Biomechanical adaptation of preferred transition speed during an incremental test in a gradient slope

Humans prefer to walk at slow speeds and to run at fast speeds. In between, there is a speed at which people choose to transition between gaits, the Preferred Transition Speed (PTS). At slow speeds, it is energetically cheaper to walk and at faster speeds, it is cheaper to run. Thus, there is an intermediate speed, the Energetically Optimal Transition Speed (EOTS). Our goals were to determine: 1) how PTS and EOTS compare across a wide range of inclines and 2) if the EOTS can be predicted by the heart rate optimal transition speed (HROTS). Ten healthy, high-caliber, male trail/mountain runners participated. On day 1, subjects completed 0° and 15° trials and on day 2, 5° and 10°. We calculated PTS as the average of the walk-to-run transition speed (WRTS) and the run-to-walk transition speed (RWTS) determined with an incremental protocol. We calculated EOTS and HROTS from energetic cost and heart rate data for walking and running near the expected EOTS for each incline. The intersection of the walking and running linear regression equations defined EOTS and HROTS. We found that PTS, EOTS, and HROTS all were slower on steeper inclines. PTS was slower than EOTS at 0°, 5°, and 10°, but the two converged at 15°. Across all inclines, PTS and EOTS were only moderately correlated. Although EOTS correlated with HROTS, EOTS was not predicted accurately by heart rate on an individual basis.

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Age-Related Differences in Perceived Exertion While Walking and Running Near the Preferred Transition Speed

Pediatric Exercise Science ◽

10.1123/pes.2019-0233 ◽

2020 ◽

Vol 32 (4) ◽

pp. 227-232

Author(s):

Stacey M. Kung ◽

Philip W. Fink ◽

Stephen J. Legg ◽

Ajmol Ali ◽

Sarah P. Shultz

Keyword(s):

Oxygen Consumption ◽

Oxygen Uptake ◽

Relative Intensity ◽

Perceived Exertion ◽

Age Groups ◽

Peak Oxygen Uptake ◽

Transition Speed ◽

Age Related ◽

All Speeds ◽

Preferred Transition Speed

Purpose: To investigate whether youth and adults can perceive differences in exertion between walking and running at speeds near the preferred transition speed (PTS) and if there are age-related differences in these perceptions. Methods: A total of 49 youth (10–12 y, n = 21; 13–14 y, n = 10; 15–17 y, n = 18) and 13 adults (19–29 y) completed a walk-to-run transition protocol to determine PTS and peak oxygen uptake. The participants walked and ran on a treadmill at 5 speeds (PTS–0.28 m·s−1, PTS–0.14 m·s−1, PTS, PTS+0.14 m·s−1, PTS+0.28 m·s−1) and rated perceived exertion using the OMNI Perceived Exertion (OMNI-RPE) scale. Oxygen consumption was measured during the walk-to-run transition protocol to obtain the relative intensity (percentage of peak oxygen uptake) at PTS. OMNI-RPE scores at all speeds and percentage of peak oxygen uptake at PTS were compared between age groups. Results: The 10- to 12-year-olds transitioned at a higher percentage of peak oxygen uptake than adults (64.54 [10.18] vs 52.22 [11.40], respectively; P = .035). The 10- to 14-year-olds generally reported higher OMNI-RPE scores than the 15- to 17-year-olds and adults (P < .050). In addition, the 10- to 14-year-olds failed to distinguish differences in OMNI-RPE between walking and running at PTS and PTS+0.14 m·s−1. Conclusions: Children aged 10–14 years are less able to distinguish whether walking or running requires less effort at speeds near the PTS compared with adults. The inability to judge which gait mode is less demanding could hinder the ability to minimize locomotive demands.

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An Electromyographical Analysis of the Role of Dorsiflexors on the Gait Transition during Human Locomotion

Journal of Applied Biomechanics ◽

10.1123/jab.17.4.287 ◽

2001 ◽

Vol 17 (4) ◽

pp. 287-296 ◽

Cited By ~ 21

Author(s):

Alan Hreljac ◽

Alan Arata ◽

Reed Ferber ◽

John A. Mercer ◽

Brandi S. Row

Keyword(s):

Tibialis Anterior ◽

Walking Speed ◽

Vastus Lateralis ◽

Human Locomotion ◽

Medial Gastrocnemius ◽

Energetic Cost ◽

Emg Activity ◽

Gait Transition ◽

Transition Speed ◽

Preferred Transition Speed

Previous research has demonstrated that the preferred transition speed during human locomotion is the speed at which critical levels of ankle angular velocity and acceleration (in the dorsiflexor direction) are reached, leading to the hypothesis that gait transition occurs to alleviate muscular stress on the dorsiflexors. Furthermore, it has been shown that the metabolic cost of running at the preferred transition speed is greater than that of walking at that speed. This increase in energetic cost at gait transition has been hypothesized to occur due to a greater demand being placed on the larger muscles of the lower extremity when gait changes from a walk to a run. This hypothesis was tested by monitoring electromyographic (EMG) activity of the tibialis anterior, medial gastrocnemius, vastus lateralis, biceps femoris, and gluteus maximus while participants (6 M, 3 F) walked at speeds of 70, 80, 90, and 100% of their preferred transition speed, and ran at their preferred transition speed. The EMG activity of the tibialis anterior increased as walking speed increased, then decreased when gait changed to a run at the preferred transition speed. Concurrently, the EMG activity of all other muscles that were monitored increased with increasing walking speed, and at a greater rate when gait changed to a run at the preferred transition speed. The results of this study supported the hypothesis presented.

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Changes in the Preferred Transition Speed With Added Mass to the Foot

Journal of Applied Biomechanics ◽

10.1123/jab.2013-0041 ◽

2014 ◽

Vol 30 (1) ◽

pp. 95-103 ◽

Cited By ~ 5

Author(s):

Toran D. MacLeod ◽

Alan Hreljac ◽

Rodney Imamura

Keyword(s):

Angular Velocity ◽

Critical Level ◽

Angular Acceleration ◽

Gait Transition ◽

Joint Power ◽

Transition Speed ◽

Dependent Variables ◽

Incremental Protocol ◽

Preferred Transition Speed ◽

Male Subjects

This study was conducted to investigate whether adding mass to subjects’ feet affects the preferred transition speed (PTS), and to ascertain whether selected swing phase variables (maximum ankle dorsiflexion angular velocity, angular acceleration, joint moment, and joint power) are determinants of the PTS, based upon four previously established criteria. After the PTS of 24 healthy active male subjects was found, using an incremental protocol in loaded (2 kg mass added to each shoe) and unloaded (shoes only) conditions, subjects walked at three speeds (60%, 80%, and 100% of PTS) and ran at one speed (100% of PTS) on a motor-driven treadmill while relevant data were collected. The PTS of the unloaded condition (2.03 ± 0.12 m/s) was significantly greater (P< .05) than the PTS of the loaded condition (1.94 ± 0.13 m/s). Within both load conditions, all dependent variables increased significantly with walking speed, decreased significantly when gait changed to a run, and were assumed to provide the necessary input to signal a gait transition, fulfilling the requirements of the first three criteria, but only ankle angular velocity reached a critical level before the transition, satisfying all four criteria to be considered a determinant of the PTS.

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Can the Center of Mass Reflect the Metabolic Expenditure?

Asian Journal of Physical Education & Recreation ◽

10.24112/ajper.161786 ◽

2010 ◽

Vol 16 (1) ◽

pp. 16-21

Author(s):

Ying ki FUNG ◽

Tyzz yuang SHIANG

Keyword(s):

Pulmonary Ventilation ◽

Center Of Mass ◽

Metabolic Cost ◽

The Past ◽

Transition Speed ◽

Wide Range ◽

Locomotion Pattern ◽

Metabolic Expenditure ◽

Analysis System ◽

Preferred Transition Speed

LANGUAGE NOTE | Document text in English; abstract also in Chinese. In the past studies, the movement of center or mass (COM) was one of the descriptor to estimate the metabolic expenditure. However, the sensitivity of this method among the wide range speed, the locomotion pattern and during the Energetically Optimal Transition Speed (EOTS) is still unexplored. Hence that, the purpose of this investigation was to determine the metabolic and COM pattern differences between walk and run among the EOTS with a reflective marker motion analysis system and indirect pulmonary ventilation machine. The results showed that there is a metabolic intersection on two locomotion patterns (walk and run) between 100 and 125% Preferred Transition Speed (PTS), which coincides with the past EOTS studies, whereas, COM result showed that the variation of vertical COM displacement for running is significantly higher than walking among the entire tested speed. The pattern between the metabolic and COM variables is an inverse relation after the EOTS. Hence, the present investigator doubted that there would be a reliability problem for those instruments which use the COM displacement to estimate the metabolic cost or the intensity of physical activity among 5.15 to 9.82km/h for walk and run. 在過去的研究，身體質量中心移動常常被用作評估身體耗能的一種方法。可是這種方法在不同速度、動作型態及最佳轉換速度(EOTS)之可信範圍一直都沒有作出深入探討。因此本研究目的希望利用動作及生理分析系統對身體中心及身體耗能在兩種動作型態(走和跑)和在EOTS的情況底下的趨勢上作出分析及探討。結果顯示在兩個動作型態上在100及125%自然轉換速度情況下身體耗能出現交叉點(EOTS)，而此發現與過去EOTS之文獻相吻合，反之身體質量中心結果顯示，跑步在身體質量中心之穩定性在所有測試速度情況下都比走路有統計上之差異，跑步的垂直位移變異量明顯比走路大。由此可見身體耗能及身體質量中心變異量顯示出兩者在EOTS出現後是反比關係。因此本研究結果可推斷現在有利用身體質量中心變異量去推估身體耗能或身體活動量的儀器在速度5.15—9.82公里的情況底下可能會出現信度問題。

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Walking at speeds close to the preferred transition speed as an approach to obesity treatment

Srpski arhiv za celokupno lekarstvo ◽

10.2298/sarh1202058i ◽

2012 ◽

Vol 140 (1-2) ◽

pp. 58-64 ◽

Cited By ~ 4

Author(s):

Dusko Ilic ◽

Vladimir Ilic ◽

Vladimir Mrdakovic ◽

Nenad Filipovic

Keyword(s):

Weight Loss ◽

Body Weight ◽

Fat Mass ◽

Repeated Measures ◽

Fat Free Mass ◽

Exercise Protocol ◽

Significant Group ◽

Functional Changes ◽

Transition Speed ◽

Preferred Transition Speed

Introduction. Increasing energy expenditure through certain exercise is an important component of effective interventions to enhance initial weight loss and prevent weight regain. Objective. The purpose of this study was to determine the effect of a 16-week weight loss exercise programme on morpho-functional changes in female adults and to examine the programme effects on two subpopulations with different levels of obesity. Methods. Fifty-six middle-aged women were divided into 2 groups according to their body mass index (BMI): 25-29.9 kg/m2 - overweight (OW) and ?30 kg/m2 - obese (OB). The exercise protocol included a walking technique based on hip rotation at horizontal plane at speeds close to the preferred transition speed (PTS). At the initiation of the study and after 16 weeks of the programme, anthropometric, morphological and cardiovascular parameters of all subjects were assessed. The main effects of Group (OW and OB) and Time and the interaction effect of Group by Time were tested by time repeated measures General Linear Model (mixed between-within subjects ANOVA). Results. Mean weight loss during the programme was 10.3 kg and 20.1 kg in OW and OB, respectively. The average fat mass (FM) loss was 9.4 kg in OW and 16.9 kg in OB. The Mixed ANOVA revealed a significant Group by Time interaction effects for waist circumference, body weight, body water, fat free mass, FM, %FM and BMI (p<0.05). Conclusion. The applied exercise protocol has proved as beneficial in the treatment of obesity, since it resulted in a significant weight loss and body composition changes. The reduction in body weight was achieved mainly on account of the loss of fat mass.

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Swing- and support-related muscle actions differentially trigger human walk–run and run–walk transitions

Journal of Experimental Biology ◽

10.1242/jeb.204.13.2277 ◽

2001 ◽

Vol 204 (13) ◽

pp. 2277-2287 ◽

Cited By ~ 11

Author(s):

Boris I. Prilutsky ◽

Robert J. Gregor

Keyword(s):

Muscle Activation ◽

Rectus Femoris ◽

Swing Phase ◽

Knee Extensors ◽

Electromyographic Activity ◽

Sense Of Effort ◽

Leg Muscles ◽

Transition Speed ◽

Walking Speeds ◽

Preferred Transition Speed

SUMMARY There has been no consistent explanation as to why humans prefer changing their gait from walking to running and from running to walking at increasing and decreasing speeds, respectively. This study examined muscle activation as a possible determinant of these gait transitions. Seven subjects walked and ran on a motor-driven treadmill for 40s at speeds of 55, 70, 85, 100, 115, 130 and 145% of the preferred transition speed. The movements of subjects were videotaped, and surface electromyographic activity was recorded from seven major leg muscles. Resultant moments at the leg joints during the swing phase were calculated. During the swing phase of locomotion at preferred running speeds (115, 130, 145%), swing-related activation of the ankle, knee and hip flexors and peaks of flexion moments were typically lower (P<0.05) during running than during walking. At preferred walking speeds (55, 70, 85%), support-related activation of the ankle and knee extensors was typically lower during stance of walking than during stance of running (P<0.05). These results support the hypothesis that the preferred walk–run transition might be triggered by the increased sense of effort due to the exaggerated swing-related activation of the tibialis anterior, rectus femoris and hamstrings; this increased activation is necessary to meet the higher joint moment demands to move the swing leg during fast walking. The preferred run–walk transition might be similarly triggered by the sense of effort due to the higher support-related activation of the soleus, gastrocnemius and vastii that must generate higher forces during slow running than during walking at the same speed.

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In vivo behavior of the human soleus muscle with increasing walking and running speeds

Journal of Applied Physiology ◽

10.1152/japplphysiol.00128.2015 ◽

2015 ◽

Vol 118 (10) ◽

pp. 1266-1275 ◽

Cited By ~ 74

Author(s):

Adrian Lai ◽

Glen A. Lichtwark ◽

Anthony G. Schache ◽

Yi-Chung Lin ◽

Nicholas A. T. Brown ◽

...

Keyword(s):

Steady State ◽

Inverse Dynamics ◽

Length Change ◽

Shortening Velocity ◽

Transition Speed ◽

Muscle Fascicle ◽

Muscle Fascicles ◽

Inverse Dynamics Analysis ◽

Preferred Transition Speed

The interaction between the muscle fascicle and tendon components of the human soleus (SO) muscle influences the capacity of the muscle to generate force and mechanical work during walking and running. In the present study, ultrasound-based measurements of in vivo SO muscle fascicle behavior were combined with an inverse dynamics analysis to investigate the interaction between the muscle fascicle and tendon components over a broad range of steady-state walking and running speeds: slow-paced walking (0.7 m/s) through to moderate-paced running (5.0 m/s). Irrespective of a change in locomotion mode (i.e., walking vs. running) or an increase in steady-state speed, SO muscle fascicles were found to exhibit minimal shortening compared with the muscle-tendon unit (MTU) throughout stance. During walking and running, the muscle fascicles contributed only 35 and 20% of the overall MTU length change and shortening velocity, respectively. Greater levels of muscle activity resulted in increasingly shorter SO muscle fascicles as locomotion speed increased, both of which facilitated greater tendon stretch and recoil. Thus the elastic tendon contributed the majority of the MTU length change during walking and running. When transitioning from walking to running near the preferred transition speed (2.0 m/s), greater, more economical ankle torque development is likely explained by the SO muscle fascicles shortening more slowly and operating on a more favorable portion (i.e., closer to the plateau) of the force-length curve.

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