Aliah F. Shaheen

Rigid and Elastic taping changes scapular kinematics and pain in subjects with shoulder impingement syndrome; an experimental study

Rigid and Elastic scapular taping is used in physical rehabilitation of shoulder impingement syndrome (SIS). It is believed to reduce pain and normalise scapular movement patterns. However, there is insufficient evidence to support its use. The aim of the study was to investigate the effect of Rigid and Elastic taping techniques on the scapular kinematics and pain in patients with SIS. Eleven patients with SIS participated in the study. They performed elevation and lowering of the arm in the scapular and sagittal planes under three conditions: Baseline, Rigid taping and Elastic taping. The movements of the thorax, humerus and scapula were tracked. Scapular displacements and scapulothoracic joint rotations were calculated. Subjects used a visual analogue scale to rate the intensity of pain at rest and during movements in both planes. Both taping techniques externally rotated the scapula in sagittal plane movements (p<0.05) and resulted in reduced pain. In the scapular plane, Elastic taping increased the scapular retraction (p<0.05) and posterior displacement (p<0.01), but neither of the taping techniques had an effect on pain in this plane. In conclusion, both taping techniques had an effect on scapular kinematics and pain in movements occurring in the sagittal plane. Elastic taping also affected scapular kinematics in scapular plane movements, but without the concomitant decrease in pain.

Evaluation of Methods Based on Conventional Videography for Detection of Gait Events

The detection of gait events plays an important role in gait analysis. The initial foot contact (IC) and the end of foot contact or foot off (FO) represent the start of stance and swing, respectively. They are commonly used to compute parameters that offer information for the characterization of gait.

Assessment of the glenohumeral joint's active and passive axial rotational range

BACKGROUND Assessment of the range of axial rotation of the glenohumeral joint will improve understanding of shoulder function, with applications in shoulder rehabilitation and sports medicine. However, there is currently no complete description of motion of the joint. The study aimed to develop a reliable protocol to quantify the internal and external axial rotations of the glenohumeral joint during active and passive motion at multiple humeral positions. METHODS Optical motion tracking was used to collect kinematic data from 20 healthy subjects. The humerus was positioned at 60°, 90°, and 120° of humerothoracic elevation in the coronal, scapular, and sagittal planes. Internal and external rotations were measured at each position for active and passive motion, where intrasubject standard deviations were used to assess variations in internal-external rotations. RESULTS The protocol showed intrasubject variability in the axial rotational range of <5° for active and passive rotations at all humeral positions. Maximum internal rotation was shown to be dependent on humeral position, where a reduced range was measured in the sagittal plane (P < .001) and at 120° elevations (P < .001). Conversely, maximum external rotations were not affected by humeral position. CONCLUSION The results describe normal ranges of internal-external rotation of the glenohumeral joint at multiple humeral positions. The protocols low variability means that it could be used to test whether shoulder pathologic conditions lead to changes in axial rotational range at specific humeral positions.

Effects of anterior compartment fasciotomy on intramuscular compartment pressure in patients with chronic exertional compartment syndrome

Background Patients with chronic exertional compartment syndrome (CECS) have pain during exercise that usually subsides at rest. Diagnosis is usually confirmed by measurement of intramuscular compartment pressure (IMCP) following exclusion of other possible causes. Management usually requires fasciotomy but reported outcomes vary widely. There is little evidence of the effectiveness of fasciotomy on IMCP. Testing is rarely repeated postoperatively and reported follow-up is poor. Improved diagnostic criteria based on preselection and IMCP levels during dynamic exercise testing have recently been reported. Objectives (1) To compare IMCP in three groups, one with classical symptoms and no treatment and the other with symptoms of CECS who have been treated with fasciotomy and an asymptomatic control group. (2) Establish if differences in IMCP in these groups as a result of fasciotomy relate to functional and symptomatic improvement. Methods Twenty subjects with symptoms of CECS of the anterior compartment, 20 asymptomatic controls and 20 patients who had undergone fasciotomy for CECS were compared. All other possible diagnoses were excluded using rigorous inclusion criteria and MRI. Dynamic IMCP was measured using an electronic catheter wire before, during and after participants exercised on a treadmill during a standardised 15 min exercise challenge. Statistical analysis included t-tests and analysis of variance. Results Fasciotomy results in reduced IMCP at all time points during a standardised exercise protocol compared with preoperative cases. In subjects responding to fasciotomy, there is a significant reduction in IMCP below that of preoperative groups (P<0.001). Postoperative responders to fasciotomy have no significant differences in IMCP from asymptomatic controls (P=0.182). Conclusion Fasciotomy reduces IMCP in all patients. Larger studies are required to confirm that the reduction in IMCP accounts for differences in functional outcomes and pain reductions seen in postoperative patients with CECS.

BAREFOOT PLANTAR PRESSURE MEASUREMENT IN CHRONIC EXERTIONAL COMPARTMENT SYNDROME

Patients with chronic exertional compartment syndrome (CECS) have pain during exercise that usually subsides at rest. Accompanying the pain, a change in gait is frequently described by patients. This typically manifests as a progressive loss of control of ankle movements, often described as ‘foot slap’. This study aimed to investigate the differences in plantar pressure between CECS cases and asymptomatic controls in a rested pre-symptomatic state. 20 men with symptoms of CECS of the anterior compartment and 20 asymptomatic controls participated. Barefoot plantar pressure was measured during walking and marching. Data was analysed to determine: stance time; foot progression angle; the mean of the medial-lateral displacement of centre of force; time from initial foot contact to initial full forefoot contact (IFFC-time); the medial-lateral distribution of pressure under the heel; and, the ratio between inner and outer metatarsal loading. Cases had shorter stance times and IFFC-times than controls. Foot progression angle was inversely related to walking speed. The area under the receiver operating curve for IFFC-time ranged from 0.746 −0.773 representing ‘fair predictive validity’. Cases have an increased rate of ankle plantarflexion after heel strike. It has recently been observed that there is almost no change in the length of the tibialis anterior muscle during the gait cycle with almost all of the changes in length of the muscle-tendon unit occurring within the tendon during walking. It follows that lowering of the foot after heel strike occurs through tendon stretch whilst the muscle contracts isometrically. Therefore if IFFC is reduced in CECS cases it is plausible that this is due to stretching of the tendon although inherent weakness in the muscle cannot be excluded. This is postulated to result from either Tibialis Anterior muscle weakness or elongation of the tendon. The observed biomechanical difference in cases may give further insight into the pathophysiology of this condition and enable further development of a non-invasive diagnostic modality. Diagnostically, the value of IFFC-time is comparable to post-exercise invasive diagnostic tests but falls short of that achieved with invasive testing during prolonged painful exercise.

Effects of lighting illuminance levels on stair negotiation performance in individuals with visual impairment

BACKGROUND Stair-related falls of older people cause a substantial financial and social burden. Deterioration of the visual system amongst other factors put older people at a high risk of falling. Improved lighting is often recommended. The aim of this study was to investigate the effect of lighting illuminance on stair negotiation performance in older individuals with visual impairment. METHODS Eleven participants aged 60 or over with a vision of 6/18 or worse ascended and descended a staircase under: 50 lx, 100 lx, 200 lx, 300 lx and distributed 200 lx lighting. A motion capture system was used to measure movements of the lower limb. Clearance, clearance variability, temporal and spatial parameters and joint/segment kinematics were computed. FINDINGS There was no effect on clearance or clearance variability. Participants had lower speed, cadence, increased cycle time and stance time in the 50 lx compared to 300 lx and distributed 200 lx lighting in descent. The minimum hip angle in ascent was increased in the 200 lx lighting. Clearance was found to be moderately correlated with balance scores. INTERPRETATION Individuals with visual impairment adopt precautionary gait in dim lighting conditions. This does not always result in improvements in the parameters associated with risk of falling (e.g. clearance).

Simulated activities of daily living do not replicate functional upper limb movement or reduce movement variability

Kinematic assessments of the upper limb during activities of daily living (ADLs) are used as an objective measure of upper limb function. The implementation of ADLs varies between studies; whilst some make use of props and define a functional target, others use simplified tasks to simulate the movements in ADLs. Simulated tasks have been used as an attempt to reduce the large movement variability associated with the upper limb. However, it is not known whether simulated tasks replicate the movements required to complete ADLs or reduce movement variability. The aim of this study is to evaluate the use of simulated tasks in upper limb assessments in comparison to functional movements. Therefore answering the following questions: Do simulated tasks replicate the movements required of the upper limb to perform functional activities? Do simulated tasks reduce intra- and inter-subject movement variability? Fourteen participants were asked to perform five functional tasks (eat, wash, retrieve from shelf, comb and perineal care) using two approaches: a functional and a simulated approach. Joint rotations were measured using an optoelectronic system. Differences in movement and movement variability between functional and simulated tasks were evaluated for the thorax, shoulder, elbow/forearm and wrist rotations. Simulated tasks did not accurately replicate the movements required for ADLs and there were minimal differences in movement variability between the two approaches. The study recommends the use of functional tasks with props for future assessments of the upper limb.

Investigation of fullerenol-induced changes in poroelasticity of human hepatocellular carcinoma by AFM-based creep tests

In this study, atomic force microscopy (AFM) is used to investigate the alterations of the poroelastic properties of hepatocellular carcinoma (SMMC-7721) cells treated with fullerenol. The SMMC-7721 cells were subject to AFM-based creep tests, and a corresponding poroelastic indentation model was used to determine the poroelastic parameters by curve fitting. Comparative analyses indicated that the both permeability and diffusion of fullerenol-treated cells increased significantly while their elastic modulus decreased by a small amount. From the change in the trend of the determined parameter, we verified the corresponding alternations of cytoskeleton (mainly filaments actin), which was reported by the previous study using confocal imaging method. Our investigation on SMMC-7721 cell reveals that the poroelastic properties could provide a better understanding how the cancer cells are affected by fullerenol or potentially other drugs which could find possible applications in drug efficacy test, cancer diagnosis and secure therapies.

Shoulder Bone Geometry Affects the Active and Passive Axial Rotational Range of the Glenohumeral Joint

Background: The range of motion of the glenohumeral joint varies substantially among individuals and is dependent on humeral position. How variation in shape of the humerus and scapula affects shoulder axial range of motion at various positions has not been established. Purpose: To quantify variation in the shape of the glenohumeral joint and investigate whether the scapula and humerus geometries affect the axial rotational range of the glenohumeral joint. Study Design: Descriptive laboratory study. Methods: The range of active and passive internal-external rotation of the glenohumeral joint was quantified for 10 asymptomatic participants with optical motion tracking at 60º, 90º, and 120º humeral elevations in the coronal, scapular, and sagittal planes. Bone geometrical parameters were acquired from shoulder magnetic resonance image scans, and correlations between geometrical parameters and maximum internal and external rotations were investigated. Three-dimensional participant-specific models of the humerus and scapula were used to identify collisions between bones at the end of range. Results: Maximum internal and external rotations of the glenohumeral joint were correlated to geometric parameters and were limited by bony collisions. Generally, the active axial rotational range was greater with increased articular cartilage and glenoid curvature, while a shorter acromion resulted in greater passive range. Greater internal rotation was correlated with a greater glenoid depth and curvature in the scapular plane (r = 0.76, P < .01, at 60° of elevation), a greater subacromial depth in the coronal plane (r = 0.74, P < .01, at 90° of elevation), and a greater articular cartilage curvature in the sagittal plane (r = 0.75, P < .01, at 90° of elevation). At higher humeral elevations, a greater subacromial depth and shorter acromion allowed a greater range of motion. Conclusion: The study strongly suggests that specific bony constraints restrict the maximum internal and external rotations achieved in active and passive glenohumeral movement. Clinical Relevance: This study identifies bony constraints that limit the range of motion of the glenohumeral joint. This information can be used to predict full range of motion and set patient-specific rehabilitation targets for those recovering from shoulder disorders. It can improve positioning and choice of shoulder implants during preoperative planning by considering points of collision that could limit range of motion.

Evaluation of a visual method to calculate temporal parameters

Analysis of human movement provides systematic and quantitative information of movement. A number of tools and methods have been proposed to detect events that occur during walking. The events are then used to calculate spatiotemporal parameters (STP), commonly used for the characterization of gait. Conventional video cameras were proposed as an alternative for gait event detection. However, the accuracy in the calculation of STP has not been evaluated yet. The aim of this study is to evaluate the accuracy of a fully visual method using these cameras in the calculation of STP.