• Dynamic time warping
• Inertial measurement unit
• Kinematics
• Rehabilitation
• Scapula
• Similarity

• Humans
• Male
• Middle Aged
• Female
• Biomechanical Phenomena
• Shoulder Pain/physiopathology
• Prospective Studies
• Adult
• Pilot Projects
• Shoulder Impingement Syndrome/physiopathology
• Shoulder/physiopathology
• Aged
• Scapula/physiopathology
• Range of Motion, Articular

• Arm elevation
• EOS
• Kinematics
• Posture
• Spine

• Humans
• Female
• Male
• Adult
• Young Adult
• Posture/physiology
• Spine/diagnostic imaging
• Spine/physiology
• Arm/diagnostic imaging
• Arm/physiology
• Lordosis/diagnostic imaging
• Biomechanical Phenomena/physiology
• Movement/physiology

• Glenohumeral
• Postoperative
• Range of motion
• Rehabilitation
• Shoulder
• Stiffness

• Dynamic
• Scapulohumeral rhythm
• Shoulder
• Static
• Three-dimensional analysis

• scapula
• serve
• shoulder injury
• taping
• tennis

• Biomechanical Phenomena
• Humans
• Movement
• Range of Motion, Articular
• Scapula
• Shoulder Joint
• Shoulder Pain/therapy
• Tennis

Scapular dyskinesis is reported as one of the potential factors contributing to the presentation of pain in subacromial shoulder pain. In clinical practice, the evaluation and control of scapular dyskinesis is considered important for managing the subacromial shoulder pain. The aim is to determine the association between changes in pain or function and changes in scapular rotations in participants with subacromial shoulder pain.

Pain, function and scapular rotations were measured in 25 participants with subacromial shoulder pain at baseline and after 8 weeks. Pain was measured with Numeric Pain Rating Scale (NPRS) and function was measured with Patient Specific Functional Scale (PSFS). Scapular rotations were measured with a scapular locator at 60°, 90° and 120° of scapular arm elevation. Spearman rank correlations (r_s) were used to assess the association between variables.

No association was observed between changes in pain or function scores with changes in scapular upward/downward rotations (r_s = 0.03 to 0.27 for pain and − 0.13 to 0.23 for function) and scapular anterior/posterior tilt (r_s = − 0.01 to 0.23 for pain and − 0.13 to 0.08 for function) of arm at 60°, 90° and 120° elevation. Data associated with scapular internal/external rotation was not reported due to low reliability.

These findings reject associations between changes in pain or function scores and scapular rotations. Future observational study is warranted using a multifactorial approach to understand potential factors that contribute to the presentation of subacromial shoulder pain.

• 3D motion analysis
• Complication
• Contact forces
• Kinematic
• Reverse shoulder arthroplasty
• Scapulohumeral rhythm

• Arthroplasty
• Glenohumeral
• Regression analysis
• Replacement
• Scapula
• Shoulder joint

• Biomechanical Phenomena
• Humans
• Motion
• Movement
• Range of Motion, Articular
• Upper Extremity

Digital home rehabilitation systems require accurate segmentation methods to provide appropriate feedback on repetition counting and exercise technique. Current segmentation methods are not suitable for clinical use; they are not highly accurate or require multiple sensors, which creates usability problems. We propose a model for accurately segmenting inertial measurement unit data for shoulder rehabilitation exercises. This study aims to use inertial measurement unit data to train and test a machine learning segmentation model for single- and multiple-inertial measurement unit systems and to identify the optimal single-sensor location.

A focus group of specialist physiotherapists selected the exercises, which were performed by participants wearing inertial measurement units on the wrist, arm and scapula. We applied a novel machine learning based segmentation technique involving a convolutional classifier and Finite State Machine to the inertial measurement unit data. An accuracy score was calculated for each possible single- or multiple-sensor system.

The wrist inertial measurement unit was chosen as the optimal single-sensor location for future system development (mean overall accuracy 0.871). Flexion and abduction based exercises mostly could be segmented with high accuracy, but scapular movement exercises had poor accuracy.

A wrist-worn single inertial measurement unit system can accurately segment shoulder exercise repetitions; however, accuracy varies depending on characteristics of the exercise.

• Segmentation
• home rehabilitation
• inertial measurement unit
• machine learning
• shoulder

• Coordinate system
• Joint angles
• Scapula
• Shoulder
• Transformations

• Biomechanical Phenomena
• Female
• Humans
• Male
• Middle Aged
• Reproducibility of Results
• Scapula/physiopathology

• UL1 RR025764 NCRR NIH HHS
• UL1 TR002538 NCATS NIH HHS
• R01 AR067196 NIAMS NIH HHS
• UL1 TR000105 NCATS NIH HHS
• UL1 TR001067 NCATS NIH HHS

• Consistency and Reliability
• Kinematics
• Scapula

• Acromioclavicular Joint/physiology
• Adult
• Biomechanical Phenomena/physiology
• Data Analysis
• Female
• Humans
• Male
• Movement/physiology
• Range of Motion, Articular/physiology
• Rotation
• Scapula/physiology
• Shoulder/physiology
• Shoulder Impingement Syndrome/physiopathology
• Shoulder Pain/physiopathology
• Sternoclavicular Joint/physiology
• Thorax/physiology

• P41 EB027061 NIBIB NIH HHS
• F31 HD087069 NICHD NIH HHS
• UL1 TR002494 NCATS NIH HHS
• T32 AR050938 NIAMS NIH HHS
• L30 HD089226 NICHD NIH HHS
• P41 EB015894 NIBIB NIH HHS
• NIH

• Human movement understanding
• Human-robot interaction
• Kinematics
• Robot-assisted rehabilitation
• Shoulder

• 2D-3D model-based registration
• Asynchronous image acquisition
• Bead tracking
• Clinical biplane fluoroscopic systems
• Interpolation
• Kinematics

• arm elevation
• brassiere
• electromagnetic tracking device
• shoulder kinematics

• Accuracy
• Clinical biplane
• Computed tomography
• Fluoroscopy
• Kinematics
• Model-based tracking
• Radiostereometric analysis
• Shoulder
• Validation

• 3D kinematics
• Rotation
• Scapula
• Total shoulder arthroplasty
• Translation

• 3D analysis
• Acceleration
• Biomechanics

Failure of the scapulohumeral rhythm (SHR) is observed in patients with shoulder joint dysfunction. The SHR reportedly has a 2:1 ratio during scapular upward rotation with arm elevation. However, three-dimensional scapular motion analysis has indicated variations in this ratio according to the arm elevation angle. We observed 2 distinct patterns: the scapular upward rotation decreased after knot formation (type I) or increased after knot formation (type II) during arm elevation. In the present study, we aimed to identify the knot and investigate the influence of varying external loads on this kinesiological change point.

We evaluated 35 healthy adult men (35 dominant-side shoulders) with a mean age of 20 ± 1.7 years (mean height: 172 ± 6.4 cm, mean weight: 65.7 ± 5.8 kg). Participants performed scapular plane elevation with no load or with an external load (1–5 kg) while sitting on a chair. The measured scapular upward rotation values were interpolated using the spline function and fitted to line graphs, and the change in these values was compared for various loads.

The estimated knot angles (standard error) in the no load condition, and with external loads of 1, 2, 3, 4, and 5 kg were 83.5 (2.9°), 81.2 (2.9°), 81.0 (2.9°), 76.1 (2.9°), 73.4 (3.1°), and 75.8 (3.1°), respectively. No significant difference was noted in the knot position at 1–2 kg (vs. unloaded), although the knot was significantly lower at 3–5 kg (3 kg: p = 0.01, 4 kg: p = 0.001, and 5 kg: p = 0.02). Moreover, we observed that participants either exhibited increased or decreased upward rotational momentum after knot formation.

Our results confirm that the kinesiological change point (the knot) during scapular upward rotation occurred at lower angles in cases of increasing external loads.

• External load
• Kinesiological change point
• Knot
• Scapular upward rotation
• Three-dimensional motion analysis

The shoulder complex presents unique challenges for measuring motion as the scapula, unlike any other bony segment in the body, glides and rotates underneath layers of soft tissue and skin. The ability for clinicians and researchers to collect meaningful kinematic data is dependent on the reliability and validity of the instrumentation utilized. The aim of this study was to review the relevant literature pertaining to the reliability and validity of electromagnetic tracking systems (ETS) and digital inclinometers for assessing shoulder complex motion. Advances in technology have led to the development of biomechanical instrumentation, like ETS, that allow for the collection of three-dimensional kinematic data. The existing evidence has demonstrated that ETS are reliable and valid instruments for collecting static and dynamic kinematic data of the shoulder complex. Similarly, digital inclinometers have become increasingly popular among clinicians due to their cost effectiveness and practical use in the clinical setting. The existing evidence supports the use of digital inclinometers for the collection of shoulder complex kinematics as these instruments have been demonstrated to yield acceptable reliability and validity. While digital inclinometers pose a disadvantage to ETS regarding accuracy, precision, and are limited to two-dimensional and static measurements, this instrument provides clinically meaningful data that allow clinicians and researchers the ability to measure, monitor, and compare shoulder complex kinematics.

• Biomechanics
• Glenohumeral
• Kinematics
• Reliability
• Scapulothoracic
• Validity

• kinematics
• scapulohumeral rhythm
• shoulder joint
• supraspinatus muscle

• Active
• Dynamic
• Motion analysis
• Passive
• Shoulder
• Static

Overhead athletic activities and scapula dyskinesia are linked with shoulder pathology; pull-ups are a common training method for some overhead sports. Different pull-up techniques exist: anecdotally some are easier to perform, and others linked to greater incidences of pathology. This study aims to quantify scapular kinematics and external forces for three pull-up techniques, thus discussing potential injury implications.

An observational study was performed with eleven participants (age = 26.8 ± 2.4 years) who regularly perform pull-ups.

The upward motions of three pull-up techniques were analysed: palms facing anterior, palms facing posterior and wide-grip. A skin-fixed scapula tracking technique with attached retro-reflective markers was used.

High intra-participant repeatability was observed: mean coefficients of multiple correlations of 0.87–1.00 in humerothoracic rotations and 0.77–0.90 for scapulothoracic rotations. Standard deviations of hand force was low: <5% body weight. Significantly different patterns of humerothoracic, scapulothoracic and glenohumeral kinematics were observed between the pull-up techniques. The reverse technique has extreme glenohumeral internal–external rotation and large deviation from the scapula plane. The wide technique has a reduced range of pro/retraction in the same HT plane of elevation and 90° of arm abduction with 45° external rotation was observed. All these factors suggest increased sub-acromial impingement risk.

The scapula tracking technique showed high repeatability. High arm elevation during pull-ups reduces sub-acromial space and increases pressure, increasing the risk of impingement injury. Wide and reverse pull-ups demonstrate kinematics patterns linked with increased impingement risk. Weight-assisted front pull-ups require further investigation and could be recommended for weaker participants.

• Biomechanics
• Kipping
• Repeatability
• Shoulder
• Skin-fixed scapula tracking
• Supraspinatus

• 3D
• gender
• humerus
• joint
• motion analysis
• scapula
• shoulder

Patients who have shoulder pain usually have compensatory or contributory deviation of shoulder motion during arm elevation. In the traditional scapulohumeral rhythm, the share of the acromioclavicular (AC) and the sternoclavicular (SC) joint movements and also the role of AC internal rotation angle are unknown.

The main purpose of this study was to measure and compare the segmentary scapulohumeral rhythm (SSHR) during scapular arm elevation at a steady rotational speed in athletes with and without impingement syndrome.

Using a speedometer, the maximum speed of arm elevation was measured in 21 men in each of the involved and uninvolved groups. Using fluoroscopy on the dominant side, SSHR during scapular arm elevation at a rotational speed equal to 1/30 of maximum speed was compared between the two groups. The ratio of glenohumeral (GH) elevation angle to AC rotation angle in the scapular plane was considered as SSHR.

The maximum speed of arm elevation between the two groups was significantly different (P < 0.001). The rhythm of the involved group significantly exceeded the rhythm of the uninvolved group in a part of the first quarter range of the arm elevation. SSHR during arm elevation in the uninvolved group did not change significantly (P = 0.845); however, it decreased significantly in the involved group (P = 0.024).

Speed differences between the two groups were probably due to the pain in some ranges of arm elevation. SSHR in the involved group probably changed in order to compensate downward rotation of the scapula in the resting position. Study of the AC upward rotation range can be misleading; therefore, the study of scapulohumeral rhythm is recommended.

• Acromioclavicular Joint
• Biomechanical Phenomena
• Shoulder Impingement Syndrome

• Clavicle
• Kinematics
• Protraction
• Scapula rotation

• Adult
• Arm/physiology
• Biomechanical Phenomena
• Clavicle/physiology
• Female
• Healthy Volunteers
• Humans
• Imaging, Three-Dimensional
• Male
• Middle Aged
• Movement/physiology
• Principal Component Analysis
• Range of Motion, Articular/physiology
• Rotation
• Scapula/physiology

• 3D
• Scapula
• dominance
• gender
• kinematics
• posture
• shoulder

• Athletic
• Motion analysis
• Scapula tracking
• Shoulder
• Speed
• Upper limb

• Bootstrap
• Motion analysis
• Prediction
• Scapular kinematics
• Shoulder

• Kinematics
• Long thoracic nerve
• Scapular winging
• Shoulder
• Spinal accessory nerve

• Accessory Nerve Diseases/complications
• Adult
• Biomechanical Phenomena
• Female
• Humans
• Male
• Middle Aged
• Movement/physiology
• Range of Motion, Articular/physiology
• Rotation
• Scapula/abnormalities
• Scapula/physiopathology
• Shoulder/physiopathology
• Shoulder Impingement Syndrome/etiology
• Shoulder Impingement Syndrome/physiopathology
• Thoracic Outlet Syndrome/complications

Evaluate the static positioning of the scapula on the rib cage in healthy subjects by means of clinical and radiographic evaluation to assess inter-examiner reliability of clinical examination and verify the reliability of this evaluation method compared to the radiographic examination.

We selected 30 adult individuals of both sexes with no diagnosis of shoulder pathology. The static clinical examination, following the protocol suggested by Burkhart et al, was performed repeatedly by two independent examiners, followed by the radiographic examination, which was later examined by the first evaluator.

73.3% of the subjects showed positioning of the scapula considered normal. The inter-examiner reliability and that of the clinical examination in relation to radiography were considered low and very low, respectively.

The reproducibility of the evaluation performed by Burkhart was considered satisfactory to good, while the inter-examiner reproducibility of the clinical examination and the static reproducibility of the clinical examination with radiography were considered poor to satisfactory. Level of Evidence III, Study of Nonconsecutive Patients.

• Evaluation
• Humans
• Radiography
• Scapula

• 3D scapular kinematics
• Activities of daily living
• Repeatability

• Adult
• Biomechanical Phenomena
• Humans
• Imaging, Three-Dimensional
• Male
• Models, Biological
• Movement/physiology
• Radiography
• Scapula/diagnostic imaging
• Scapula/physiology
• Video Recording