Lower Extremity Joint Work During Acceleration, Deceleration, and Steady State Running

2017 ◽  
Vol 33 (1) ◽  
pp. 56-63 ◽  
Author(s):  
D.S. Blaise Williams ◽  
Jonathan H. Cole ◽  
Douglas W. Powell
Keyword(s):  
Steady State ◽  
Lower Extremity ◽  
Sagittal Plane ◽  
Three Dimensional ◽  
Joint Work ◽  
Negative Work ◽  
Relative Contribution ◽  
Acceleration And Deceleration ◽  
The Individual ◽  
Positive Work

Running during sports and for physical activity often requires changes in velocity through acceleration and deceleration. While it is clear that lower extremity biomechanics vary during these accelerations and decelerations, the work requirements of the individual joints are not well understood. The purpose of this investigation was to measure the sagittal plane mechanical work of the individual lower extremity joints during acceleration, deceleration, and steady-state running. Ten runners were compared during acceleration, deceleration, and steady-state running using three-dimensional kinematics and kinetics measures. Total positive and negative joint work, and relative joint contributions to total work were compared between conditions. Total positive work progressively increased from deceleration to acceleration. This was due to greater ankle joint work during acceleration. While there was no significant change in total negative work during deceleration, there was a greater relative contribution of the knee to total negative work with a subsequent lower relative ankle negative work. Each lower extremity joint exhibits distinct functional roles in acceleration compared with deceleration during level running. Deceleration is dominated by greater contributions of the knee to negative work while acceleration is associated with a greater ankle contribution to positive work.

scholarly journals The contributions of ankle, knee and hip joint work to individual leg work change during uphill and downhill walking over a range of speeds

2018 ◽  
Vol 5 (8) ◽  
pp. 180550 ◽  
Author(s):  
Jana R. Montgomery ◽  
Alena M. Grabowski
Keyword(s):  
Knee Joint ◽  
Ankle Joint ◽  
Hip Joint ◽  
Sagittal Plane ◽  
Assistive Devices ◽  
Joint Work ◽  
Negative Work ◽  
Plane Joint ◽  
All Speeds ◽  
Positive Work

The muscles surrounding the ankle, knee and hip joints provide 42, 16 and 42%, respectively, of the total leg positive power required to walk on level ground at various speeds. However, each joint's contribution to leg work when walking up/downhill at a range of speeds is not known. Determining each biological joint's contribution to leg work over a range of speeds and slopes can inform the design of biomimetic assistive devices (i.e. prostheses). Twenty healthy adults walked 1.00, 1.25 and 1.50 m s −1 on 0°, ±3°, ±6° and ±9° while we collected kinematic and kinetic data. We calculated sagittal plane joint work and individual leg work over the entire stance phase. The ratio of ankle joint to total individual leg positive work (summed ankle, knee and hip joint work) did not change (0.42) with speed or slope, but the ratio of ankle joint to individual leg negative work was 0.38 at −9°, 0.42 at 0° and 0.27 at +9° across all speeds. The ratio of ankle joint to total individual leg negative work was 0.41 at 1.00 m s −1 and 0.32 at 1.50 m s −1 across all slopes. The ratio of knee joint to total individual positive leg work (0.22) did not change with speed or slope. The ratio of knee joint to total individual leg negative work was 0.39 at 1.00 m s −1 and 0.45 at 1.50 m s −1 across all slopes. The ratio of hip joint to total individual leg positive work did not change with speed but was 0.34 at −9°, 0.33 at 0° and 0.37 at +9° across all speeds. The ratio of hip joint to total individual leg negative work was 0.21 at 1.00 m s −1 , and 0.24 at 1.50 m s −1 across all slopes and 0.17 at −9°, 0.19 at 0° and 0.29 at +9° across all speeds. The ankle significantly contributes to walking on slopes and this contribution changes during sloped compared with level-ground walking, thus assistive devices that provide biomimetic ankle function must adapt to accommodate walking at different speeds and slopes; whereas assistive biomimetic devices for the knee only need to adapt at different speeds.

The Effect of Subtalar Arthrodesis Alignment on Ankle Biomechanics

2012 ◽  
Author(s):  
James R. Jastifer ◽  
Peter A. Gustafson ◽  
Robert R. Gorman
Keyword(s):  
Lower Extremity ◽  
Range Of Motion ◽  
Ankle Joint ◽  
Sagittal Plane ◽  
Three Dimensional ◽  
Neutral Position ◽  
Moment Arms ◽  
Subtalar Arthrodesis ◽  
Force Moment ◽  
Ankle Biomechanics

Background: The position, axis, and control of each lower extremity joint intimately affects adjacent joint function as well as whole limb performance. There is little describing the biomechanics of subtalar arthrodesis and none describing the effect that subtalar arthrodesis position has on ankle biomechanics. The purpose of the current study is to establish this effect on sagittal plane ankle biomechanics. Methods: A study was performed utilizing a three-dimensional, validated, computational model of the lower extremity. A subtalar arthrodesis was simulated from 20 degrees of varus to 20 degrees of valgus. For each of these subtalar arthrodesis positions, the ankle dorsiflexor and plantarflexor muscles’ fiber force, moment arm, and moments were calculated throughout a physiologic range of motion. Results: Throughout ankle range of motion, plantarflexion and dorsiflexion strength varies with subtalar arthrodesis position. When the ankle joint is in neutral position, plantarflexion strength is maximized in 10 degrees of subtalar valgus and strength varies by a maximum of 2.6% from the peak 221 Nm. In a similar manner, with the ankle joint in neutral position, dorsiflexion strength is maximized with a subtalar joint arthrodesis in 5 degrees of valgus and strength varies by a maximum of 7.5% from the peak 46.8 Nm. The change in strength is due to affected muscle fiber force generating capacities and muscle moment arms. Conclusion: The clinical significance of this study is that subtalar arthrodesis in a position of 5–10 degrees subtalar valgus has biomechanical advantage. This supports previous clinical outcome studies and offers biomechanical rationale for their generally favorable outcomes.

Lower Extremity Biomechanical Demands During Saut de Chat Leaps

2016 ◽  
Vol 31 (4) ◽  
pp. 211-217 ◽  
Author(s):  
Danielle N Jarvis ◽  
Kornelia Kulig
Keyword(s):  
Lower Extremity ◽  
Sagittal Plane ◽  
Reaction Force ◽  
Three Dimensional ◽  
Vertical Force ◽  
Dance Training ◽  
Chronic Injuries ◽  
Analysis System ◽  
Kinetics Of ◽  
Kinematics And Kinetics

In dance, high demands are placed on the lower extremity joints during jumping tasks. The purpose of this study was to compare biomechanical demands placed on the lower extremity joints during the takeoff and landing phases of saut de chat leaps. METHODS: Thirty healthy, experienced dancers with 20.8±4.9 yrs of dance training performed 5 saut de chat leaps. A three-dimensional motion analysis system and force plates were used to collect kinematic and kinetic data. Ground reaction force (GRF) peaks and impulse and sagittal plane kinematics and kinetics of the hip, knee, ankle, and metatarsophalangeal (MTP) joints were calculated for the takeoff and landing phases of each leap. RESULTS: Saut de chat takeoffs demonstrated greater braking GRF impulse (p<0.001), while landings demonstrated greater peak vertical GRF (p<0.001). During takeoff, greater kinetic demands were placed on the MTP (p<0.001) and ankle (p<0.001) joints, while during landing greater kinetic demands were placed on the hip (p=0.037) joint. CONCLUSIONS: Both the takeoff and landing phases of saut de chat leaps place significant demands on a dancer’s body. Takeoff involves greater demands on the more distal joints and requires more braking forces, while the landing phase involves greater demands on the more proximal joints of the lower extremity and requires the dancer to absorb more vertical force. These demands, combined with extensive repetition of movements during training, may contribute to the high number of chronic injuries seen in dance.

Heeled Shoes Increase Knee Work Demand During Repeated Hopping in Dancers

2018 ◽  
Vol 33 (4) ◽  
pp. 243-250
Author(s):  
Pamela Mikkelsen ◽  
Daneille N Jarvis ◽  
Kornelia Kulig
Keyword(s):  
Lower Extremity ◽  
Sagittal Plane ◽  
Joint Work ◽  
Injury Rates ◽  
Work Demand ◽  
Dance Training ◽  
Significant Difference ◽  
Healthy Female ◽  
Percent Contribution ◽  
Work Done

AIMS: Dancers have high injury rates of the lower extremity. External factors such as footwear likely alter the work demands placed on the lower extremity joints when performing dance-style movements. Research on pedestrians shows an increase in knee work demand when wearing heels, which may occur in dancers as well. The purpose of this study was to assess the effect of heeled shoes on lower extremity joint work demand during a basic dance-specific jump (sauté) in dancers when compared to barefoot. METHODS: Ten healthy, female dancers (age 25.6±4.7 yrs; height 1.7±0.1 m; weight 64.9±9.2 kg; mean years of dance training 17.6±6.4) performed repetitive vertical bipedal dance jumps (sautés) barefoot as well as wearing heeled dance shoes. Sagittal plane hip, knee, and ankle kinetics were calculated. Percentages of work done by these joints were calculated in comparison to the work done by the leg as a whole and compared between the two conditions. RESULTS: During a dance-specific jump, the percent contribution of energy absorption was significantly different at the ankle and knee between the two conditions. The ankle contribution decreased from 50.7±6.1% in the bare condition to 34.9±5.3% in the shod condition (p=0.002), and the knee contribution increased from 38.6±3.9% barefoot to 55.1±2.8% shod (p=0.002). The same pattern was seen for energy generation, with the ankle contribution decreasing from 48.1±7.3% to 35.6±6.9% and the knee contribution increasing from 43.3±5.6% to 56.4±6.1% in the bare vs shod condition (both p=0.002). There was no significant difference in the percent contribution from the hip. CONCLUSION: With heeled shoes, there is a shift in work demand from the ankle to the knee with no change at the hip as compared to barefoot.

scholarly journals Contribution of Lower Extremity Joints on Energy Absorption during Soft Landing

2021 ◽  
Vol 18 (10) ◽  
pp. 5130
Author(s):  
Akihiro Tamura ◽  
Kiyokazu Akasaka ◽  
Takahiro Otsudo
Keyword(s):  
Lower Extremity ◽  
Energy Absorption ◽  
Sagittal Plane ◽  
Three Dimensional ◽  
Mechanical Work ◽  
Knee Extensors ◽  
Soft Landing ◽  
Lower Extremity Injuries ◽  
Negative Effect ◽  
Extremity Injuries

Soft landing after jumping is associated with the prevention of lower extremity injuries during sports activities in terms of the energy absorption mechanisms. In this study, the contribution of lower extremity joints during soft landing was investigated. Subjects comprised 20 healthy females. Kinetics and kinematics data were obtained during drop vertical jumps using a three-dimensional motion analysis system. Negative mechanical work values in the lower extremity joints were calculated during landing. A multiple regression analysis was performed to determine which lower extremity joints contributed more in achieving soft landing. The means of mechanical work of the hip, knee, and ankle in the sagittal plane were −0.30 ± 0.17, −0.62 ± 0.31, and −1.03 ± 0.22 J/kg, respectively. Results showed that negative mechanical work in the hip and knee is effective in achieving soft landing. These findings indicate that energy absorption in the hip and knee joints might be an important factor in achieving soft landing, whereas that in the ankle has a negative effect. Therefore, when improving soft landing techniques, we should consider energy absorption in the hip and knee via eccentric activation of the hip and knee extensors during landing.

Adaptations for Controlled Hand Movements in Duchenne’s Muscular Dystrophy

2003 ◽  
Author(s):  
Roscoe C. Bowen ◽  
Rami Seliktar ◽  
Tariq Rahman ◽  
Michael Alexander ◽  
Mena Scavina
Keyword(s):  
Muscular Dystrophy ◽  
Velocity Profile ◽  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Acceleration And Deceleration ◽  
Robotic Orthosis ◽  
The Individual ◽  
Duchenne's Muscular Dystrophy ◽  
Three Dimensional Space

A number of neuropathologies such as Duchenne’s muscular dystrophy (DMD), cause disability in the upper extremity due to the loss of muscle strength. This will eventually prevent the individual from moving their arms in three-dimensional space so it has been proposed that a robotic orthosis could support and augment movement. This orthosis would need to accommodate the movement capabilities of the user. To accomplish this, knowledge of how movements are formed and controlled in the presence of neuromuscular disease needs to be determined. While the arm was supported in a floatation device, DMD subjects were asked to make pointing movements to several targets in the transverse plane. This was done from two start positions while torso movement was constrained and unconstrained. The hand trajectories formed while the torso was constrained were essentially straight but at a cost to the uni-modality of the hand velocity profile. In this configuration the velocity profile contains several phases of acceleration and deceleration producing a multi-modal profile. However, the additional degrees of freedom introduced in the unconstrained torso configuration were employed is such a manner as to produce a smooth uni-modal hand velocity profile.

Novel single marker approach to estimation of lower extremity movement

2017 ◽  
Vol 231 (8) ◽  
pp. 705-714
Author(s):  
Fateme Navvab Motlagh ◽  
Ahmad Reza Arshi
Keyword(s):  
Lower Extremity ◽  
Healthy Subjects ◽  
Walking Speed ◽  
Sagittal Plane ◽  
Three Dimensional ◽  
Coefficient Of Determination ◽  
Heel Strike ◽  
Anatomical Landmarks ◽  
Normal Walking ◽  
Single Marker

Sacrum motion is used extensively in studying the biomechanical characteristics of walking. This study aimed at investigating the potential of sacrum motion to provide an estimation of important gait events in conjunction with predicting the motion of lower extremity segments. Three-dimensional trajectories of 37 reflective markers placed on anatomical landmarks of 14 healthy subjects were recorded while walking at self-selected normal walking speed on treadmill. Elevation angles of lower extremity segments in sagittal plane were estimated using the lower extremity markers. Regression analysis was used to estimate the ability of sacrum kinematic variables to predict lower extremity elevation angles. Prediction was performed at 10 different gait events extracted from three-dimensional sacrum trajectories. The coefficients of the predicting variables were analyzed at these events. The results indicated that heel strike and toe off event instances identified using trajectory of sacrum marker were close to the results of accurate kinematic methods. Additionally, the motion of this point was able to predict lower extremity angles with a suitable coefficient of determination at early single support and mid-swing events. A range of musculoskeletal disorders could be identified using the elevation angles at these events. This study could be considered as a step toward development of effective and simplified instrumentation in clinical diagnosis of gait disorders.

scholarly journals Biomechanical Characteristics on the Lower Extremity of Three Typical Yoga Manoeuvres

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Elizabeth Whissell ◽  
Lin Wang ◽  
Pan Li ◽  
Jing Xian Li ◽  
Zhen Wei
Keyword(s):  
Knee Joint ◽  
Lower Extremity ◽  
Hip Joint ◽  
Sagittal Plane ◽  
Knee Injuries ◽  
Three Dimensional ◽  
Knee Extensor ◽  
Frontal Plane ◽  
Significant Difference ◽  
Angular Impulse

This study was aimed at exploring the biomechanical characteristics of the lower extremity amongst three typical yoga manoeuvres. A total of thirteen experienced female yoga practitioners were recruited in the current study; they were all certified with the Yoga Alliance. A three-dimensional motion capture system with 10 cameras combined with four synchronised force plates was used to collect kinematics of the lower extremity and ground reactive force whilst the participants performed the crescent lunge pose, warrior II pose, and triangle pose. One-way repeated ANOVA was used in exploring the differences amongst the three yoga movements, and the significance was set to alpha < 0.05 . The triangle pose performed the largest range of motion (ROM) of the hip ( 90.5 ° ± 22.9 ° ), knee ( 68.8 ° ± 23.1 ° ), and ankle ( 46.4 ° ± 11.3 ° ) in the sagittal plane and the hip ( 54.8 ° ± 6.5 ° ), knee ( 42.4 ° ± 12.8 ° ), and ankle ( 4.8 ° ± 1.7 ° ) in the frontal plane amongst the three manoeuvres ( P < 0.05 ). No significant difference was found for the hip and ankle joint moment amongst the three manoeuvres ( P > 0.05 ). Knee joint travelled into 9.5° of extension and slight adduction of 1.94° whilst expressing the largest knee joint adduction moments ( 0.30 ± 0.22   Nm / kg ) in the triangle pose. The distribution of the angular impulse of the lower limb joints indicated that the hip joint contributed significantly the most in the sagittal and frontal planes of the three yoga manoeuvres ( P < 0.05 ), ranging from 51.67% to 70.56%. Results indicated that triangle pose may be superior to the other two manoeuvres, which improved hip joint ROM, strength, and dynamic stability. However, knee injuries such as osteoarthritis (OA) should be considered because of the large knee extensor angle and adductor moments.

scholarly journals Sagittal Plane Gait Kinematics in Individuals With Chronic Ankle Instability

2016 ◽  
Vol 21 (5) ◽  
pp. 28-35 ◽  
Author(s):  
Matthew C. Hoch ◽  
David R. Mullineaux ◽  
Kyoungkyu Jeon ◽  
Patrick O. McKeon
Keyword(s):  
Lower Extremity ◽  
Sagittal Plane ◽  
Ankle Instability ◽  
Three Dimensional ◽  
Chronic Ankle Instability ◽  
Initial Contact ◽  
Healthy Individuals ◽  
Gait Kinematics ◽  
Ankle Kinematics ◽  
Absorption Phase

Single joint kinematic alterations have been identified during gait in those with chronic ankle instability (CAI). The purpose of this study was to compare sagittal plane hip, knee, and ankle kinematics during walking in participants with and without CAI. Twelve individuals with CAI and 12 healthy individuals walked on a treadmill at 1.5 m/s. Three-dimensional kinematics were analyzed using mean ensemble curves and independent t tests. Participants with CAI demonstrated less lower extremity flexion during the absorption phase of stance and the limb placement phase of swing, which may have implications for limb placement at initial contact.

Semi-automated methods for 3-D reconstruction of macromolecular complexes

1995 ◽  
Vol 53 ◽  
pp. 42-43
Author(s):  
B. Carragher ◽  
M. Whittaker
Keyword(s):  
Three Dimensional ◽  
Time Saving ◽  
Macromolecular Complexes ◽  
Symmetry Properties ◽  
Dimensional Reconstruction ◽  
Experienced Operator ◽  
Projection Images ◽  
The Individual ◽  
Natural Symmetry

Techniques for three-dimensional reconstruction of macromolecular complexes from electron micrographs have been successfully used for many years. These include methods which take advantage of the natural symmetry properties of the structure (for example helical or icosahedral) as well as those that use single axis or other tilting geometries to reconstruct from a set of projection images. These techniques have traditionally relied on a very experienced operator to manually perform the often numerous and time consuming steps required to obtain the final reconstruction. While the guidance and oversight of an experienced and critical operator will always be an essential component of these techniques, recent advances in computer technology, microprocessor controlled microscopes and the availability of high quality CCD cameras have provided the means to automate many of the individual steps.During the acquisition of data automation provides benefits not only in terms of convenience and time saving but also in circumstances where manual procedures limit the quality of the final reconstruction.

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