Papers by Moataz Eltoukhy
Gait & Posture, Oct 1, 2017
Assessments using dynamic postural control tests, like the Star Excursion Balance Test (SEBT), in... more Assessments using dynamic postural control tests, like the Star Excursion Balance Test (SEBT), in combination with three-dimensional (3D) motion analysis can yield critical information regarding a subject's lower limb movement patterns. 3D analysis can provide a clear understanding of the mechanisms that lead to specific outcome measures on the SEBT. Currently, the only technology for 3D motion analysis during such tests is expensive marker-based motion analysis systems, which are impractical for use in clinical settings. In this study we validated the use of the Microsoft Kinect as a cost-effective and marker-less alternative to more complex and expensive gold-standard motion analysis systems. Ten healthy subjects performed the SEBT while their lower limb kinematics were measured concurrently using a traditional motion capture system and a single Kinect v2 sensor. Analyses revealed errors in lower limb kinematics of less than 5°, except for the knee frontal-plane angle (5.7°) in the posterior-lateral direction. Ensemble curve analyses supported these findings, showing minimal between-system differences in all directions. Additionally, we found that the Kinect displayed excellent agreement (ICC 3,k = 0.99) and consistency (ICC 2,k = 0.99) when assessing reach distances in all directions. These results indicate that this low-cost and easy to implement technology may provide to clinicians a simple tool to simultaneously assess reach distances while developing a clearer understanding of the lower extremity movement patterns associated with SEBT performance in healthy and injured populations.
Medical Engineering & Physics, Dec 1, 2017
Kinetic gait abnormalities result in reduced mobility among individuals with Parkinson's disease ... more Kinetic gait abnormalities result in reduced mobility among individuals with Parkinson's disease (PD). Currently, the assessment of gait kinetics can only be achieved using costly force plates, which makes it difficult to implement in most clinical settings. The Microsoft Kinect v2 has been shown to be a feasible clinic-based alternative to more sophisticated three-dimensional motion analysis systems in producing acceptable spatiotemporal and kinematic gait parameters. In this study, we aimed to validate a Kinectdriven musculoskeletal model using the AnyBody modeling system to predict three-dimensional ground reaction forces (GRFs) during gait in patients with PD. Nine patients with PD performed over-ground walking trials as their kinematics and ground reaction forces were measured using a Kinect v2 and force plates, respectively. Kinect v2 model-based and force-plate measured peak vertical and horizontal ground reaction forces and impulses produced during the braking and propulsive phases of the gait cycle were compared. Additionally, comparison of ensemble curves and associated 90% confidence intervals (CI90) of the three-dimensional GRFs were constructed to investigate if the Kinect sensor could provide consistent and accurate GRF predictions throughout the gait cycle. Results showed that the Kinect v2 sensor has the potential to be an effective clinical assessment tool for predicting GRFs produced during gait for patients with PD. However, the observed findings should be replicated and model reliability established prior to integration into the clinical setting.
Sports and exercise medicine, Jul 20, 2015
Treadmills allow for collecting multiple steps in a small area, and continuous testing for a long... more Treadmills allow for collecting multiple steps in a small area, and continuous testing for a long period of time with multiple speeds. These factors prove to be useful for biomechanics research laboratories that are usually equipped with floor embedded platforms. Acquiring instrumented treadmills with a built in force plate(s)-may not be financially feasible for many general purpose biomechanics laboratories; additionally instrumented treadmills only measures the vertical component of ground reaction force. The purpose of this study was to examine the components of Ground Reaction Force (GRF) in treadmill walking which were measured by placing a treadmill over floor-mounted force plates and to develop a set of regression equations to be used in associating treadmill's GRF components with GRF components obtained during overground walking. The GRF measured during the treadmill walk was compared to GRF measured in overground walking. A total of twelve male subjects participated in this study. The analysis of the data did not reveal statistical differences in the anterior-posterior component of the GRF (APGRFP1 and APGRFP2) and in the early-stance and mid-stance peaks of the vertical GRF (VGRFP1 and VGRFP2) between treadmill and overground walking. Statistical differences between treadmill and overground walking were found during latestance for vertical ground reaction force (VGRFP3) and medial lateral ground reaction force (MLGRFP2) (p<0.05). During push-off-occurring in late-stance-vertical ground reaction force peaks (VGRFP3) were less in treadmill walking than in overground walking by 5-6% (p<0.05). The Medial-lateral ground reaction forces peaks (MLGRFP2) were also less in treadmill walking than in overground walking by 1-2% (p<0.05). In addition, five regression equations were developed for treadmill's GRF.
Sports and exercise medicine, Aug 3, 2015
InTech eBooks, Nov 25, 2011
International Journal of Industrial Ergonomics, Sep 1, 2018
Manual material handling (MMH) contributes to a large percentage of musculoskeletal disorders. On... more Manual material handling (MMH) contributes to a large percentage of musculoskeletal disorders. One of its fundamental activities is load carrying that can be accomplished in several strategies, with each one imposing different types of stresses on the musculoskeletal system. Therefore, the first goal of this study was to determine the effect of different carrying methods on walking stability using motion capture analysis. Second, to analyze gait adaptations to stresses associated with load carrying in order to prevent falling. Third, to investigate the effect of these stresses coupled with human body adjustment on the forces at the L5/S1 disc. Thirty participants carried 10 and 30 lbs loads via frontal, lateral, bilateral, and posterior carriages. Frontal and lateral methods generated the most unstable conditions compared to the others. The unstable locomotion forced the gait parameters to be significantly altered in order to maintain stability. Additionally, the postures maintained in these conditions resulted in significantly high compression and shear forces acting at the L5/S1 disc when compared to the other carrying methods. Moreover, heavier weights exacerbated the effect on the dependent variables. Notably, bilateral and posterior carrying methods provided results comparable to the unloaded walking baseline. In conclusion, to reduce the potential risks associated with load carrying, the recommendation to split the load between both hands using bilateral carrying method or carrying it posteriorly should be taken into account while designing MMH activities. Relevance to Industry: Injuries due to falls in the workplace are common issues among many workers. A major factor to these incidents is load carrying that can be accomplished with different postures. The human body adopts different compensation strategies in terms of gait patterns, and trunk adjustments. Those types of adaptive strategies may compromise dynamic stability, potentially leading to falls, and stresses on the spine. Investigating the effects of different carrying methods examined in this study can be used in designing manual material carrying tasks in order to reduce the potential risk associated with load carrying.
AERA Online Paper Repository, Apr 13, 2018
Journal of Science and Medicine in Sport, 2017
Patients commonly experience altered response to fatiguing exercise after ACL reconstruction (ACL... more Patients commonly experience altered response to fatiguing exercise after ACL reconstruction (ACLR). The objective of this study was to assess the impact of quadriceps strengthening on response to exercise after ACLR. Clinical trial. Ten participants with a history of primary, unilateral ACLR (sex=9F/1M, age=21.0±2.8 years, BMI=23.7±2.7kg/m(2)) and 10 healthy participants (sex=9F/1M, age=22.2±3.2 years, BMI=23.8±3.9kg/m(2)) participated. ACLR participants completed a 2-week quadriceps strengthening intervention including 14 progressive strengthening exercise sessions. Normalized knee extension maximum voluntary isometric contraction (MVIC) torque (Nm/kg) and quadriceps central activation ratio (%, CAR) were measured before and after a 30-minute fatiguing exercise protocol. ACLR participants completed testing before and after the 2-week intervention while control participants completed a single testing session. The intervention significantly improved normalized knee extension MVIC torque (pre-intervention=1.85±0.67Nm/kg, post-intervention=2.09±0.81Nm/kg, p=0.04) and quadriceps CAR in the ACLR involved limb (pre-intervention=86.51±5.03%, post-intervention=92.94±5.99%, p=0.02). Quadriceps CAR (pre-intervention=1.13±9.04%, post-intervention=-3.97±4.59%, p=0.16) and normalized knee extension MVIC torque (pre-intervention=0.26±20.90%, post-intervention=-8.02±12.82%, p=0.30) response to exercise did not significantly change from pre-intervention to post-intervention conditions. Two weeks of quadriceps strengthening reduced this between group difference in the involved limb which may indicate restoration of more optimal quadriceps neuromuscular function and increased demand on the quadriceps during physical activity.
Journal for STEM Education Research, Nov 6, 2018
Although researchers have proposed different definitions for Computational Thinking (CT), one com... more Although researchers have proposed different definitions for Computational Thinking (CT), one commonality across these definitions is the emphasis on having students formulate and solve problems in various learning environments, including programming. The continuing attention to CT highlights the need for studies that examine students', especially elementary students, problem-solving processes. The current study investigates how fifth graders engaged in CT problem-solving activities in a programming environment. Focusing on multiple representations embedded in the CT problemsolving processes, we analyze data of fifth graders who were engaged in a pairprogramming robotics interview. In the interview, students navigate multiple representations, such as task instructions, a coding window, and outputs, and in the case of robotics programming activities, a physical robot. The results show that as students were participating in a variety of coding and problem-solving practices, they were interpreting and navigating information within the code window, across the code window and task instructions, across the code window and physical robot, and across all three representations. Informed by these findings, we propose a framework to conceptualize how elementary students interpret and navigate multiple representations in CT problem-solving processes, which could guide future studies in analyzing problem-solving processes in similar contexts. Implications on the importance of multiple representations in programming may apply to other CT learning environments as well. Keywords Computational thinking. Robotics education. Representations There has been a growing interest in computational thinking (CT) as a foundational twenty-first century skill that students should be learning in K-12 settings. As an
Journal of Applied Biomechanics, Feb 1, 2019
Anterior cruciate ligament (ACL) injury is one of the most common knee injuries among adolescent ... more Anterior cruciate ligament (ACL) injury is one of the most common knee injuries among adolescent athletes. Majority of the ACL injuries occur due to pivoting, sudden deceleration, and direction change without contact with any player. Preventive interventions can reduce risks of the ACL injury, thus developing a clinician friendly biomechanical assessment tool to identify athletes with such risk factors is crucial. In this study, the authors investigated the concurrent validity of a commercially available depth sensor, Microsoft Kinect, as a cost-effective alternative to the gold-standard 3-dimensional motion analysis systems in noncontact ACL screening for adolescent athletes during side-cut maneuvers. Study participants performed 45° side-cut maneuvers while collecting data from both systems concurrently. The sagittal and frontal plane kinematics were analyzed during the full stance phase and the first 20% of the stance (early deceleration). Absolute agreement (range: ICC = .767-.989) and consistency (range: ICC = .799-.992) were excellent for all measures except early deceleration frontal plane hip angle, which displayed good absolute agreement (ICC = .643) and consistency (ICC = .625). Findings showed that the Kinect has the potential to be an effective clinical assessment tool for sagittal and frontal plane trunk, hip, and knee kinematics during the side-cut maneuvers.
Gait & Posture, Feb 1, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Medical Engineering & Physics, Oct 1, 2018
Stair negotiation is one of the most challenging, yet frequently encountered, locomotor tasks in ... more Stair negotiation is one of the most challenging, yet frequently encountered, locomotor tasks in daily life. This study is the first attempt to investigate the capacity of the Kinect TM sensor to assess stair negotiation spatiotemporal and sagittal plane kinematic variables. The goal of this study was to examine the validity of the Kinect TM v2 sensor in assessing lower extremity kinematics and spatiotemporal parameters in healthy young individuals; and to demonstrate its potential as a low-cost stair gait analysis tool. Twelve healthy participants ascended and descended a 3-step custom-built staircase at their preferred speed, as spatiotemporal parameters and kinematics were extracted simultaneously using the Kinect TM and a threedimensional motion analysis. Spatiotemporal measures included gait speed, swing phase time, and double stance time. Kinematic outcomes included hip, knee, and ankle joint angles in the sagittal plane. Consistency (ICC 2,1) and absolute agreement (ICC 3,1) between the two systems were assessed using separate interclass correlations coefficients. In addition, ensemble curves and associated 90% confidence intervals (CI90) were generated for the hip, knee, and ankle kinematics to enable between system comparisons throughout the gait cycle. Results showed that the Kinect TM has the potential to be an effective clinical assessment device for sagittal plane hip and knee joint kinematics and for some spatiotemporal parameters during the stair gait negotiation.
Medicine and Science in Sports and Exercise, May 1, 2014
Journal of Strength and Conditioning Research, Sep 1, 2018
The benefits of muscular power on sport performance and older adults' abilities to live independe... more The benefits of muscular power on sport performance and older adults' abilities to live independently and resist falls is well documented. Consequently, a substantial volume of research has focused on establishing the optimal loading patterns for improving muscular power using resistance exercise; however, to date, this research has only targeted optimal loading during training with free weights or selectorized exercise machines. Conversely, no approach has been developed to establish optimal loads for elastic modalities, such as tubes and bands, commonly used for sports rehabilitation, injury prevention, and training older adults. Therefore, the purpose of this study was to evaluate a new method for determining the optimal tubes to use in power training performed with elastic resistance. Thirty-eight recreationally active college students (age, 23.7 6 4.5 years) were recruited to perform 3 single-arm bicep curls at a maximum intended velocity using 6 elastic tubes of varying resistance. Testing was performed in a 3-dimensional (3D) motion analysis laboratory using a specially constructed platform with an integrated strain gauge to which each tube was anchored. Force data from the strain gauge and velocity data from the 3D motion capture system were then used to compute power for each tube. An analysis based on individual's cable arm curl 1-repetition maximum (1RM) was then used to generate general guidelines for the most appropriate tube to use for arm curl power training based on upper arm 1RM. Our results demonstrate the feasibility of using this methodology for other exercises, thereby establishing optimal tube use for power training based on each exercise's 1RM.
Journal of research on technology in education, Nov 30, 2020
Computational thinking (CT) has been advocated as an essential problem solving skill students nee... more Computational thinking (CT) has been advocated as an essential problem solving skill students need to develop. Emphasizing on CT applied in both programming and everyday contexts, we developed a humanoid robotics curriculum and a computerized assessment instrument. We implemented the curriculum with six classes of 125 fifth graders. Quantitative methods were used to compare students' performance from pretest to posttest. Learning analytics techniques were applied to examine students' problem solving processes. The results showed that students' CT performance improved in both programming and everyday reasoning contexts and that the curriculum benefited students with varied initial performance. The study shed light on how to connect and assess CT in everyday reasoning and programming contexts.
Medicine and Science in Sports and Exercise, May 1, 2016
Dissertation supervised by Professor Joseph F. Signorile. No. of pages in text. (68) Background a... more Dissertation supervised by Professor Joseph F. Signorile. No. of pages in text. (68) Background and Purpose: Human locomotion requires characteristic muscle activation timing patterns that work in a defined fashion along a kinetic chain. Sling systems are chains of muscles and innervating fascia that facilitate sequential muscle activation patterns during movement. The purpose of this study was to examine four sling systems across a running gait cycle and to determine how they might differ between runners with high and low running economy. Participants: Twenty-five recreational runners (11M, 14F, height = 1.73 ± .07 m, mass = 70.3 ± 11.7 kg, age = 28.6 ± 5.1 years) completed this study. Methods: Recreational runners completed a running economy test and were classified as high economy or low economy based on published normative data. On a separate testing day, runners completed overground running trials at a 10-km race pace and slow running pace. Surface electromyography was used to measure muscle activation during run trials for four sling systems: the Posterior Oblique Sling (POS: gluteus maximus and contralateral latissimus dorsi), the Anterior Oblique Sling (AOS: external oblique and contralateral adductors), the Lateral Sling (LAT: gluteus medius, tensor fascia latae (TFL), and contralateral quadratus lumborum (QL)), and the Deep Longitudinal Sling (LONG: tibialis anterior (TA), peroneus longus, biceps femoris (BF), multifidus, and erector spinae (ES)). Mixed-Design ANOVAs were conducted to determine differences among sling systems and between groups in muscle onset time (EMG onset), muscle offset time (EMG offset), peak amplitude (EMG amp), and time of peak amplitude (EMG peak). Peak times and amplitudes for the muscles of the AOS could not be established as these muscles displayed nearly constant activation throughout the gait cycle. Results: Significant main effects were observed in the POS, LONG, and LAT at both the 10-km race pace and slow running pace for EMG onset, EMG offset , EMG peak , and EMG amp. Differences between high economy and low economy runners were observed for ES EMG onset Burst 3, ES EMG peak Burst 3, ES EMG amp Burst 3,BF EMG onset Burst 1, BF EMG peak Burst 1, BF EMG offset Burst 2, BF EMG peak Burst 2, BF EMG peak Burst 3, BF EMG amp Burst 1, and TA EMG peak at the slow running speed. At the 10-km race pace, differences between high economy and low economy runners were observed for TFL EMG onset Burst 2, QL EMG offset Burst 1, QL EMG peak Burst 2, and QL EMG onset Burst 3. Discussion and Conclusion: Muscles in the POS, LAT, and LONG work in defined sequential and synchronous patterns across the gait cycle with significant variability between high economy and low economy runners.
Medicine and Science in Sports and Exercise, May 1, 2018
Uploads
Papers by Moataz Eltoukhy