Cardan angle rotation sequence effects on first-metatarsophalangeal joint kinematics: implications for measuring hallux valgus deformity

BACKGROUND: There currently are no recommended standards for reporting kinematics of the first-metatarsophalangeal joint. This study compared 2 different rotation sequences of Cardan angles, with implications for understanding the measurement of hallux valgus deformity. METHODS: Thirty-one women (19 hallux valgus; 12 controls) participated. All were scanned in an open-upright magnetic resonance scanner, their foot posed to simulate the gait conditions of midstance, heel-off, and terminal stance. Using computer processes, selected tarsals were reconstructed into virtual bone models and embedded with principal-axes coordinate systems, from which the rotation matrix between the hallux and first metatarsal was decomposed into Cardan angles. Joint angles were then compared using a within factors (rotation sequence and gait condition) repeated-measures analysis of variance (ANOVA). RESULTS: Only the transverse plane-first sequence consistently output incremental increases of dorsiflexion and abduction across gait events in both groups. There was an interaction (F ≥ 25.1; p < 0.001). Follow-up comparisons revealed angles were different (p < 0.05) at terminal stance. CONCLUSIONS: Different rotation sequences yield different results. Extracting the first rotation in the transverse plane allows for the resting alignment of the hallux to deviate from the sagittal plane. Therefore, representing first-metatarsophalangeal joint kinematics with the transverse plane-first rotation sequence may be preferred, especially in cases of hallux valgus deformity

An Assessment of the World's Contribution to Spine Trauma Care: A Bibliometric Analysis of Classifications and Surgical Management; An AO Spine Knowledge Forum Trauma Initiative.

STUDY DESIGN Bibliometric analysis. OBJECTIVES An analysis of the literature related to the assessment and management of spinal trauma was undertaken to allow the identification of top contributors, collaborations and research trends. METHODS A search to identify original articles published in English between 2011 and 2020 was done using specific keywords in the Web of Science database. After screening, the top 300 most cited articles were analyzed using Biblioshiny R software. RESULTS The highest number of contributions were from the Thomas Jefferson University, USA, University of Toronto and University of British Columbia, Canada. The top 3 most prolific authors were Vaccaro AR, Arabi B, and Oner FC. The USA and Canada were among the top contributing countries; Switzerland and Brazil had most multiple country co-authored articles. The most relevant journals were the European Spine Journal, Spine and Spine Journal. Three of the 5 most cited articles were about classification systems of fractures. The keyword analysis included clusters for different spinal regions, spinal cord injury, classification agreement and reliability studies, imaging related studies, surgical techniques and outcomes. CONCLUSIONS The study identified the most impactful authors and affiliations, and determined the journals where most impactful research is published in the field. Study also compared the productivity and collaborations across countries. The study highlighted the impact of development of new classification systems, and identified research trends including instrumentation, fixation and decompression techniques, epidemiology and recovery after spinal trauma

Study of scapular muscle latency, shoulder kinematics and muscle activity in people with and without shoulder impingement.

University of Minnesota Ph.D. dissertation. August 2009. Major: Rehabilitation Science. Advisor: Paula M Ludewig, PT, PhD. 1 computer file (PDF); xiv, 250 pages, appendices 1-16. Ill. (some col.)Background and significance: Shoulder impingement is a common shoulder pathology which is associated with changes in kinematics and muscle activity around the shoulder joint. The changes in muscle activity are theorized to be caused by changes in motor program strategies controlling the smooth and coordinated movements at the joints. Changes in muscle latencies, especially feed forward contractions, indicate alterations in these motor control programs. The purpose of the study was to assess for differences in the latencies and deactivation times of scapular muscles between subjects with and without shoulder impingement. Research Methods: Twenty five healthy subjects and 24 subjects with impingement were recruited. Scapulothoracic and glenohumeral kinematic data were collected using an electromagnetic system. Simultaneously myoelectric activities using surface electrodes from upper trapezius, lower trapezius, serratus anterior and anterior fibers of deltoid were collected as subjects raised and lowered their arm in response to a light cue. Data was collected during unloaded, loaded and after performing repetitive arm raising motion conditions. Analysis: The ratios of the number of feedforward contractions during trials were compared by chi square analysis across groups and conditions. The other variables were analyzed using 2 or 3 way mixed model ANOVAs. Results: The percentage of trials showing feed forward contractions was higher for upper trapezius and lower trapezius in the unloaded condition and lower for serratus anterior in the condition after repetitive motion for the subjects with impingement as compared to healthy subjects. Subjects with impingement also demonstrated significantly earlier contraction of upper trapezius and an earlier deactivation of serratus anterior during lowering of the arm as compared to the healthy subjects. All subjects exhibited an earlier activation and delayed deactivation of lower trapezius and serratus anterior in conditions with a weight held in hand. The study found decreased scapular upward rotation, decreased posterior tilt and a less anterior plane of elevation in combination in subjects with impingement using logistic regression analysis. No significant group differences were found for muscle activity as a percentage of the reference contraction. Discussion and conclusions: The subjects with impingement showed some significant differences for muscle activation and deactivation times to indicate differences in motor control strategies. Rehabilitation measures should incorporate appropriate training measures in tandem with strengthening and stretching exercises to focus on improving movement patterns and muscle control

Motion of the Shoulder Complex During Multiplanar Humeral Elevation

Background: Many prior studies have evaluated shoulder motion, yet no three-dimensional analysis comparing the combined clavicular, scapular, and humeral motion during arm elevation has been done. We aimed to describe and compare dynamic three-dimensional motion of the shoulder complex during raising and lowering the arm across three distinct elevation planes (flexion, scapular plane abduction, and coronal plane abduction)