James E. Robb

Bio: James E. Robb is an academic researcher from University of St Andrews. The author has contributed to research in topics: Gait analysis & Cerebral palsy. The author has an hindex of 29, co-authored 81 publications receiving 2454 citations. Previous affiliations of James E. Robb include Princess Margaret Rose Orthopaedic Hospital & Astley Ainslie Hospital.

Edinburgh visual gait score for use in cerebral palsy.

Abstract: Complex gait analysis systems are not generally available worldwide, and no simple system of assessing gait by observation has been validated specifically for use in patients with cerebral palsy. The authors have developed a visual gait analysis score for use in cerebral palsy. Videotaped sequences of patients were recorded before and after surgery as part of a three-dimensional gait study using a Vicon (Oxford, U.K.) gait analysis system. The score demonstrated good intraobserver and interobserver reliability. The numeric values of the score elements correlated well with the measurements obtained from instrumented gait analysis for the same patients, and the score was able to detect postoperative change.

Electrophysiological responses of human bone cells to mechanical stimulation: evidence for specific integrin function in mechanotransduction.

Abstract: Bone cells respond to mechanical stimuli, but the transduction mechanisms responsible are not fully understood. Integrins, a family of heterodimeric transmembrane glycoproteins, which link components of the extracellular matrix with the actin cytoskeleton, have been implicated as mechanoreceptors. We have assessed the roles of integrins in the transduction of cyclical mechanical stimuli to human bone cells (HBCs), which results in changes in membrane potential. HBC showed membrane depolarization following 0.104 Hz mechanical stimulation and membrane hyperpolarization following stimulation at 0.33 Hz. The membrane depolarization response involved tetrodotoxin-sensitive sodium channels and could be inhibited by antibodies against alpha V, beta 1, and beta 5 integrins. In contrast, the hyperpolarization response was inhibited by gadolinium and antibodies to the integrin-associated protein (CD47), alpha 5 and beta 1 integrin. Both responses could be abrogated by ARg-Gly-Asp (RGD)-containing peptides, inhibition of tyrosine kinase activity, and disruption of the cytoskeleton. These results demonstrate differential electrophysiological responses of HBC to different frequencies of mechanical strain. Furthermore, they suggest that integrins act as HBC mechanoreceptors with distinct signaling pathways being activated by different frequencies of mechanical stimuli.

Management of completely displaced metaphyseal fractures of the distal radius in children. A prospective, randomised controlled trial.

Abstract: In a prospective, randomised controlled trial, 68 children who had a completely displaced metaphyseal fracture of the distal radius were treated either by manipulation (MUA) and application of an above-elbow cast alone or by the additional insertion of a percutaneous Kirschner (K-) wire. Full radiological follow-up to union was obtained in 65 children and 56 returned for clinical evaluation three months after injury. Maintenance of reduction was significantly better in the K-wire group and fewer follow-up radiographs were required. There was no significant difference in the clinical outcome measured three months after injury. Seven of 33 patients in the MUA group had to undergo a second procedure because of an unacceptable position compared with none of the 35 in the K-wire group (chi-squared test, p < 0.01). One patient in the K-wire group required exploration for recovery of a migrated wire. We conclude that the use of a percutaneous K-wire to augment the reduction of the fracture in children who have a completely displaced metaphyseal fracture of the distal radius is a safe and reliable way of maintaining alignment of the fracture.

Gait analysis using wearable sensors.

Abstract: Gait analysis using wearable sensors is an inexpensive, convenient, and efficient manner of providing useful information for multiple health-related applications. As a clinical tool applied in the rehabilitation and diagnosis of medical conditions and sport activities, gait analysis using wearable sensors shows great prospects. The current paper reviews available wearable sensors and ambulatory gait analysis methods based on the various wearable sensors. After an introduction of the gait phases, the principles and features of wearable sensors used in gait analysis are provided. The gait analysis methods based on wearable sensors is divided into gait kinematics, gait kinetics, and electromyography. Studies on the current methods are reviewed, and applications in sports, rehabilitation, and clinical diagnosis are summarized separately. With the development of sensor technology and the analysis method, gait analysis using wearable sensors is expected to play an increasingly important role in clinical applications.

Mechanotransduction in bone--role of the lacuno-canalicular network.

Abstract: The capacity of bone tissue to alter its mass and structure in response to mechanical demands has long been recognized but the cellular mechanisms involved remained poorly understood. Over the last several years significant progress has been made in this field, which we will try to summarize. These studies emphasize the role of osteocytes as the professional mechanosensory cells of bone, and the lacuno-canalicular porosity as the structure that mediates mechanosensing. Strain-derived flow of interstitial fluid through this porosity seems to mechanically activate the osteocytes, as well as ensuring transport of cell signaling molecules and nutrients and waste products. This concept allows an explanation of local bone gain and loss, as well as remodeling in response to fatigue damage, as processes supervised by mechanosensitive osteocytes.—Burger, E. H., Klein-Nulend, J. Mechanotransduction in bone—role of the lacuno-canalicular network.