Biomechanical Outcomes Due to Impact Loading in Runners While Looking Sideways

2018 ◽  
Vol 34 (6) ◽  
pp. 483-487 ◽  
Author(s):  
Anamaria Laudet Silva Mangubat ◽  
Janet Hanwen Zhang ◽  
Zoe Yau-Shan Chan ◽  
Aislinn Joan MacPhail ◽  
Ivan Pui-Hung Au ◽  
...  
Keyword(s):  
Contact Time ◽  
Stride Length ◽  
Primary Outcome ◽  
Loading Rate ◽  
Random Sequence ◽  
Adaptive Strategies ◽  
Vertical Loading ◽  
Stride Rate ◽  
Head Stability ◽  
Running Head

A stable gaze is necessary to optimize visual conditions during running. Head accelerations generally remain stable when looking in front; however, it is unclear if this response is similar when the head is turned sideways, and whether other adaptive strategies are present to maintain this stability. The purpose of this study, therefore, was to examine whether runners maintained stable head accelerations while gazing at fixed targets in front and to their sides. The authors collected biomechanical data from 13 runners as they directed their gaze to visual targets located in front, 45°, and 90° to the sides at a random sequence. Vertical head and tibial accelerations were the primary outcome measures, while vertical loading rate, footstrike angle, contact time, stride length, and stride rate were the secondary measures. A reduction in vertical head accelerations was found in the rightmost direction (P = .04), while an increase in vertical tibial accelerations was found on the same direction (P = .02). No other significant differences were observed for the other variables. The results of this study suggest that the tibia accommodated the increased shock to maintain head stability.

scholarly journals Diagnosis of Orthostatic Tremor Using Smartphone Accelerometry Running Head: Smartphone Accelerometry for Orthostatic Tremor

2021 ◽  
Author(s):  
Nicholas E. Calvo ◽  
Joseph M. Ferrara
Keyword(s):  
Movement Disorder ◽  
Surface Electromyography ◽  
Primary Outcome ◽  
Fear Of Falling ◽  
Functional Movement ◽  
Orthostatic Tremor ◽  
Neurology Clinic ◽  
Low Amplitude ◽  
Running Head ◽  
Larger Sample

Abstract Background: Primary orthostatic tremor (OT) is a rare movement disorder characterized by a 13-18 Hz leg tremor, which arises when standing and is relieved by walking/sitting. Those affected generally do not fall, but experience fear of falling, lessened by ambulation. Because of its low amplitude, the tremor is not readily visible, and diagnosis requires confirmation with surface electromyography. Recently, applications using the accelerometer feature of smartphones have been used to detect and quantify tremors, including OT, though the accuracy of smartphone accelerometry in diagnosing OT is unknown. Methods: We completed SPA in consecutive adults (18+ years), who presented to our neurology clinic with either subjective leg shakiness upon standing or unsteadiness when standing that lessened with ambulation. We assessed tremor using the StudyMyTremor application on an iPhone 6s adhered with tape to the patient’s tibialis anterior. Surface electromyography was completed on the same muscle. The primary outcome of this study was to determine SPA’s sensitivity and specificity in detecting OT compared with surface electromyography. Results: Fifty-nine patients with the following diagnoses were included: OT (6), Parkinson’s disease, Hereditary Spastic Paraplegia, orthostatic hypotension, essential tremor, spinal cerebellar ataxia, sensory ataxia and functional movement disorder. Smartphone accelerometry detected a 13-18 Hz tremor in 5 of 6 patients diagnosed with OT by surface electromyography with no false positives in other conditions, yielding a sensitivity of 83%, specificity of 100% in the cohort we studied. Conclusions: Though a larger sample size is desirable, preliminary data suggest that smartphone accelerometry is an alternative to surface electromyography in diagnosing OT.

scholarly journals Non-Linear Relationship between Footstrike Angle and Vertical Loading Rate during Running

2019 ◽  
Vol 51 (Supplement) ◽  
pp. 185
Author(s):  
Mikel R. Stiffler-Joachim ◽  
Christa M. Wille ◽  
Bryan C. Heiderscheit
Keyword(s):  
Linear Relationship ◽  
Loading Rate ◽  
Vertical Loading ◽  
Non Linear

scholarly journals Running quietly reduces ground reaction force and vertical loading rate and alters foot strike technique

2016 ◽  
pp. 1-7 ◽  
Author(s):  
Xuan Phan ◽  
Tiffany L. Grisbrook ◽  
Kevin Wernli ◽  
Sarah M. Stearne ◽  
Paul Davey ◽  
...  
Keyword(s):  
Ground Reaction Force ◽  
Loading Rate ◽  
Reaction Force ◽  
Vertical Loading ◽  
Foot Strike

Hydrodynamic characterization in dissolved air flotation (DAF) contact zone

1998 ◽  
Vol 38 (6) ◽  
pp. 245-252 ◽  
Author(s):  
Ayman R. Shawwa ◽  
Daniel W. Smith
Keyword(s):  
Contact Zone ◽  
Peclet Number ◽  
Contact Time ◽  
Loading Rate ◽  
Dispersion Model ◽  
Dissolved Air Flotation ◽  
Péclet Number ◽  
Hydraulic Loading Rate ◽  
Hydraulic Loading ◽  
Recycle Ratio

The mechanism of bubble-floc interaction in a DAF contact zone is poorly understood and is usually described by conceptual models. This mechanism is highly dependent on the hydrodynamic conditions within the contact zone, i.e. contact time and degree of mixing. A pulse stimulus-response test was used to characterize the contact zone degree of mixing, in terms of dimensionless Peclet Number, and the contact time, in terms of residence time distribution. The tracer tests were performed at different hydraulic loading rates and recycle ratios. The experimental results confirmed that the axial dispersion model can be used to estimate the degree of mixing inside the contact zone. The results showed that the Peclet Number increased as the hydraulic loading rate increased, for all experiments performed under the same recycle ratio. In addition, the degree of mixing slightly increased as the recycle ratio increased, for all experiments performed under the same hydraulic loading rate.

Running Economy During a Simulated 60-km Trial

2014 ◽  
Vol 9 (4) ◽  
pp. 604-609 ◽  
Author(s):  
Federico Schena ◽  
Barbara Pellegrini ◽  
Cantor Tarperi ◽  
Elisa Calabria ◽  
Gian Luca Salvagno ◽  
...  
Keyword(s):  
Energy Cost ◽  
Contact Time ◽  
Stride Length ◽  
Respiratory Exchange Ratio ◽  
Central Fatigue ◽  
Serum Creatine Kinase ◽  
Running Economy ◽  
Percentage Increase ◽  
Time Points ◽  
Energy Cost Of Running

The effect of a prolonged running trial on the energy cost of running (Cr) during a 60-km ultramarathon simulation at the pace of a 100-km competition was investigated in 13 men (40.8 ± 5.6 y, 70.7 ± 5.5 kg, 177.5 ± 4.5 cm) and 5 women (40.4 ± 2.3 y, 53.7 ± 4.4 kg, 162.4 ± 4.8 cm) who participated in a 60-km trial consisting of 3 consecutive 20-km laps. Oxygen uptake (VO2) at steady state was determined at constant speed before the test and at the end of each lap; stride length (SL) and frequency and contact time were measured at the same time points; serum creatine kinase (S-CPK) was measured before and at the end of the test. Cr in J · kg−1 · m−1, as calculated from VO2ss and respiratory-exchange ratio, did not increase with distance. SL significantly decreased with distance. The net increase in S-CPK was linearly related with the percentage increase of Cr observed during the trial. It is concluded that, in spite of increased S-CPK, this effort was not able to elicit any peripheral or central fatigue or biomechanical adaptation leading to any modification of Cr.

Sled Towing: The Optimal Overload for Peak Power Production

2017 ◽  
Vol 12 (8) ◽  
pp. 1052-1058 ◽  
Author(s):  
Andrea Monte ◽  
Francesca Nardello ◽  
Paola Zamparo
Keyword(s):  
Contact Time ◽  
Peak Power ◽  
Stride Length ◽  
Power Production ◽  
Step Length ◽  
Flight Time ◽  
Sprint Training ◽  
Joint Angles ◽  
Step Number ◽  
Increasing Load

Purpose:The effects of different loads on kinematic and kinetic variables during sled towing were investigated with the aim to identify the optimal overload for this specific sprint training.Methods:Thirteen male sprinters (100-m personal best: 10.91 ± 0.14 s) performed 5 maximal trials over a 20-m distance in the following conditions: unloaded and with loads from 15% to 40% of the athlete’s body mass (BM). In these calculations the sled mass and friction were taken into account. Contact and flight times, stride length, horizontal hip velocity (vh), and relative angles of hip, knee, and ankle (at touchdown and takeoff) were measured step by step. In addition, the horizontal force (Fh) and power (Ph) and maximal force (Fh0) and power (Ph0) were calculated.Results:vh, flight time, and step length decreased while contact time increased with increasing load (P < .001). These variables changed significantly also as a function of the step number (P < .01), except between the 2 last steps. No differences were observed in Fh among loads, but Fh was larger in sled towing than in unloaded. Ph was unaffected by load up to +20%BM but decreased with larger loads. Fh0 and Ph0 were achieved at 20%BM. Up to 20%BM, no significant effects on joint angles were observed at touchdown and takeoff, while at loads >30%BM joint angles tended to decrease.Conclusion:The 20%BM condition represents the optimal overload for peak power production—at this load sprinters reach their highest power without significant changes in their running technique (eg, joint angles).

scholarly journals A Comparison of Skating Economy On-Ice and On the Skating Treadmill

2003 ◽  
Vol 28 (1) ◽  
pp. 1-11 ◽  
Author(s):  
K.J. Nobes ◽  
D.L. Montgomery ◽  
D.J. Pearsall ◽  
R.A. Turcotte ◽  
R. Lefebvre ◽  
...  
Keyword(s):  
Heart Rate ◽  
Oxygen Uptake ◽  
Stride Length ◽  
Ice Hockey ◽  
Maximum Speed ◽  
Passive Recovery ◽  
Hockey Players ◽  
Stride Rate ◽  
Volitional Fatigue

The purpose of this study was to compare skating economy and oxygen uptake (VO2) on-ice and on the skating treadmill (TM). Male varsity hockey players (n = 15, age = 21.0 yr) performed skating tests on a TM and on-ice. The subjects skated for 4 min at each of 3 submaximal velocities (18, 20, and 22 km • h−1), separated by 5 min of passive recovery. A VO2max test followed the submaximal tests and commenced at 24 km • h−1 with the velocity increasing by 1 km • hr−1 every minute until volitional fatigue. VO2 was 39.7, 42.9, 46.0, and 53.4 ml • kg−1 • min−1 at 18, 20, 22, and maximum speed (km • hr−1) on the TM. VO2 was significantly lower (p < .05) 31.5, 36.9, and 42.7 ml • kg−1 • min−1 at 18, 20, and 22 km • h−1 on-ice. The on-ice VO2max (54.7 ml • kg−1 • min−1) was similar to TM. Stride rate, stride length and heart rate (HR) were significantly different on-ice compared to TM. These results show that at submaximal velocities, VO2, HR, and stride rate are higher on TM compared to on-ice. VO2max was similar while HRmax was higher on the skating treadmill compared to on-ice. Keywords: VO2, ice hockey, stride kinetics, heart rate

scholarly journals Textured insoles reduce vertical loading rate and increase subjective plantar sensation in overground running

2018 ◽  
Vol 18 (4) ◽  
pp. 497-503 ◽  
Author(s):  
Michael Wilkinson ◽  
Alistair Ewen ◽  
Nicholas Caplan ◽  
David O’leary ◽  
Neil Smith ◽  
...  
Keyword(s):  
Loading Rate ◽  
Vertical Loading

scholarly journals Average stride length and stride rate of Thoroughbreds and Quarter Horses during ‘Sprint’ and ‘Classic’ races

2021 ◽  
Author(s):  
Fernando Benjamin Vergara-Hernandez ◽  
Brian D. Nielsen ◽  
Cara I. Robison ◽  
Taylor A. Fabus ◽  
Jasmin L. Kompare ◽  
...  
Keyword(s):  
Stride Length ◽  
Factors Influencing ◽  
Stride Rate ◽  
Main Factors

The main factors influencing speed in athletes are stride length (SL) and stride rate (SR). However, conflict remains whether SL or SR is the key determinant of higher speeds. Quarter Horses (QH) generally reach higher speeds in their races than do Thoroughbreds (TB). However, the influence of SL and SR on this greater speed is unclear. Therefore, the main objective of this study was to compare SL and SR in QH and TB raced in short (sprint) and long (classic) distances. We hypothesized that QH have a higher SR in comparison to TB, and SR decreases as distance increases. Two race distances were analyzed for each breed: QH races of 100.6 and 402.3 m, and TB races of 1,207.0 m and 2,011.7 m. Data from twenty horses were obtained, consisting of five horses from each race distance (10 QH and 10 TB). Five individuals watched recordings of each race three times counting the number of strides taken by each winning horse. The SR was calculated using the average number of strides over a given race duration, and SL was determined by calculating the total number of strides over the distance covered. Speed was calculated dividing the distance by the time of the winning horse. The PROC Mixed Procedure was used to identify statistical differences between breeds, and between distances within the same breed. Results showed that although the SL of the TB was longer in comparison with the QH (P<0.001), the average SR in QH was higher than in TB (2.88 vs 2.34 + 0.03 strides/s; P<0.001). Further, QH classic distance demonstrated a faster speed than TB at either distance (P<0.001).  In conclusion, QH achieve a higher SR in comparison to TB (between 14-20% more than TB), confirming the importance of SR in achieving high racing speeds.

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