Paolo Taboga | California State University, Sacramento (original) (raw)

Papers by Paolo Taboga

bioRxiv (Cold Spring Harbor Laboratory), Dec 8, 2022

This study aims to validate the Fuze system (SwiftMotion, CA, USA), against the gold standard for... more This study aims to validate the Fuze system (SwiftMotion, CA, USA), against the gold standard for motion capture, a 3D infra-red motion capture system (Vicon Nexus, Oxford, UK). Fuze system uses inertial measurement units and proprietary algorithms to calculate position and orientation of each body segment Six subjects (3M and 3F) performed two activities that simulate common occupational physical activities. For both systems, we calculated the following joint angles: trunk relative to horizontal, left and right shoulder and hip joint angles. We also calculated the horizontal distance of each wrist relative to the the fifth lumbar vertebra. For each measurement, we calculated Bias (average difference between Fuze and Vicon system) and root mean squared error (RMSE). We also compared each measurement using a Statistical Parametric Mapping (SPM) method with a statistical significance level set at 0.05. Compared to Vicon, Fuze system had a maximum Bias of 5.63 ± 1.60 degrees for the left shoulder angle and a maximum RMSE of 10.03 ± 2.73 degrees for the left hip angle. SPM analysis evidenced that for all the measurements, comparisons were within the critical thresholds for significance for the whole duration of the trials, indicating that we could not find a significant difference between Vicon and Fuze measurements. In conclusion: the Fuze system compares well with the Vicon system and provides reliable data for the measurement of joint angles and body positions, that can be used in particular in non labbased settings, for example in ergonomics risk assessments. This study aims to validate the Fuze system against the gold standard for motion capture, a 3D infra-red motion capture system (Vicon Nexus, Oxford, UK). By comparing data collected by both systems, we can determine accuracy and reproducibility of the Fuze system, allowing researchers, occupational therapist, and investigators to select the most appropriate device for their future needs.

Journal of Biomechanics, 2006

Medicine and Science in Sports and Exercise, May 1, 2014

Gait & Posture, Dec 1, 2006

A lower limb model has been developed in which kinematic constraints of hip, knee, and ankle join... more A lower limb model has been developed in which kinematic constraints of hip, knee, and ankle joints are defined on the basis of functional anatomy and data collected from MRI and fluoroscopy. In particular the femoral-tibial motion was supposed to be constrained by the knee cruciate ligaments. The feasibility of the model was checked on a normal subject walking on level at natural cadence and performing on site exercises. Thirty-one reflective markers were positioned on pelvis and lower limbs: they were used to identify anatomical landmarks and allowed us to connect a 3-D model of bones to the collected data. Our results show that kinematics of femur in relation to pelvis and shank can be accurately obtained through identification of hip joint centre, shank location, and knee joint kinematic constraints. The markers located on the thigh (greater trochanter, medial and lateral femoral epicondyles), which were the most affected by skin motion artefacts, can be profitably removed from our protocol, and the advantage will be reduced encumbrance and improved accuracy.

Royal Society Open Science

Athletes with transtibial amputation (TTA) use running-specific prostheses (RSPs) to run. RSP con... more Athletes with transtibial amputation (TTA) use running-specific prostheses (RSPs) to run. RSP configuration likely affects the biomechanics of such athletes across speeds. We determined how the use of three RSP models (Catapult, Sprinter and Xtend) with three stiffness categories (recommended, ±1), and three heights (recommended, ±2 cm) affected contact length ( L c ), stance average vertical ground reaction force ( F avg ), step frequency ( f step ) and asymmetry between legs for 10 athletes with unilateral TTA at 3–7 m s −1 . The use of the Xtend versus Catapult RSP decreased L c ( p = 2.69 × 10 −7 ) and F avg asymmetry ( p = 0.032); the effect on L c asymmetry diminished with faster speeds ( p = 0.0020). The use of the Sprinter versus Catapult RSP decreased F avg asymmetry ( p = 7.00 × 10 −5 ); this effect was independent of speed ( p = 0.90). The use of a stiffer RSP decreased L c asymmetry ( p ≤ 0.00033); this effect was independent of speed ( p ≥ 0.071). The use of a shorter R...

Figure 1.8 Ground reaction forces (GRF) on a sprinter along a straight path (A) and on a curved p... more Figure 1.8 Ground reaction forces (GRF) on a sprinter along a straight path (A) and on a curved path (B).

Medicine & Science in Sports & Exercise, 2020

All runners experience physiological fatigue during a run. Research shows physiological stress in... more All runners experience physiological fatigue during a run. Research shows physiological stress induced by fatigue influences changes in running biomechanics. However, past studies have focused on a limited number of kinematic variables during fatigue. To understand the interrelationship between a plurality of kinematic variables, a study was conducted to observe changes in stride length (SL), ground contact time (GCT), foot strike angle (FSA), and cadence (CAD). It was hypothesized fatigue would yield a decreased CAD, increased GCT and SL, and shift subjects to a more rear-foot FSA. PURPOSE: To examine the influence of physiological fatigue on running biomechanics during a short bout of high-intensity running. METHODS: Male and female athletes of all levels (n=36; 15 female; 33 ± 9 years; 70.11 ± 13.66 kg; 171.37 ± 9.75 cm) participated in a 20-minute treadmill fatiguing protocol. Subjects first ran 5 minutes at their preferred pace (speed one), followed by ten minutes at a fatiguing pace (speed two), and ended with five minutes at speed one. Speed two was .67-.89 m/s faster than speed one, near estimated vVO2max. Kinematic time series data from a shoe embedded accelerometer was collected for the following metrics: CAD, SL, GCT, and FSA. The first 30 seconds of speed two (fatigue start) was analyzed and compared to the last 30 seconds of speed two (fatigue end). Subjects were considered fatigued when heart rate met or exceeded 90% age predicted max and RPE ≥ 17. Significant differences between fatigue start and fatigue end were tested with a varied samples t-test. RESULTS: Significant differences were identified between fatigue start and fatigue end for CAD (173.36+13.91 vs 169.92+11.99 steps/min, p<0.001), SL (2.45+0.34 vs 2.50+0.34 meters, p=0.003), and GCT (279.61+44.25 vs 285.25+44.44 ms, p=0.004). CAD decreased while SL and GCT increased. No significant difference was observed for FSA. CONCLUSION: This study demonstrated biomechanical changes in running form from the beginning to the end of a short, high-intensity fatiguing run. The direction of change for cadence, stride length, and ground contact time confirmed the hypothesis. Changes in foot strike angle were not confirmed.

We aimed to determine a method for prescribing a standing prosthetic leg length (ProsL) that resu... more We aimed to determine a method for prescribing a standing prosthetic leg length (ProsL) that results in an equivalent running biological leg length (BioL) for athletes with unilateral and bilateral transtibial amputations (UTTA and BTTA, respectively). We measured standing leg length of ten non-amputee (NA) athletes, ten athletes with UTTA, and five athletes with BTTA. All athletes performed treadmill running trials from 3 m/s to their maximum speed. We calculated standing and running BioL and ProsL lengths and assessed the running-to-standing leg length ratio (Lratio) at three instances during ground contact: touchdown, mid-stance, and take-off. Athletes with UTTA had 2.4 cm longer standing ProsL than BioL length (p = 0.030), but up to 3.3 cm and 4.1 cm shorter ProsL than BioL length at touchdown and mid-stance, respectively, at speed 3-11.5 m/s. At touchdown, mid-stance, and take-off, athletes with BTTA had 0.01–0.05 lower Lratio at 3 m/s (p < 0.001) and 0.03–0.07 lower Lratio ...

Treadmill ground reaction force data from the fastest athlete with bilateral leg amputations at 3... more Treadmill ground reaction force data from the fastest athlete with bilateral leg amputations at 3 to 11.4 m/s

Radar gun and starting block ground reaction force data from the fastest athlete with bilateral l... more Radar gun and starting block ground reaction force data from the fastest athlete with bilateral leg amputations during 0–20 m sprint trials

Aerobic metabolism data from the fastest athlete with bilateral leg amputations during submax and... more Aerobic metabolism data from the fastest athlete with bilateral leg amputations during submax and maximum aerobic running trials

Photo showing the end of a curve running trial from the fastest athlete with bilateral leg amputa... more Photo showing the end of a curve running trial from the fastest athlete with bilateral leg amputations

Royal Society Open Science, 2022

Running-prostheses have enabled exceptional athletes with bilateral leg amputations to surpass Ol... more Running-prostheses have enabled exceptional athletes with bilateral leg amputations to surpass Olympic 400 m athletics qualifying standards. Due to the world-class performances and relatively fast race finishes of these athletes, many people assume that running-prostheses provide users an unfair advantage over biologically legged competitors during long sprint races. These assumptions have led athletics governing bodies to prohibit the use of running-prostheses in sanctioned non-amputee (NA) competitions, such as at the Olympics. However, here we show that no athlete with bilateral leg amputations using running-prostheses, including the fastest such athlete, exhibits a single 400 m running performance metric that is better than those achieved by NA athletes. Specifically, the best experimentally measured maximum running velocity and sprint endurance profile of athletes with prosthetic legs are similar to, but not better than those of NA athletes. Further, the best experimentally mea...

Non-amputee runners increase leg stiffness (kleg) and decrease contact time (tc) to achieve faste... more Non-amputee runners increase leg stiffness (kleg) and decrease contact time (tc) to achieve faster running speeds [1, 2]. Kram and Taylor [3] suggest that longer tc reduces the rate of muscular force production, thereby facilitating the recruitment of slower more economical muscle fibers which decreases the energetic cost of running. Thus, it is likely that a lower kleg (and longer tc) reduces the metabolic cost of running.

Journal of Sports Sciences, 2020

Eliud Kipchoge made two attempts to break the 2-hour marathon, in Monza and then Vienna. Here we ... more Eliud Kipchoge made two attempts to break the 2-hour marathon, in Monza and then Vienna. Here we analyse only the effects of course elevation profile and turn curvatures on his performances. We used publicly available data to determine the undulations in elevation and the radii of the curves on the course. With previously developed equations for the effects of velocity, slope, and curvature on oxygen uptake, we performed simulations to quantify how much the elevation changes and curves of the Vienna course affect a runner's oxygen uptake (at a fixed velocity) or velocity (at a fixed oxygen uptake). We estimate that, after the initial downhill benefit, the course led to an overall oxygen uptake penalty of only 0.03%. When compared to a perfectly level straight course, we estimate that the combined effects of the undulations and curves of the Vienna course incurred a penalty of just 1.37 seconds. Kipchoge ran 2:00:25 in Monza Italy. Comparison with the Monza course profile indicates a 46.2 second (1.09% oxygen uptake) advantage of Vienna's course while the fewer curves of Vienna contributed ~ 1 second. The Vienna course was very well-chosen because it minimized the negative effects of elevation changes and curves. Abbreviations: CoT: Oxygen cost of transport; C _ VO 2 : Curved rate of oxygen consumption; _ VO 2 : Rate of oxygen consumption; WA: World Athletics ARTICLE HISTORY