Applied Bionics and Biomechanics - Volume 11, issue 3

Authors: Pacilli, Alessandra | Germanotta, Marco | Rossi, Stefano | Cappa, Paolo

Article Type: Research Article

Abstract: BACKGROUND: Although robotic therapy is at the forefront of upper limb rehabilitation, there is limited information about the importance of selecting age-matched subjects to evaluate recovery of arm movement during rehabilitation. OBJECTIVE: This study aims to quantify differences in the arm motion of healthy children and adults when they interact with a planar robot, in order to determine whether an age-matched control group is necessary in clinical studies involving pediatric patients. METHODS: Ten children (aged 7 to 10 years) and ten adults (aged 23 to 25 years) performed, at self-selected speed and accuracy, planar-reaching and circle-drawing movements with a robotic …device. We analyzed the motor performances for the two groups quantifying the participants' dexterity in completing two chosen tasks. The measurement of the entire upper limb was obtained by merging the data provided by the robot with that of an optical tracking system. RESULTS: Children drew circles with less smoothness than adults but with the same accuracy and joint coordination. During planar reaching task, children optimized only the coordination but performed the movement with less accuracy and smoothness than adults. CONCLUSIONS: Our findings provide evidence that age-matched healthy children should be used to quantify the recovery of robot-mediated therapy in children with upper limb impairments. Show more

Keywords: Age-related differences, smoothness, upper limb motor control, robot-mediated therapy, reaching, tracking

DOI: 10.3233/ABB-140095

Citation: Applied Bionics and Biomechanics, vol. 11, no. 3, pp. 91-104, 2014

Authors: Asraf Ali, Md. | Sundaraj, Kenneth | Badlishah Ahmad, R. | Ahamed, Nizam Uddin | Anamul Islam, Md.

Article Type: Research Article

Abstract: OBJECTIVE: To observe and analyse the literature on the use of surface electromyography electrodes, including the shape, size, and metal composition of the electrodes used, the interelectrode distance, and the anatomical locations on the muscle at which the electrodes are placed, for the observation of the triceps brachii muscle activity in patients and athletes. METHODS: We searched the ScienceDirect and SpringerLink online databases for articles published in the English language during the last six years (between January 2008 and December 2013). We specifically searched for the keywords “EMG” and “triceps brachii” in the full text of each of the articles. …The inclusion criteria were articles on the use of surface electromyography electrodes to observe the activity of the triceps brachii muscle in patients and athletes. RESULTS: In the 23 selected articles, the activities of the triceps brachii muscle in a total of 402 subjects were measured using surface electromyography electrodes: 262 subjects in the studies that focused on the rehabilitation of patients with various disorders, and 140 subjects in the studies that focused on the sports performance of various athletes. To record the surface electromyography activity of the triceps brachii muscle, the electrodes were placed over the muscle belly or the three heads (lateral, long, and medial) of the triceps brachii muscle with diverse interelectrode distances. Seventeen studies used bipolar or triode silver/silver chloride electrodes, one study utilised bipolar gold electrodes, one study applied bipolar polycarbonate electrodes, one study used a linear array of four silver bar electrodes, one study utilised DELSYS parallel bar nickel silver electrodes, and two studies did not clearly mention the composition of the electrodes used. CONCLUSIONS: Bipolar silver/silver chloride circular-shaped electrodes are utilised more frequently than electrodes with a different metal composition and shape. The anatomical locations of the triceps brachii muscle that mainly considered for electrode placement are the lateral, long, and medial heads. A 10-mm electrode size is commonly used to measure the sEMG activity more efficiently. However, we found that an electrode size of up to 40 mm may be used to reliably measure the sEMG activity on the triceps brachii muscle. A 20-mm interelectrode distance is commonly used to measure the sEMG activity using the above mentioned muscle locations and silver/silver chloride electrodes. We also identified others factors that should be taken into account for the use of the sEMG recording technique on the triceps brachii under real-time conditions. Show more

Keywords: Surface electromyography electrodes, triceps brachii muscle activity, rehabilitation; sports

DOI: 10.3233/ABB-140098

Citation: Applied Bionics and Biomechanics, vol. 11, no. 3, pp. 105-118, 2014

Authors: Yu, Seungnam | Han, Changsoo | Cho, Ilje

Article Type: Research Article

Abstract: This paper describes the development of a wearable exoskeleton system for the lower extremities of infantry soldiers and proposes appropriate design criteria based on existing case studies. Because infantry soldiers carry a variety of equipment, the interference with existing equipment and additional burden of the exoskeleton support system should be minimized. Recent studies have shown that a user only needs to be supported in the gravitational direction when walking on flat terrain; however, active joints are necessary to support walking over rough and sloped terrain such as mountains. Thus, an underactuated exoskeleton system was considered: passive joints are applied to …the hip and ankle joints, and active joints are applied to the knee joints to exploit the dynamic coupling effect of the link structure and muscular activation patterns when the user is going up and down stairs. A prototype of the exoskeleton system was developed and validated through a simple stair-climbing experiment. Show more

Keywords: Exoskeleton, wearable robot, infantry soldier, underactuated system, weight suppot mechanism (WSM)

DOI: 10.3233/ABB-140099

Citation: Applied Bionics and Biomechanics, vol. 11, no. 3, pp. 119-134, 2014

Authors: Sahli, Abderahmen | Benbarek, Smail | Wayne, Steven | Bachir Bouiadjra, Bel-Abbes | Serier, Boualem

Article Type: Research Article

Abstract: The total hip replacement is an operation that replaces a diseased hip with a mechanical articulation. Both components of the mechanical articulation (stem and the cup) are bonded to bone using orthopedic cement, whose reliability determines the longevity of the implant. The cement around the metallic stem forms a mantle whose strength and toughness determine its resistance to fatigue and failure by fracture. Typical cements are acrylic polymers that often suffer from internal cracks and other defects created during polymerization. This study is a systematic analysis of preexisting 3D crack behavior in the orthopedic cement mantle when subjected to external …body forces. Different crack orientations and angular positions around the mantle are studied to identify which locations will propagate the crack. This is accomplished by a global stress analysis of the mantle followed by a failure analysis. Amongst others, the existence of a crack in the proximal region of the orthopedic cement is identified as a critical area, especially in the lateral sides of the stem in the radial direction. Show more

Keywords: Bone cement, crack, 3D Finite element analysis, total hip prosthesis, stress intensity factor, LEFM

DOI: 10.3233/ABB-140097

Citation: Applied Bionics and Biomechanics, vol. 11, no. 3, pp. 135-147, 2014

Authors: Demir, Teyfik

Article Type: Research Article

Abstract: BACKGROUND: The use of pedicle screws is becoming increasingly popular for spinal surgery practice as the technology advances. Screw pullout due to bone quality and loading conditions is one of the most common problems observed after pedicle screw fixation. Several solutions were studied to prevent screw pullout. These can be investigated under three main categories: screw design, expandable screws and cement augmentation. OBJECTIVE: This study aimed to investigate the pullout performance of cannulated screws without cement augmentation on synthetic foams. METHODS: Artificial fusion process for PU is described and validated in our previous studies. For this study six newly designed …cannulated pedicle screws were artificially fused to PU foam and pullout test were conducted according to ASTM F543 standard testing protocols. RESULTS: According to the results of post-fusion pullout tests, worst performed cannulated screw design was S3H on healthy bone simulating PU foam. However, pullout strength of unilaterally three holes including (S3H) design was purchased with two times higher loads when compared to control group. Solid cored screws were purchased with 671 N where this value was 1450 N for S3H design. CONCLUSIONS: This study provided that using cannulated pedicle screws without cement augmentation for the cases with healthy bone can be a reliable alternative to classical screws. To the knowledge of the authors this is the first post-fusion study investigating cannulated pedicle screws without cement augmentation. Show more

Keywords: Cannulated pedicle screw, pullout, cement augmentation, post-fusion

DOI: 10.3233/ABB-140096

Citation: Applied Bionics and Biomechanics, vol. 11, no. 3, pp. 149-155, 2014

Authors: Hayat, T. | Yasmin, Humaira | Alsaedi, A.

Article Type: Research Article

Abstract: We investigate the peristaltic motion of Carreau fluid in an asymmetric channel with convective boundary conditions. Mathematical formulation is first reduced in a wave frame of reference and then solutions are constructed by long wavelength and low Reynolds number conventions. Results of the stream function, axial pressure gradient, temperature and pressure rise over a wavelength are obtained for small Weissenberg number. Velocity and temperature distributions are analyzed for different parameters of interest. A comparative study between the results of Newtonian and Carreau fluids is given.

Keywords: Asymmetric channel, Carreau fluid and convective conditions

DOI: 10.3233/ABB-140094

Citation: Applied Bionics and Biomechanics, vol. 11, no. 3, pp. 157-168, 2014