Effect of Increased Scapular Internal Rotation on Glenohumeral External Rotation and Elbow Valgus Load in the Late Cocking Phase of Throwing Motion

2018 ◽  
Vol 46 (13) ◽  
pp. 3182-3188 ◽  
Author(s):  
Yasuo Itami ◽  
Teruhisa Mihata ◽  
Michelle H. McGarry ◽  
Charles C. Lin ◽  
Nilay A. Patel ◽  
...  
Keyword(s):  
Internal Rotation ◽  
External Rotation ◽  
Ulnar Collateral Ligament ◽  
Testing System ◽  
Scapular Dyskinesis ◽  
Kinetic Chain ◽  
Valgus Angle ◽  
Joint Gap ◽  
Intact Condition ◽  
Fresh Frozen

Background: Scapular dyskinesis among throwers is thought to affect kinetic chain function and increase the load demands on the shoulder and/or elbow. However, the biomechanical relationship between scapular orientation and elbow valgus load, which is associated with ulnar collateral ligament (UCL) injury, has not been determined. Purpose: To evaluate the effect of increased scapular internal rotation (IR) and glenohumeral external rotation (GHER) on elbow valgus load in a static simulation of the late cocking phase of throwing. Study Design: Controlled laboratory study. Methods: Seven fresh-frozen male cadaveric upper extremities were used with a custom testing system to simulate the late cocking phase. First, the authors evaluated the effect of increasing scapular IR on maximum GHER and forearm angle (forearm axis relative to the ground). Each parameter was evaluated at 20° to 40° (5° increments) of scapular IR by applying 2.2-N·m external rotation torque to the humerus and 0.75-N·m valgus torque to the forearm. Next, to evaluate elbow valgus stability, the humerus was locked in maximal GHER at 40° of scapular IR, and sequentially increasing torque (0.75-7.5 N·m by 0.75-N·m increments) was applied to the forearm. Valgus angle and joint gap were evaluated at each torque. Results: Increases in scapular IR ≥5° significantly decreased GHER ( P < .01). With increasing valgus torque, forearm angle also increased linearly ( R2 = 0.85, P < .001). To compensate for the GHER deficit at 40° of scapular IR, a linear regression model showed that 25.3 N·m of valgus torque would be necessary to reach the original forearm position. In the intact condition, applying elbow valgus torque ≥5.25 N·m significantly increased valgus angle and the joint gap ( P < .01). Conclusion: Increased scapular IR significantly decreased GHER. Compensation for the GHER deficit significantly increased the elbow valgus load required to reach the same forearm position. Clinical Relevance: Increased scapular IR may increase the risk of elbow UCL injury among throwing athletes.

Medial Posterior Capsular Plication Reduces Anterior Shoulder Instability Similar to Remplissage Without Restricting Motion in the Setting of an Engaging Hill-Sachs Defect

2017 ◽  
Vol 45 (9) ◽  
pp. 1982-1989 ◽  
Author(s):  
Brian C. Werner ◽  
Xiang Chen ◽  
Christopher L. Camp ◽  
Andreas Kontaxis ◽  
Joshua S. Dines ◽  
...  
Keyword(s):  
Internal Rotation ◽  
External Rotation ◽  
Biomechanical Testing ◽  
Bankart Repair ◽  
Anterior Shoulder Instability ◽  
Anterior Translation ◽  
Capsular Plication ◽  
Fresh Frozen ◽  
Surgical Options ◽  
Joint Loads

Background: Numerous surgical options for the management of engaging Hill-Sachs lesions exist, of which remplissage has emerged as one of the most popular arthroscopic techniques. Remplissage is not without disadvantages, however, and has been demonstrated to potentially result in a loss of external rotation (ER) due to nonanatomic tethering of the infraspinatus tendon and a potential decrease in infraspinatus strength clinically. Purpose: The efficacy of posterior medial capsular plication in addition to Bankart repair was examined as an arthroscopic management strategy for an engaging Hill-Sachs defect. Study Design: Controlled laboratory study. Methods: Eight fresh-frozen human cadaveric shoulders were utilized for the study. After testing baseline translation and motion, 30% Hill-Sachs lesions were created in each specimen. Three experimental groups were assembled: (1) isolated Bankart repair (HSD), (2) Bankart repair with remplissage (RM), and (3) Bankart repair with posterior medial capsular plication (PL). Biomechanical testing was performed to determine anterior translation, range of motion, and Hill-Sachs engagement. Translation and motion measurements were normalized to the baseline laxity values for each specimen. Results: A significant reduction in anterior translation was noted at 60° of abduction and 60° of ER for both the PL and RM groups compared with the HSD group throughout most of the joint loads tested ( P < .05), but no significant differences were noted between the PL and RM groups at any load. The RM group had significantly less normalized ER at 60° of abduction compared with the HSD and PL groups ( P < .05). There were no differences in internal rotation between the groups. All 8 specimens in the HSD group engaged, while no specimens in the RM and PL groups engaged ( P < .001). Conclusion: In a cadaveric model, medial posterior capsular plication as an adjunct to Bankart repair offers similar resistance to anterior translation and Hill-Sachs engagement as compared with remplissage in the setting of an engaging Hill-Sachs defect. Medial posterior capsular plication results in less restriction of ER compared with remplissage without any significant limitation of internal rotation. Clinical Relevance: Posterior medial capsular plication reduces translation and engagement similarly to remplissage, without any restriction in motion.

Biomechanical Measurements of Torsion-Tension Coupling in Human Cadaveric Femurs

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
Rad Zdero ◽  
Alison J. McConnell ◽  
Christopher Peskun ◽  
Khalid A. Syed ◽  
Emil H. Schemitsch
Keyword(s):  
Internal Rotation ◽  
External Rotation ◽  
Tensile Load ◽  
Strong Relationship ◽  
Strongly Coupled ◽  
Axial Tensile ◽  
Applied Torque ◽  
Two Factors ◽  
Fresh Frozen ◽  
Rotation Groups

The mechanical behavior of human femurs has been described in the literature with regard to torsion and tension but only as independent measurements. However, in this study, human femurs were subjected to torsion to determine if a simultaneous axial tensile load was generated. Fresh frozen human femurs (n=25) were harvested and stripped of soft tissue. Each femur was mounted rigidly in a specially designed test jig and remained at a fixed axial length during all experiments. Femurs were subjected to external and internal rotation applied at a constant angulation rate of 0.1 deg/s to a maximum torque of 12 N m. Applied torque and generated axial tension were monitored simultaneously. Outcome measurements were extracted from torsion-versus-tension graphs. There was a strong relationship between applied torsion and the resulting tension for external rotation tests (torsion/tension ratio=551.7±283.8 mm, R2=0.83±0.20, n=25), internal rotation tests (torsion/tension ratio=495.3±233.1 mm, R2=0.87±0.17, n=24), left femurs (torsion/tension ratio=542.2±262.4 mm, R2=0.88±0.13, n=24), and right femurs (torsion/tension ratio=506.7±260.0 mm, R2=0.82±0.22, n=25). No statistically significant differences were found for external versus internal rotation groups or for left versus right femurs when comparing torsion/tension ratios (p=0.85) or R2 values (p=0.54). A strongly coupled linear relationship between torsion and tension for human femurs was exhibited. This suggests an interplay between these two factors during activities of daily living and injury processes.

scholarly journals Serratus Anterior Stretch: A Novel Intervention and Its Effect on the Shoulder Range of Motion

2020 ◽  
pp. 1-4
Author(s):  
Keramat Ullah Keramat ◽  
Mohammad Naveed Babar
Keyword(s):  
Range Of Motion ◽  
Internal Rotation ◽  
External Rotation ◽  
Scapular Dyskinesis ◽  
Serratus Anterior ◽  
Shoulder Dysfunction ◽  
Shoulder Range Of Motion ◽  
Before And After ◽  
Movement Screening ◽  
Shoulder Range

Context: Serratus anterior tightness is associated with scapular dyskinesis and overall shoulder dysfunction, which affects the range of motion. The most effective intervention to stretch the serratus anterior is unknown. Objective: To evaluate the effect of a therapist-administered novel serratus anterior stretch (SAS) on shoulder range of motion. Method: This study recruited 30 healthy subjects of age 21.20 (1.69) years, height 1.65 (0.11) m, and weight 60.90 (10.36) kg in equal ratio of males and females who scored 1 or 2 on the shoulder mobility test of functional movement screening. A single intervention of a novel SAS was applied to the shoulder. Outcome variables before and after the SAS included the following: shoulder ROM (flexion, abduction, internal rotation, and external rotation) and functional movements of reaching up behind the back and reaching down behind the neck. Results: A paired t test was used to analyze the data. Following the acute SAS intervention, all shoulder ROM improved significantly (P < .000). The change in internal rotation was 6.00° (7.47°), external rotation was 5.66° (9.35°), abduction was 13.50° (11.82°), flexion was 20° (13.33°), reaching up behind the back was 5.10 (2.21) cm, and reaching down behind the neck was 5.41 (2.89) cm. The most marked improvement was in reaching up behind the back (24.48%) and reaching down behind the neck (22.78%). A very large effect size (>1) was observed across most of the variables. Conclusion: An acute SAS intervention improves shoulder mobility in healthy individuals. It is recommended for the trial on the prevention and rehabilitation of shoulder pathologies with restriction in shoulder mobility.

scholarly journals Internal Rotation and Scapular Position Differences: A Comparison of Collegiate and High School Baseball Players

2010 ◽  
Vol 45 (1) ◽  
pp. 44-50 ◽  
Author(s):  
Stephen J. Thomas ◽  
Kathleen A. Swanik ◽  
Charles B. Swanik ◽  
John D. Kelly
Keyword(s):  
High School ◽  
Internal Rotation ◽  
Glenohumeral Joint ◽  
External Rotation ◽  
Scapular Dyskinesis ◽  
Position Change ◽  
Baseball Players ◽  
Glenohumeral Internal Rotation Deficit ◽  
Rotator Cuff Injuries ◽  
Collegiate Baseball

Abstract Context: Conditions such as labral and rotator cuff injuries have been linked with decreases in glenohumeral internal-rotation and increases in external-rotation motion. Also, decreased glenohumeral internal rotation is strongly associated with scapular dyskinesis. Objective: To compare healthy collegiate and high school baseball players' glenohumeral joint range of motion and scapular position. Design: Cross-sectional study. Setting: Institutional research laboratory. Patients or Other Participants: Thirty-one male National Collegiate Athletic Association Division I collegiate (age  =  20.23 ± 1.17 years, height  =  186.24 ± 5.73 cm, mass  =  92.01 ± 7.68 kg) and 21 male high school baseball players (age  =  16.57 ± 0.76 years, height  =  180.58 ± 6.01 cm, mass  =  79.09 ± 11.51 kg). Main Outcome Measure(s): Glenohumeral internal and external rotation and scapular upward rotation were measured with a digital inclinometer. Scapular protraction was measured with a vernier caliper. All variables except scapular upward rotation were calculated as the difference between the dominant and nondominant sides. Results: Collegiate baseball players had more glenohumeral internal-rotation deficit (4.80°, P  =  .028) and total motion deficit (5.73°, P  =  .009) and less glenohumeral external-rotation gain (3.00°, P  =  .028) than high school players. Collegiate baseball players had less scapular upward rotation than high school players at the 90° (4.12°, P  =  .015, versus 3.00°, P  =  .025) and 120° (4.00°, P  =  .007, versus 3.40°, P  =  .005) positions. The scapular protraction difference was greater in collegiate baseball players than in high school players in the hands-on-hips and 90° positions (0.77 cm, P  =  .021, and 1.4 cm, P  =  .001). Conclusions: When comparing high school with collegiate baseball players, these data suggest that glenohumeral internal-rotation deficit and scapular position change as the level of competition increases.

Legal Update: North Dakota Supreme Court: Third Edition of Guides is “Most Current”

1999 ◽  
Vol 4 (1) ◽  
pp. 6-7
Author(s):  
James J. Mangraviti
Keyword(s):  
Internal Rotation ◽  
External Rotation ◽  
Measurement Techniques ◽  
Fourth Edition ◽  
Hip Motion ◽  
The Difference ◽  
The Right ◽  
Hip Flexion ◽  
Hip Rotation ◽  
Hip Extension

Abstract The accurate measurement of hip motion is critical when one rates impairments of this joint, makes an initial diagnosis, assesses progression over time, and evaluates treatment outcome. The hip permits all motions typical of a ball-and-socket joint. The hip sacrifices some motion but gains stability and strength. Figures 52 to 54 in AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Fourth Edition, illustrate techniques for measuring hip flexion, loss of extension, abduction, adduction, and external and internal rotation. Figure 53 in the AMA Guides, Fourth Edition, illustrates neutral, abducted, and adducted positions of the hip and proper alignment of the goniometer arms, and Figure 52 illustrates use of a goniometer to measure flexion of the right hip. In terms of impairment rating, hip extension (at least any beyond neutral) is irrelevant, and the AMA Guides contains no figures describing its measurement. Figure 54, Measuring Internal and External Hip Rotation, demonstrates proper positioning and measurement techniques for rotary movements of this joint. The difference between measured and actual hip rotation probably is minimal and is irrelevant for impairment rating. The normal internal rotation varies from 30° to 40°, and the external rotation ranges from 40° to 60°.

Força dos Músculos Rotadores do Ombro em Indivíduos Saudáveis/ Rotator Cuff Muscle Strength in Healthy Individuals

1970 ◽  
Vol 1 (1) ◽  
pp. 78-82
Author(s):  
Paulo José Oliveira Cortez ◽  
José Elias Tomazini ◽  
Mauro Gonçalves
Keyword(s):  
Rotator Cuff ◽  
Muscle Strength ◽  
Internal Rotation ◽  
Upper Limb ◽  
Statistical Difference ◽  
External Rotation ◽  
Healthy Individuals ◽  
Average Strength ◽  
Strength Tests ◽  
The Right

Introdução: A diminuição da capacidade de exercer esforços por parte dos músculos rotadores pode criar uma variedade de problemas. O conhecimento preciso do nível de força muscular de um indivíduo é importante, tanto para a avaliação da capacidade funcional ocupacional, como para uma apropriada prescrição de exercícios atléticos e de reabilitação. Percebe-se escassez de informação sobre as articulações do ombro, bem como os fatores envolvidos na força muscular dessa região. O objetivo deste estudo foi comparar a força gerada pelos músculos do manguito rotador entre o membro superior direito e o membro superior esquerdo em indivíduos saudáveis. Métodos: Participaram do estudo 22 sujeitos do sexo masculino, com idade de 18 e 19 anos, militares, saudáveis e sem história clínica de patologia ortopédica ou qualquer tipo de lesão no sistema musculoesquelético. Foram aplicados dois testes de força: Rotação Interna e Rotação Externa. Resultado : A força média de rotação interna no membro superior direito (MSD) foi maior que a força média de rotação interna no membro superior esquerdo (MSE) (p=0,723) e a força de rotação externa no MSD foi menor que a força média de rotação externa no MSE (p=0,788). Não houve diferença estatística na comparação dos valores de força de todos os testes de força isométrica. Conclusão: Para amostra estudada e metodologia utilizada na avaliação da força muscular, não houve diferença estatística na comparação da força gerada pelos músculos do manguito rotador do membro superior direito e do membro superior esquerdo.Rotator Cuff Muscle Strength in Healthy Individuals Introduction: Decreased ability to exert efforts by the rotator muscles can create a variety of problems. The precise knowledge of the level of muscular strength of an individual is important for both the functional capacity evaluation for occupational as an appropriate exercise prescription and rehabilitation of athletic. It is perceived scarcity of information on the shoulder joints as well as factors involved in muscle strength in this region. Objective: Develop a device for measuring the strength generated by the muscles of the upper limbs and the verification of efficiency and adaptability of this device through a comparative study of muscle strength in healthy subjects. Methods: The study included 22 male subjects, aged 18 and 19 years, military personnel, body mass between 57.7 and 93 kg (71.8 ± 9.45 kg) and height between 1.67 and 1.90 m (1.75 ± 0.06 m), healthy and without a history of orthopaedic disease or any kind of damage to the musculoskeletal system. Three strength tests were applied: Internal Rotation and External Rotation. For each type of effort three maximum voluntary contractions were required for 10 seconds, with an interval of 30 seconds between each contraction.  Results: Internal rotation in the right upper limb (RUL) was higher than the average strength of internal rotation in the left upper limb (LUL) (p = 0, 723) and the external rotation strength in RUL was lower than the average strength of external rotation in the LUL (p=0,788).  No statistical difference in comparing the strength values of all isometric strength tests. Conclusion: For sample and methodology used to assess muscle strength, there was no statistical difference in comparing the force generated by the muscles of the rotator cuff of the right and left upper limb.

scholarly journals Acromioclavicular joint reconstruction implants have differing ability to restore horizontal and vertical plane stability

2021 ◽  
Author(s):  
Mohamed Alkoheji ◽  
Hadi El-Daou ◽  
Jillian Lee ◽  
Adrian Carlos ◽  
Livio Di Mascio ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Acromioclavicular Joint ◽  
Vertical Plane ◽  
Testing System ◽  
Bonferroni Correction ◽  
Joint Reconstruction ◽  
Fresh Frozen ◽  
Robotic Testing ◽  
Robotic Testing System ◽  
Anterior Posterior

Abstract Purpose Persistent acromioclavicular joint (ACJ) instability following high grade injuries causes significant symptoms. The importance of horizontal plane stability is increasingly recognised. There is little evidence of the ability of current implant methods to restore native ACJ stability in the vertical and horizontal planes. The purpose of this work was to measure the ability of three implant reconstructions to restore native ACJ stability. Methods Three groups of nine fresh-frozen shoulders each were mounted into a robotic testing system. The scapula was stationary and the robot displaced the clavicle to measure native anterior, posterior, superior and inferior (A, P, S, I) stability at 50 N force. The ACJ capsule, conoid and trapezoid ligaments were transected and the ACJ was reconstructed using one of three commercially available systems. Two systems (tape loop + screw and tape loop + button) wrapped a tape around the clavicle and coracoid, the third system (sutures + buttons) passed directly through tunnels in the clavicle and coracoid. The stabilities were remeasured. The data for A, P, S, I stability and ranges of A–P and S–I stability were analyzed by ANOVA and repeated-measures Student t tests with Bonferroni correction, to contrast each reconstruction stability versus the native ACJ data for that set of nine specimens, and examined contrasts among the reconstructions. Results All three reconstructions restored the range of A–P stability to that of the native ACJ. However, the coracoid loop devices shifted the clavicle anteriorly. For S–I stability, only the sutures + buttons reconstruction did not differ significantly from native ligament restraint. Conclusions Only the sutures + buttons reconstruction, that passed directly through tunnels in the clavicle and coracoid, restored all stability measures (A, P, S, I) to the native values, while the tape implants wrapped around the bones anteriorised the clavicle. These findings show differing abilities among reconstructions to restore native stability in horizontal and vertical planes. (300 words)

Chronic Adaptations of the Posterior Rotator Cuff in Professional Pitchers

2021 ◽  
pp. 036354652098868
Author(s):  
Stephen J. Thomas ◽  
Justin Cobb ◽  
Scott Sheridan ◽  
Joseph Rauch ◽  
Ryan W. Paul
Keyword(s):  
Soft Tissue ◽  
Rotator Cuff ◽  
Internal Rotation ◽  
External Rotation ◽  
Negative Relationship ◽  
Muscle Thickness ◽  
Pennation Angle ◽  
Muscle Architecture ◽  
Infraspinatus Muscle ◽  
Teres Minor

Background: Because of the large forces and high frequency of throwing, the upper extremity experiences repetitive stresses that lead to acute and chronic adaptations. While the importance of pennation angle and muscle thickness as predictors of muscle force production has been shown in other populations and other joints, there has been little research done that examines these variables in the shoulders of baseball players. Purpose: (1) To examine the chronic effect pitching has on the rotator cuff muscle architecture (pennation angle and muscle thickness) in healthy professional baseball pitchers, and (2) to examine the correlation between muscle architecture and clinical measures of strength and range of motion (ROM). Study Design: Cross-sectional study; Level of evidence, 3. Methods: Twenty-eight healthy professional pitchers were recruited during the 2019 spring training. Internal rotation (IR) and external rotation (ER) strength were measured with a handheld dynamometer and IR and ER ROM were measured with an inclinometer. A diagnostic ultrasound machine was utilized to capture images of humeral retroversion, as well as the pennation angle and muscle thickness of the infraspinatus and teres minor muscles. ImageJ software was used to quantify the pennation angle and muscle thickness. Results: There were no significant differences between the dominant and nondominant arms for ER or IR strength. Also, no pennation angle and muscle thickness differences were found between the dominant and nondominant arms. A weak positive relationship between infraspinatus muscle thickness (superficial and total) and ER strength ( P = .016, R = 0.287 and P = .009, R = 0.316) and a moderate negative relationship between soft tissue glenohumeral internal rotation deficit (GIRD) and the bilateral difference of the teres minor deep pennation angle ( R = −0.477, P = .008) were observed. No other significant relationships were noted. Conclusion: Our results are contrary to current literature as we expected to see a stronger dominant arm, with a larger pennation angle and greater muscle thickness. Interestingly, we found that ER strength was positively related to only the thickness of the infraspinatus muscle, and that soft tissue GIRD was positively related to only the side-to-side adaptation of the pennation angle within the deep portion of the teres minor. This suggests that when posterior shoulder tightness occurs, specifically the architecture of the teres minor muscle is involved. However, the organization to which these players belonged has a very extensive training protocol throughout the year that emphasizes bilateral training during a large majority of the exercises. Therefore, the results may not be generalizable to all professional players.

scholarly journals Delayed Rehabilitation Protocol after Rotator Cuff Repair

Osteology ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 29-38
Author(s):  
Alessandra Berton ◽  
Sergio De Salvatore ◽  
Vincenzo Candela ◽  
Gabriele Cortina ◽  
Daniela Lo Presti ◽  
...  
Keyword(s):  
Rotator Cuff ◽  
Muscle Strength ◽  
Internal Rotation ◽  
Outcome Measures ◽  
Rotator Cuff Repair ◽  
External Rotation ◽  
Shoulder Function ◽  
Rehabilitation Protocol ◽  
Patient Reported ◽  
Cuff Repair

Rotator cuff tears are a frequent cause of shoulder pain that often require arthroscopic repair. After surgery an intense and well-studied rehabilitation protocol is needed to obtain the complete recovery of shoulder function. Fifty patients, who sustained arthroscopic rotator cuff repair for symptomatic, atraumatic and full-thickness supraspinatus tendon tear, were involved. According to our rehabilitation protocol, during the first four postoperative weeks, the arm was supported with an abduction sling pillow, and pendulum exercises, table slide and active elbow extension and flexion were conceded. Outcome measures (Oxford shoulder score (OSS), simple shoulder test (SST), patient-reported satisfaction), shoulder function (range of motion (ROM) and muscle strength), and MRI examination were evaluated. The mean OSS score and SST score increased from 16 to 30.2 and from 5.3 to 11.4, respectively. Patient-reported satisfaction was 96%. At 12 months, patients improved ROM and muscle strength. Postoperative passive anterior elevation was 176; external rotation averaged 47; internal rotation was 90. Postoperative muscle strength during anterior elevation was 8.3 ± 2.2 kg, internal rotation 6.8 ± 3 kg, external rotation 5.5 ± 2.3 kg. Five out of seven patients with recurrent tears evaluated their results as satisfactory. They reported improvements in terms of OSS and SST mean scores despite recurrent tears; therefore, they did not undergo revision surgery. The delayed postoperative physical therapy protocol was associated with improvements in the outcome measures and shoulder function compared to the preoperatory state and rotator cuff healing demonstrated by MRI.

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

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Phob Ganokroj ◽  
Nuchanun Sompornpanich ◽  
Pichitpol Kerdsomnuek ◽  
Bavornrat Vanadurongwan ◽  
Pisit Lertwanich
Keyword(s):  
Internal Rotation ◽  
Motion Analysis ◽  
Supine Position ◽  
External Rotation ◽  
Three Dimensional ◽  
Angle Measurement ◽  
Smartphone Applications ◽  
Rater Reliability ◽  
Link Type ◽  
Hip Rotation

Abstract 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.

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