Impact of tendon transfer on scapulothoracic and glenohumeral motion in children with brachial plexus birth injuries.

Background: Tendon transfers are often utilized to improve shoulder external rotation and abduction in children with brachial plexus birth injuries and are designed to improve glenohumeral (GH) joint motion. However, changes in scapulothoracic (ST) and GH joint function after tendon transfer are not well defined. The purpose of this study was to quantify changes in GH, ST, and humerothoracic (HT) joint function before and after tendon transfer, and we hypothesized that tendon transfers would reorient the arc of motion into more external rotation and abduction, but not increase GH motion.

Assessment of approaches to estimate scapular orientation in children with brachial plexus birth injury.

Background: Challenges in measuring dynamic scapular orientation limit assessment of scapulothoracic and glenohumeral contributions to shoulder function in children with brachial plexus birth injury (BPBI). Double calibration acromion marker cluster (D-AMC) and linear model approaches have been validated to estimate scapular motion in healthy adults, but neither has been evaluated in BPBI.

Research Question: Are the linear model and D-AMC approaches able to accurately estimate scapular orientation in children with BPBI at functional arm postures?

Methods: Seventeen children with BPBI positioned their affected limbs in 11 static positions while their segment orientations were measured with motion capture.

Reachable workspace with real-time motion capture feedback to quantify upper extremity function: A study on children with brachial plexus birth injury.

Clinical upper extremity (UE) functional assessments and motion capture measures are limited to a set of postures and/or motions that may provide an incomplete evaluation of UE functionality. Reachable workspace analysis offers a more global assessment of UE function, but is reliant on patient compliance with instructions and may result in underestimates of a patient's true UE function. This study evaluated a clinical tool that incorporates real-time visual feedback with motion capture to provide an innovative means of engaging patients to ensure a 'best effort' quantification of their available UE workspace.

Scapulothoracic and Glenohumeral Contributions to Humerothoracic Kinematics in Single Versus Double Tendon Transfers in Patients With Brachial Plexus Birth Injury.

Purpose: Evidence suggests that patients with brachial plexus birth injury are more likely to retain midline function following a teres major tendon transfer without a concomitant latissimus dorsi transfer. Both procedures increase shoulder external rotation and abduction, but whether increased loss of midline frequency following double transfer is due to glenohumeral (GH) joint motion or scapulothoracic (ST) compensation is unknown. We hypothesized that double tendon transfers would exhibit greater GH external rotation than single tendon transfers, thus requiring greater ST rotation to internally rotate the shoulder, while GH and ST contributions to elevation remained equivalent between both groups.

Effect of Glenohumeral Reduction Type Combined With Tendon Transfer for Brachial Plexus Injury on Objective, Functional, and Patient-Reported Outcomes.

Purpose: Glenohumeral (GH) joint reductions are frequently performed during tendon transfer surgery for brachial plexus birth injuries (BPBI); however, the effect of reduction method (none required, closed, surgical) has not been assessed. This study compared objective, functional, and patient-reported outcomes between children who underwent a tendon transfer and (1) did not require GH reduction, (2) required concomitant closed GH reduction, or (3) required concomitant surgical GH reduction.

Methods: Fifty-four children with BPBI who previously underwent teres major and/or latissimus dorsi transfer with or without concomitant GH reduction participated.

Assessment of the relationship between Brachial Plexus Profile activity short form scores and modified Mallet scores.

Introduction: This study aims to assess the relationship between the modified Mallet classification and the Brachial Plexus Profile activity short form (BP-PRO activity SF). The therapist or surgeon classifies upper extremity movement for the modified Mallet classification, while the BP-PRO assesses parents' perceptions of difficulty performing activities.

Purpose: To provide a deeper understanding of the relationship of functional and perceived outcome measurements.

A comparison of currently available optoelectronic motion capture systems.

The measurement of human motion relies heavily on the ability of the optoelectronic motion capture systems to accurately measure retroreflective marker positions. Marker position accuracy is largely dependent on the optical characteristics of the camera system and algorithms implemented in the tracking software. In 1999, Richards critically reviewed multiple camera systems and each of their ability to generate the same marker coordinate positions under different field tests.

Machine learning algorithms for predicting scapular kinematics.

The goal of this study was to develop and validate a non-invasive approach to estimate scapular kinematics in individual patients. We hypothesized that machine learning algorithms could be developed using motion capture data to accurately estimate dynamic scapula orientation based on measured humeral orientations and acromion process positions. The accuracy of the algorithms was evaluated against a gold standard of biplane fluoroscopy using a 2D to 3D fluoroscopy/model matching process.

Analysis of Shoulder Complex Function After Posterior Spinal Fusion in Adolescents With Idiopathic Scoliosis.

Background: Nonsurgically treated patients with AIS demonstrate altered scapular kinematics and decreased patient-reported shoulder function compared with typically developing adolescents. It is unknown whether surgical correction of the spine deformity has beneficial or detrimental effects on scapulothoracic joint function, as previous assessments of shoulder function following surgery have only focused on humerothoracic motion. The objective of this study was to perform a comprehensive analysis of scapular kinematics before and after PSF and compare postoperative scapular kinematics in AIS to those of a typically developing cohort.

Scapular Stabilization Limits Glenohumeral Stretching in Children With Brachial Plexus Injuries.

Purpose: To quantify the effects of scapular stabilization on scapulothoracic and glenohumeral (GH) stretching.

Methods: Motion capture data during external rotation and abduction with and without scapular stabilization were collected and analyzed for 26 children with brachial plexus birth palsy. These positions were performed by an experienced occupational therapist and by the child's caretaker.

A Comprehensive Method to Measure 3-Dimensional Bra Motion During Physical Activity.

Breast and bra motion research aims to understand how the breasts/bra move to aid development of apparel that minimizes motion. Most previously published research has tracked nipple motion to represent bra motion. However, this method does not provide information regarding regional tissue motion.

Motion Necessary to Achieve Mallet Internal Rotation Positions in Children With Brachial Plexus Birth Palsy.

Background: Upper extremity function in children with brachial plexus birth palsy (BPBP) is assessed with clinical tests such as the Mallet classification, which uses a hand to spine position to assess shoulder internal rotation, or the modified Mallet classification, which adds an additional internal rotation task (hand to belly). Children with BPBP frequently have difficulty performing the hand to spine task. This study compared scapulothoracic and glenohumeral (GH) parameters associated with successful completion of the hand to spine and hand to belly modified Mallet positions.

A comparison of two non-invasive methods for measuring scapular orientation in functional positions.

Identification of scapular dyskinesis and evaluation of interventions depend on the ability to properly measure scapulothoracic (ST) motion. The most widely used measurement approach is the acromion marker cluster (AMC), which can yield large errors in extreme humeral elevation and can be inaccurate in children and patient populations. Recently, an individualized regression approach has been proposed as an alternative to the AMC.

Errors Associated With Utilizing Prescribed Scapular Kinematics to Estimate Unconstrained, Natural Upper Extremity Motion in Musculoskeletal Modeling.

Musculoskeletal modeling is capable of estimating physiological parameters that cannot be directly measured, however, the validity of the results must be assessed. Several models utilize a scapular rhythm to prescribe kinematics, yet it is unknown how well they replicate natural scapular motion. This study evaluated kinematic errors associated with a model that employs a scapular rhythm using 2 shoulder movements: abduction and forward reach.

Efficacy of 3 therapeutic taping configurations for children with brachial plexus birth palsy.

Study Design: Cross-sectional clinical measurement study.

Introduction: Scapular winging is a frequent complaint among children with brachial plexus birth palsy (BPBP). Therapeutic taping for scapular stabilization has been reported to decrease scapular winging.

Validation of a mathematical approach to estimate dynamic scapular orientation.

The goal of this study was to develop and validate a non-invasive approach to estimate scapular kinematics in individual patients. We hypothesized that individualized mathematical algorithms can be developed using motion capture data to accurately estimate dynamic scapula orientation based on measured humeral orientations and acromion process positions. The accuracy of the mathematical algorithms was evaluated against a gold standard of biplane fluoroscopy using a 2D to 3D fluoroscopy/model matching process.

Determining 3D scapular orientation with scapula models and biplane 2D images.

This study evaluated a strategy for identifying 3D scapulothoracic orientation using bilateral X-ray scans and 3D scapula models. Both subject-specific scapula models and a scaled general model were utilized. 3D scapulothoracic orientations obtained from X-rays were compared to motion capture data.

Biomechanical analysis of gait termination in 11-17year old youth at preferred and fast walking speeds.

In populations where walking and/or stopping can be difficult, such as in children with cerebral palsy, the ability to quickly stop walking may be beyond the child's capabilities. Gait termination may be improved with physical therapy. However, without a greater understanding of the mechanical requirements of this skill, treatment planning is difficult.

A comparison of acromion marker cluster calibration methods for estimating scapular kinematics during upper extremity ergometry.

Accurate measurement of joint kinematics is required to understand the musculoskeletal effects of a therapeutic intervention such as upper extremity (UE) ergometry. Traditional surface-based motion capture is effective for quantifying humerothoracic motion, but scapular kinematics are challenging to obtain. Methods for estimating scapular kinematics include the widely-reported acromion marker cluster (AMC) which utilizes a static calibration between the scapula and the AMC to estimate the orientation of the scapula during motion.

Increasing plantarflexion angle during landing reduces vertical ground reaction forces, loading rates and the hip's contribution to support moment within participants.

The ankle joint's role in shock absorption during landing has been researched in many studies, which have found that landing with higher amounts of plantarflexion (PF) results in lower peak vertical ground reaction forces and loading rates. However, there has not yet been a study that compares drop landings within participants along a quantitative continuum of PF angles. Using a custom-written real-time feedback program, participants adjusted their ankles to an instructed PF angle and dropped onto two force platforms.

Limited glenohumeral cross-body adduction in children with brachial plexus birth palsy: a contributor to scapular winging.

Background: Approximately 1 of every 1000 live births results in life-long impairments because of a brachial plexus injury. The long-term sequelae of persistent injuries include glenohumeral joint dysplasia and glenohumeral internal rotation and adduction contractures. Scapular winging is also common, and patients and their families often express concern regarding this observed scapular winging.