scholarly journals Runners Adapt Different Lower-Limb Movement Patterns With Respect to Different Speeds and Downhill Slopes

2021 ◽  
Vol 3 ◽  
Author(s):  
David Sundström ◽  
Markus Kurz ◽  
Glenn Björklund
Keyword(s):  
Lower Limb ◽  
Energy Cost ◽  
Degrees Of Freedom ◽  
Stance Phase ◽  
Sagittal Plane ◽  
Three Dimensional ◽  
Movement Pattern ◽  
Knee Extension ◽  
Generic Model ◽  
Energy Cost Of Running

The aim of this study was to investigate the influence of slope and speed on lower-limb kinematics and energy cost of running. Six well-trained runners (VO2max 72 ± 6 mL·kg−1·min−1) were recruited for the study and performed (1) VO2max and energy cost tests and (2) an experimental running protocol at two speeds, 12 km·h−1 and a speed corresponding to 80% of VO2max (V80, 15.8 ± 1.3 km·h−1) on three different slopes (0°, −5°, and −10°), totaling six 5-min workload conditions. The workload conditions were randomly ordered and performed continuously. The tests lasted 30 min in total. All testing was performed on a large treadmill (3 × 5 m) that offered control over both speed and slope. Three-dimensional kinematic data of the right lower limb were captured during the experimental running protocol using eight infrared cameras with a sampling frequency of 150 Hz. Running kinematics were calculated using a lower body model and inverse kinematics approach. The generic model contained three, one, and two degrees of freedom at the hip, knee, and ankle joints, respectively. Oxygen uptake was measured throughout the experimental protocol. Maximum hip extension and flexion during the stance phase increased due to higher speed (p < 0.01 and p < 0.01, respectively). Knee extension at the touchdown and maximal knee flexion in the stance phase both increased on steeper downhill slopes (both p < 0.05). Ground contact time (GCT) decreased as the speed increased (p < 0.01) but was unaffected by slope (p = 0.73). Runners modified their hip movement pattern in the sagittal plane in response to changes in speed, whereas they altered their knee movement pattern during the touchdown and stance phases in response to changes in slope. While energy cost of running was unaffected by speed alone (p = 0.379), a shift in energy cost was observed for different speeds as the downhill gradient increased (p < 0.001). Energy cost was lower at V80 than 12 km·h−1 on a −5° slope but worse on a −10° slope. This indicates that higher speeds are more efficient on moderate downhill slopes (−5°), while lower speeds are more efficient on steeper downhill slopes (−10°).

scholarly journals Adaptations for economical bipedal running: the effect of limb structure on three-dimensional joint mechanics

2010 ◽  
Vol 8 (58) ◽  
pp. 740-755 ◽  
Author(s):  
Jonas Rubenson ◽  
David G. Lloyd ◽  
Denham B. Heliams ◽  
Thor F. Besier ◽  
Paul A. Fournier
Keyword(s):  
Elastic Energy ◽  
Energy Cost ◽  
Stance Phase ◽  
External Rotation ◽  
Three Dimensional ◽  
Mechanical Power ◽  
Joint Mechanics ◽  
Joint Power ◽  
Energy Cost Of Running ◽  
Limb Structure

The purpose of this study was to examine the mechanical adaptations linked to economical locomotion in cursorial bipeds. We addressed this question by comparing mass-matched humans and avian bipeds (ostriches), which exhibit marked differences in limb structure and running economy. We hypothesized that the nearly 50 per cent lower energy cost of running in ostriches is a result of: (i) lower limb-swing mechanical power, (ii) greater stance-phase storage and release of elastic energy, and (iii) lower total muscle power output. To test these hypotheses, we used three-dimensional joint mechanical measurements and a simple model to estimate the elastic and muscle contributions to joint work and power. Contradictory to our first hypothesis, we found that ostriches and humans generate the same amounts of mechanical power to swing the limbs at a similar self-selected running speed, indicating that limb swing probably does not contribute to the difference in energy cost of running between these species. In contrast, we estimated that ostriches generate 120 per cent more stance-phase mechanical joint power via release of elastic energy compared with humans. This elastic mechanical power occurs nearly exclusively at the tarsometatarso-phalangeal joint, demonstrating a shift of mechanical power generation to distal joints compared with humans. We also estimated that positive muscle fibre power is 35 per cent lower in ostriches compared with humans, and is accounted for primarily by higher capacity for storage and release of elastic energy. Furthermore, our analysis revealed much larger frontal and internal/external rotation joint loads during ostrich running than in humans. Together, these findings support the hypothesis that a primary limb structure specialization linked to economical running in cursorial species is an elevated storage and release of elastic energy in tendon. In the ostrich, energy-saving specializations may also include passive frontal and internal/external rotation load-bearing mechanisms.

scholarly journals Biologically Inspired Design and Development of a Variable Stiffness Powered Ankle-Foot Prosthesis

2019 ◽  
Vol 11 (4) ◽  
Author(s):  
Alexander Agboola-Dobson ◽  
Guowu Wei ◽  
Lei Ren
Keyword(s):  
Lower Limb ◽  
Degrees Of Freedom ◽  
Sagittal Plane ◽  
Frontal Plane ◽  
Variable Stiffness ◽  
Plane Motion ◽  
Biologically Inspired ◽  
Passive Rotation ◽  
Ground Conditions ◽  
Biologically Inspired Design

Recent advancements in powered lower limb prostheses have appeased several difficulties faced by lower limb amputees by using a series-elastic actuator (SEA) to provide powered sagittal plane flexion. Unfortunately, these devices are currently unable to provide both powered sagittal plane flexion and two degrees of freedom (2-DOF) at the ankle, removing the ankle’s capacity to invert/evert, thus severely limiting terrain adaption capabilities and user comfort. The developed 2-DOF ankle system in this paper allows both powered flexion in the sagittal plane and passive rotation in the frontal plane; an SEA emulates the biomechanics of the gastrocnemius and Achilles tendon for flexion while a novel universal-joint system provides the 2-DOF. Several studies were undertaken to thoroughly characterize the capabilities of the device. Under both level- and sloped-ground conditions, ankle torque and kinematic data were obtained by using force-plates and a motion capture system. The device was found to be fully capable of providing powered sagittal plane motion and torque very close to that of a biological ankle while simultaneously being able to adapt to sloped terrain by undergoing frontal plane motion, thus providing 2-DOF at the ankle. These findings demonstrate that the device presented in this paper poses radical improvements to powered prosthetic ankle-foot device (PAFD) design.

Energy Cost of Running in Well-Trained Athletes: Toward Slope-Dependent Factors

2021 ◽  
pp. 1-9
Author(s):  
Marcel Lemire ◽  
Romain Remetter ◽  
Thomas J. Hureau ◽  
Bernard Geny ◽  
Evelyne Lonsdorfer ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Lower Limb ◽  
Energy Cost ◽  
Cardiovascular Responses ◽  
Maximum Oxygen Consumption ◽  
Step Frequency ◽  
Physiological Factors ◽  
Vertical Stiffness ◽  
Energy Cost Of Running ◽  
Level Running

Purpose: This study aimed to determine the contribution of metabolic, cardiopulmonary, neuromuscular, and biomechanical factors to the energy cost (ECR) of graded running in well-trained runners. Methods: Eight men who were well-trained trail runners (age: 29 [10] y, mean [SD]; maximum oxygen consumption: 68.0 [6.4] mL·min−1·kg−1) completed maximal isometric evaluations of lower limb extensor muscles and 3 randomized trials on a treadmill to determine their metabolic and cardiovascular responses and running gait kinematics during downhill (DR: −15% slope), level (0%), and uphill running (UR: 15%) performed at similar O2 uptake (approximately 60% maximum oxygen consumption). Results: Despite similar O2 demand, ECR was lower in DR versus level running versus UR (2.5 [0.2] vs 3.6 [0.2] vs 7.9 [0.5] J·kg−1·m−1, respectively; all P < .001). Energy cost of running was correlated between DR and level running conditions only (r2 = .63; P = .018). Importantly, while ECR was correlated with heart rate, cardiac output, and arteriovenous O2 difference in UR (all r2 > .50; P < .05), ECR was correlated with lower limb vertical stiffness, ground contact time, stride length, and step frequency in DR (all r2 > .58; P < .05). Lower limb isometric extension torques were not related to ECR whatever the slope. Conclusion: The determining physiological factors of ECR might be slope specific, mainly metabolic and cardiovascular in UR versus mainly neuromuscular and mechanical in DR. This possible slope specificity of ECR during incline running opens the way for the implementation of differentiated physiological evaluations and training strategies to optimize performance in well-trained trail runners.

Effect of prosthetic ankle units on the gait of persons with bilateral trans-femoral amputations

2008 ◽  
Vol 32 (1) ◽  
pp. 111-126 ◽  
Author(s):  
Lexyne L. McNealy ◽  
Steven A. Gard
Keyword(s):  
Power Generation ◽  
Range Of Motion ◽  
Ankle Joint ◽  
Lower Limb ◽  
Stance Phase ◽  
Sagittal Plane ◽  
The Body ◽  
Control Group ◽  
Initial Contact ◽  
Ankle Motion

In able-bodied individuals, the ankle joint functions to provide shock absorption, aid in foot clearance during the swing phase, and provides a rocker mechanism during stance phase to facilitate forward progression of the body. Prosthetic ankles currently used by persons with lower limb amputations provide considerably less function than their anatomical counterparts. However, increased ankle motion in the sagittal plane may improve the gait of persons with lower limb amputations while providing a more versatile prosthesis. The primary aim of this study was to examine and quantify temporal-spatial, kinematic, and kinetic changes in the gait of four male subjects with bilateral trans-femoral amputations who walked with and without prosthetic ankle units. Two prosthesis configurations were examined: (i) Baseline with only two Seattle LightFoot2 prosthetic feet, and (ii) with the addition of Endolite Multiflex Ankle units. Data from the gait analyses were compared between prosthetic configurations and with a control group of able-bodied subjects. The amputee subjects' freely-selected walking speeds, 0.74 ± 0.19 m/s for the Baseline condition and 0.81 ± 0.15 m/s with the ankle units, were much less than that of the control subjects (1.35 ± 0.10 m/s). The amputee subjects demonstrated no difference in walking speed, step length, cadence, or ankle, knee, and hip joint moments and powers between the two prosthesis configurations. Sagittal plane ankle range of motion, however, increased by 3–8° with the addition of the prosthetic ankle units. Compared to the control group, following initial contact the amputee subjects passively increased the rate of energy storage or dissipation at the prosthetic ankle joint, actively increased the power generation at the hip, and increased the extension moment at the hip while wearing the prosthetic ankle configuration. The amputee subjects increased the power generation at their hips, possibly as compensation for the reduced rate of energy return at their prosthetic ankles. Results from subject questionnaires administered following the gait analyses revealed that the prosthetic ankle units provided more comfort during gait and did not increase the perceived effort to walk. The subjects also indicated that they preferred walking with the prosthetic ankle units compared to the Baseline configuration. The results of the study showed that the prosthetic ankle units improved sagittal plane ankle range of motion and increased the comfort and functionality of the amputee subjects’ prostheses by restoring a significant portion of the ankle rocker mechanism during stance phase. Therefore, prosthetic ankle mechanisms should be considered a worthwhile option when prostheses are prescribed for persons with trans-femoral amputations.

scholarly journals Mechanism of anterior cruciate ligament loading during dynamic motor tasks

2020 ◽  
Author(s):  
Azadeh Nasseri ◽  
David G Lloyd ◽  
Adam L Bryant ◽  
Jonathon Headrick ◽  
Timothy Sayer ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Lower Limb ◽  
Muscle Activation ◽  
Sagittal Plane ◽  
Cruciate Ligament ◽  
Three Dimensional ◽  
Whole Body ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
Anterior Cruciate

AbstractThis study determined anterior cruciate ligament (ACL) force and its contributors during a standardized drop-land-lateral jump task using a validated computational model. Healthy females (n=24) who were recreationally active performed drop-land-lateral jump and straight run tasks. Three-dimensional whole-body kinematics, ground reaction forces, and muscle activation patterns from eight lower limb muscles were collected concurrently during both tasks, but only the jump was analyzed computationally, with the run included for model calibration. External biomechanics, muscle-tendon unit kinematics, and muscle activation patterns were used to model lower limb muscle and ACL forces. Peak ACL force (2.3±0.5 BW) was observed at 13% of the stance phase during the drop-land-lateral jump task. The ACL force was primarily developed through the sagittal plane, and muscle was the dominant source of ACL loading. The gastrocnemii and quadriceps were main ACL antagonists (i.e., loaders), while hamstrings were the main ACL agonists (i.e., supporters).

scholarly journals Correlation between cardiopulmonary metabolic energy cost and lower-limb muscle activity during inclined treadmill gait in older adults

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jihye Kim ◽  
Hwang-Jae Lee ◽  
Su-Hyun Lee ◽  
Jungsoo Lee ◽  
Won Hyuk Chang ◽  
...  
Keyword(s):  
Older Adults ◽  
Lower Limb ◽  
Muscle Activity ◽  
Energy Cost ◽  
Stance Phase ◽  
Treadmill Walking ◽  
Metabolic Energy ◽  
Lower Limb Muscle ◽  
Limb Muscle ◽  
Increased Activity

Abstract Background Inclined walking requires more cardiopulmonary metabolic energy and muscle strength than flat-level walking. This study sought to investigate changes in lower-limb muscle activity and cardiopulmonary metabolic energy cost during treadmill walking with different inclination grades and to discern any correlation between these two measures in older adults. Methods Twenty-four healthy older adults (n = 11 males; mean age: 75.3 ± 4.0 years) participated. All participants walked on a treadmill that was randomly inclined at 0% (condition 1), 10% (condition 2), and 16% (condition 3) for five minutes each. Simultaneous measurements of lower-limb muscle activity and cardiopulmonary metabolic energy cost during inclined treadmill walking were collected. Measured muscles included the rectus abdominis (RA), erector spinae (ES), rectus femoris (RF), biceps femoris (BF), vastus medialis (VM), tibialis anterior (TA), medial head of the gastrocnemius (GCM), and soleus (SOL) muscles on the right side. Results As compared with 0% inclined treadmill gait, the 10% inclined treadmill gait increased the net cardiopulmonary metabolic energy cost by 22.9%, while the 16% inclined treadmill gait increased the net cardiopulmonary metabolic energy cost by 44.2%. In the stance phase, as the slope increased, activity was significantly increased in the RA, RF, VM, BF, GCM, and SOL muscles. In the swing phase, As the slope increased activity was significantly increased in the RA, RF, VM, BF, and TA muscles. SOL muscle activity was most relevant to the change in cardiopulmonary metabolic energy cost in the stance phase of inclined treadmill walking. The relationship between the increase in cardiopulmonary metabolic energy cost and changes in muscle activity was also significant in the VM, GCM, and RF. Conclusion This study demonstrated that changes in SOL, VM, GCM, and RA muscle activity had a significant relationship with cardiopulmonary metabolic energy cost increment during inclined treadmill walking. These results can be used as basic data for various gait-training programs and as an indicator in the development of assistive algorithms of wearable walking robots for older adults. Trial registration Clinical trials registration information: ClinicalTrials.gov Identifier: NCT04614857 (05/11/2020).

scholarly journals Wearable Sensors Detect Differences between the Sexes in Lower Limb Electromyographic Activity and Pelvis 3D Kinematics during Running

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6478
Author(s):  
Iván Nacher Moltó ◽  
Juan Pardo Albiach ◽  
Juan José Amer-Cuenca ◽  
Eva Segura-Ortí ◽  
Willig Gabriel ◽  
...  
Keyword(s):  
Lower Limb ◽  
Muscle Activation ◽  
Stance Phase ◽  
Inertial Sensor ◽  
Scientific Evidence ◽  
Wearable Sensors ◽  
Three Dimensional ◽  
Gluteus Maximus ◽  
Electromyographic Activity ◽  
Men And Women

Each year, 50% of runners suffer from injuries. Consequently, more studies are being published about running biomechanics; these studies identify factors that can help prevent injuries. Scientific evidence suggests that recreational runners should use personalized biomechanical training plans, not only to improve their performance, but also to prevent injuries caused by the inability of amateur athletes to tolerate increased loads, and/or because of poor form. This study provides an overview of the different normative patterns of lower limb muscle activation and articular ranges of the pelvis during running, at self-selected speeds, in men and women. Methods: 38 healthy runners aged 18 to 49 years were included in this work. We examined eight muscles by applying two wearable superficial electromyography sensors and an inertial sensor for three-dimensional (3D) pelvis kinematics. Results: the largest differences were obtained for gluteus maximus activation in the first double float phase (p = 0.013) and second stance phase (p = 0.003), as well as in the gluteus medius in the second stance phase (p = 0.028). In both cases, the activation distribution was more homogeneous in men and presented significantly lower values than those obtained for women. In addition, there was a significantly higher percentage of total vastus medialis activation in women throughout the running cycle with the median (25th–75th percentile) for women being 12.50% (9.25–14) and 10% (9–12) for men. Women also had a greater range of pelvis rotation during running at self-selected speeds (p = 0.011). Conclusions: understanding the differences between men and women, in terms of muscle activation and pelvic kinematic values, could be especially useful to allow health professionals detect athletes who may be at risk of injury.

scholarly journals Kinematic gait analysis of a young man after amputation of the toes

2014 ◽  
Vol 6 (1) ◽  
Author(s):  
Wanda Forczek ◽  
Tadeusz Ruchlewicz ◽  
Anna Gawęda
Keyword(s):  
Lower Limb ◽  
Fear Of Falling ◽  
Sagittal Plane ◽  
Body Height ◽  
Three Dimensional ◽  
The Body ◽  
Mean Values ◽  
Stable Conditions ◽  
Partial Amputation ◽  
The Subject

Summary Study aim: the foot is recognised as a “functional unit” with two important aims: to support body weight and to serve as a lever to propel the body forward. When it is impaired, the locomotor pattern has to adapt to compensate for the dysfunction. The purpose of this study was to investigate gait kinematics of a man after bilateral partial amputation of the toes. Material and methods: the subject of the study was a young man aged 30 years (body height and mass: 186 cm, 82 kg) who suffered a frostbite injury in the feet while climbing in the severe mountain conditions. After a few months of treatment, the necessary amputation occurred. Three-dimensional lower limb kinematics was collected from motion capture system (Vicon 250) and Golem marker set-up using 5 video-based cameras with infrared strobes. The subject performed over-ground walking at self-selected speed, first barefoot, then wearing athletic shoes. Results: the patient’s results are the mean values of sixteen full gait cycles. The spatiotemporal parameters were lower during gait without shoes. In terms of the angular changes of the lower limb joints in sagittal plane, the analysis revealed similar functional patterns and typical trends in both recorded conditions. The differences, however, occurred in their amplitude. A larger range of motion was generally noted in shod conditions. The higher the joint was, the smaller the differences were. Conclusion: changes in gait due to the forefoot dysfunction may be stabilizing adaptations related to fear of falling. Footwear provided more stable conditions.

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