesthesia immediately preoperatively. Demographic variables, including age, height, weight, and clinical diagnosis, were recorded for all patients. Hips with pincer-type femoroacetabular impingement (FAI) and hips with acetabular dysplasia showed a mean increase of 4° and 6°, respectively, in hip external rotation at 90° of hip flexion (ER-90) with induction of anesthesia (P=.018 and P=.021, respectively). In contrast, a statistically significant reduction in hip abduction (2°) and hip flexion (4°) was observed following induction of anesthesia in healthy contralateral hips of patients presenting with unilateral hip pathology (P=.01 and P<.001, respectively). Hip ROM does not change to a clinically significant extent with induction of general anesthesia. Small increases in external rotation in patients with FAI or acetabular dysplasia are within the standard error for ROM measurements. [Orthopedics. 2016; 39(6):e1165-e1169.].

Is there any range-of-motion advantage to using bearings larger than 36mm in primary hip arthroplasty: A case-control study comparing 36-mm and large-diameter heads

BACKGROUND

Large-diameter (>36mm) total hip arthroplasty (THA) has developed rapidly since the advent of ceramic-on-ceramic (CoC) bearings and highly cross-linked polyethylene. Theoretically, the increase in diameter reduces the risk of instability, although the advantage of calibers beyond 36mm has not been demonstrated in terms of range-of-motion recovery. We conducted a comparative study with a single prosthesis model to determine whether increasing the caliber beyond 36mm provides: (1) better recovery of range-of-motion, (2) a higher functional score, and (3) reduction of the dislocation rate.

HYPOTHESIS

Increasing the range-of-motion by increasing the caliber beyond 36mm provides better range-of-motion.

MATERIAL AND METHODS

We analyzed two consecutive, single-operator cementless THA series performed via the mini posterior approach, which differed only in the bearing system (51 metal-on-metal [MoM] with a mean caliber of 45mm±3.3 [range, 40-54] and 61 CoC with a 36-mm caliber). Both series were comparable preoperatively in terms of age, diagnosis, functional scores, preoperative range-of-motion, body mass index, UCLA activity level, and Charnley score. We compared the joint range of movement at follow-up and the gains in range of movement, onset of dislocation, and functional scores (Oxford, Postel-Merle d'Aubigné [PMA]).

RESULTS

The mean overall joint range-of-motion was 254°±39° (range, 150-310°) for an 81°±44° (range, -50 to 180°) gain in the MoM group and 256°±23° (range, 200-280°) for an 84°±40° (range, 0-160°) gain in the CoC group (NS). The MoM group presented the following results: Oxford=13.71±3.66 (range, 12-33) for a gain of 24.82 points±7.9 (range, -1 to 40), PMA=17.75±1.06 (range, 11-18) for a gain of 7.78 points±4.01 (range, 2-15). The CoC group had: Oxford=14.98±4.42 (range, 12-36) for a gain of 24.75 points±6.55 (range, 12-40), PMA 17.66±0.7 (range, 14-18) for a gain of 8 points±3.77 (range, 1-15). None of the gains and scores at follow-up differed significantly between the two groups. No episode of dislocation was identified.

DISCUSSION

The current trend of increasing femoral head diameters beyond 36mm to improve the gains in joint range-of-motion and function is not warranted. The potential side effects of increasing the caliber call for even greater caution in the use of large-diameter heads because our hypothesis has not been confirmed.

LEVEL OF EVIDENCE

Case-control study, level III.

Lumbar Thrust Manipulation and Exercise for the Treatment of Mechanical Low Back Pain in Adolescents: A Case Series

Study Design Case series. Background Low back pain (LBP) is an increasing problem in health care. The evidence for the use of spinal manipulative therapy to treat pediatric patients with LBP is minimal. The treatment of pediatrics with manual therapy, particularly spinal manipulation, is controversial within the medical community, primarily with respect to adverse events. The purpose of this case series was to illustrate the feasibility and safety of lumbar manipulation plus exercise in the adolescent population with mechanical LBP. Case Description Three patients-a 13-year-old adolescent girl, 15-year-old adolescent girl, and 13-year-old adolescent boy-were treated in an outpatient physical therapy setting for mechanical LBP. All 3 patients were assessed using a lumbar manipulation clinical prediction rule and treated with sidelying lumbar manipulation and exercise. Outcomes Patients were treated for a total of 10 to 14 visits over a course of 8 to 9 weeks. Pain (measured by a numeric pain-rating scale) and disability (measured by the modified Oswestry Disability Index) improved to 0/10 and 0%, respectively, in each patient. No adverse reactions to manipulation were reported. Discussion The results of this case series describe the use of lumbar thrust manipulation and exercise for the treatment of mechanical LBP in adolescents. The positive results indicate that lumbar manipulation may be a safe adjunct therapy. Further studies, including randomized controlled trials, are needed to determine effectiveness. Level of Evidence Therapy, level 4. J Orthop Sports Phys Ther 2016;46(5):391-398. Epub 6 Apr 2016. doi:10.2519/jospt.2016.6366.

Hip rotation range of motion in sitting and prone positions in healthy Japanese adults

[Purpose] The aim of this study was to elucidate the difference in hip external and internal rotation ranges of motion (ROM) between the prone and sitting positions. [Subjects] The subjects included 151 students. [Methods] Hip rotational ROM was measured with the subjects in the prone and sitting positions. Two-way repeated measures analysis of variance (ANOVA) was used to analyze ipsilateral hip rotation ROM in the prone and sitting positions in males and females. The total ipsilateral hip rotation ROM was calculated by adding the measured values for external and internal rotations. [Results] Ipsilateral hip rotation ROM revealed significant differences between two positions for both left and right internal and external rotations. Hip rotation ROM was significantly higher in the prone position than in the sitting position. Hip rotation ROM significantly differed between the men and women. Hip external rotation ROM was significantly higher in both positions in men; conversely, hip internal rotation ROM was significantly higher in both positions in women. [Conclusion] Hip rotation ROM significantly differed between the sexes and between the sitting and prone positions. Total ipsilateral hip rotation ROM, total angle of external rotation, and total angle of internal rotation of the left and right hips greatly varied, suggesting that hip joint rotational ROM is widely distributed.

Relationship Between Tightness of the Hip Joint and Elbow Pain in Adolescent Baseball Players

Background:

Repetitive tensile stresses from valgus torque can induce elbow injury in adolescent baseball players. Insufficient hip range of motion (ROM) can change throwing mechanics, reducing the transfer of energy from the lower to the upper extremities. Thus, hip ROM limitations may force the upper extremities to bear the burden of a strong throw. Improper pitching mechanics caused by insufficient hip ROM are thought to increase valgus torque on the elbow when throwing, increasing the risk of elbow injury.

Purpose:

To investigate the relationship between elbow pain and hip ROM in adolescent baseball players.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

A total of 122 adolescent baseball players with a mean age of 12.0 years (range, 6-14 years) participated in this study. Elbow pain, hip flexion angle, and the internal rotation angles of the hip at 0° and 90° of flexion were assessed. Participants were divided into a pain group and a normal group based on the pain assessment, and each hip angle was compared between groups using Student t tests. P values <.05 were considered statistically significant.

Results:

Thirty-one of 122 players had elbow pain. The hip flexion angle of the trail leg was 121.9° ± 12.3° for the normal group and 111.2° ± 11.3° for the pain group (P = .0001). The plant leg hip flexion angles were 122.0° ± 12.4° and 113.6° ± 11.3° (P = .0014) for the normal and pain groups, respectively. The internal rotation angle at 0° of hip flexion of the trail leg was 49.4° ± 12.6° and 45.6° ± 8.8° (not significant), and of the plant leg was 49.1° ± 12.5° and 48.7° ± 11.5° (not significant), for the normal and pain groups, respectively. The internal rotation of the trail leg at 90° of hip flexion was 46.9° ± 13.3° in the normal group and 36.1° ± 15.7° in the pain group (P = .0005). In the plant leg, the internal rotation angle at 90° of hip flexion was 46.9° ± 12.2° and 36.4° ± 18.1° for the normal and pain groups, respectively (P = .0013).

Conclusion:

Limitations to hip flexion and internal rotation at 90° of hip flexion were risk factors for elbow injury. Differences in internal rotation angles between 0° and 90° of hip flexion may be important criteria for identifying adolescent baseball players at risk of elbow pain.

Evaluation of preoperative hip range of motion under general anaesthesia

Hip range of motion (ROM) may be an important preoperative variable, however, measurement of hip ROM can be affected by various factors. The purposes of this study were to compare conventional preoperative ROM measurements with those measurements obtained under general anaesthesia, and to better define the associations between preoperative hip ROM, and demographic, functional, and diagnostic variables.
Conventional preoperative hip ROM and ROM under general anaesthesia were prospectively measured in 471 hips. Harris pain score, the Crowe classification, and the diagnosis were also investigated. 
The hip ROM in all directions under general anaesthesia was significantly greater than conventional preoperative hip ROM. There were correlations between conventional preoperative hip ROM and the Harris hip pain score. Hip ROM with Crowe type I deformity under anaesthesia was significantly greater than in hips with type II, III or IV. ROM under anaesthesia of osteonecrosis hips was significantly greater than osteoarthritis and dislocated hips. Conventional preoperative ROM in men was greater in flexion and external rotation compared to women. Internal rotation motion in women in both conventional preoperative ROM and ROM under anaesthesia was greater than in men. 
Hip pain, Crowe classification and diagnosis could influence preoperative hip ROM. Measurement of hip ROM under general anaesthesia could better reflect true ROM compared to measurement without anaesthesia.

Clinical anatomy of the pelvis and hip

The contents of this review may appear odd. After a brief description of the coxofemoral joint, the entities discussed include ilioinguinal neuropathy within the context of the nerves that may be damaged during lower abdominal surgery, meralgia paresthetica, piriformis syndrome with the appropriate caveats, trochanteric syndrome, "ischial bursitis" and trochanteric syndrome caused by ischemia. These cases were chosen to stress our belief that rheumatologists are first and foremost internists. We further believe that being current in other pathologies such as peripheral neuropathies and certain vascular syndromes sooner or later benefits our patients.