Leg and lower limb dynamic joint stiffness during different walking speeds in healthy adults

Akl, Abdel-Rahman; Baca, Arnold; Richards, Jennifer C.; Conceição, Filipe

doi:10.1016/j.gaitpost.2020.09.023

Cited by 19 publications

(11 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, walking speed affects elements of walking kinematics, ground reaction forces, and muscle activity. The muscle activity is an important mechanism that is required for walking stability, especially at different walking speeds [1]. Hof et al (2002) examined electromyographic (EMG) patterns at a variety of speeds and found considerable changes with speed [2].…”

Section: Introductionmentioning

confidence: 99%

Muscle Co-Activation around the Knee during Different Walking Speeds in Healthy Females

Akl

Gonçalves

Fonseca

et al. 2021

Sensors

Self Cite

View full text Add to dashboard Cite

The purpose of this study was to examine the changes in co-activation around the knee joint during different walking speeds in healthy females using the co-activation index. Ten healthy females (age: 21.20 ± 7.21 years, height: 164.00 ± 4.00 cm, mass: 60.60 ± 4.99 kg) participated in this study and performed three walking speeds (slow, normal, and fast). A Qualisys 11-camera motion analysis system sampling at a frequency of 200 Hz was synchronized with a Trigno EMG Wireless system operating at a 2000 Hz sampling frequency. A significant decrease in the co-activation index of thigh muscles was observed between the slow and fast, and between the normal and fast, walking speeds during all walking phases. A non-significant difference was observed between the slow and normal walking speeds during most walking phases, except the second double support phase, during which the difference was significant. A negative relationship was found between walking speed and the co-activation index of thigh muscles in all speeds during walking phases: first double support (r = −0.3386, p < 0.001), single support (r = −0.2144, p < 0.01), second double support (r = −0.4949, p < 0.001), and Swing (r = −0.1639, p < 0.05). In conclusion, the results indicated high variability of thigh muscle co-activation in healthy females during the different walking speeds, and a decrease in the co-activation of the thigh muscles with the increase of speed.

show abstract

Section: Introductionmentioning

confidence: 99%

Muscle Co-Activation around the Knee during Different Walking Speeds in Healthy Females

Akl

Gonçalves

Fonseca

et al. 2021

Sensors

Self Cite

View full text Add to dashboard Cite

show abstract

“…between rigid-bodies of the shank and rearfoot, with a three-segment foot defined as per the IOR model [ 32 ]. Defining the ankle joint in this way has been shown to provide improved estimation of joint angle changes [ 33 ], which has important implications for the ankle torque–angle relationship, especially compared with previous research that used a single rigid foot segment [ 12 , 19 , 34 , 35 ]. Neutral ankle angle (0°) was defined as the ankle position during quiet standing with plantar flexion defined as positive.…”

Section: Methodsmentioning

confidence: 99%

Walking with increasing acceleration is achieved by tuning ankle torque onset timing and rate of torque development

Wade

Birch

Farris

2022

J. R. Soc. Interface.

View full text Add to dashboard Cite

Understanding the mechanics of torque production about the ankle during accelerative gait is key to designing effective clinical and rehabilitation practices, along with developing functional robotics and wearable assistive technologies. We aimed to explore how torque and work about the ankle is produced as walking acceleration increases from 0 to 100% maximal acceleration. We hypothesized that as acceleration increased, greater work about the ankle would not be solely due to ramping up plantar flexor torque, and instead would be a product of adjustments to relative timing of ankle torque and angular displacement. Fifteen healthy participants performed walking without acceleration (constant speed), as well as low, moderate and maximal accelerations, while motion capture and ground reaction force data were recorded. We employed vector coding in a novel application to overcome limitations of previously employed evaluation methods. As walking acceleration increased, there was reduced negative work and increased positive work about the ankle. Furthermore, early stance dorsiflexion had reducing plantar flexor torque due to delayed plantar flexor torque onset as acceleration increased, while mid-stance ankle plantar flexor torque was substantially increased with minimal ankle dorsiflexion, irrespective of acceleration magnitude. Assistive devices need to account for these changes during accelerative walking to facilitate functional gait.

show abstract

“…In addition, the maximum kneeflexion angle in the shock absorption should be limited to ∆θ max . Abdel et al [24] suggested that ∆θ max should not exceed about 22 • . Finally, to avoid oscillation, the motion of the shockabsorption process should be unidirectional.…”

Section: Optimized Knee-trajectory Modulation 211 Optimized Shock-abs...mentioning

confidence: 99%

“…Although set-A (A1 and A2, with lower F pre and k) contributes to the reduction in the PGRF, it leads to excessive knee flexion angles, (as shown in Figure 7c,d, which may cause the opposite foot to scuff the ground during swings. According to the experience of clinical trials, the variation in knee flexion during shock absorption should not exceed about 22 • [24].…”

Section: Simulation Of the Oktmmentioning

confidence: 99%

Trajectory Modulation for Impact Reducing of Lower-Limb Exoskeletons

et al. 2022

View full text Add to dashboard Cite

Lower-limb exoskeletons have received considerable attention because of their effectiveness in walking assistance and rehabilitation for paraplegic patients. Excessive foot–ground impacts during walking make patients uncomfortable and even lead to injury. In this paper, we propose an optimized knee trajectory modulation (OKTM) for foot–ground impact reduction. The OKTM can reduce the peak of ground reaction force (PGRF) by knee-joint trajectory modulation based on a parameters-optimizing spring-damping system. In addition, a hip trajectory modulation (HTM) is presented to compensate for torso pitch deflections due to the OKTM. Unlike traditional mechanical-device-based methods, the proposed OKTM and HTM require no bulky mechanical structures, and can adaptively adjust parameters to adapt to different impacts. We demonstrated the efficiency of the proposed approach in both simulations and experiments for engineering verifications. Results show that the approach can effectively reduce PGRF.

show abstract

Leg and lower limb dynamic joint stiffness during different walking speeds in healthy adults

Cited by 19 publications

References 48 publications

Muscle Co-Activation around the Knee during Different Walking Speeds in Healthy Females

Muscle Co-Activation around the Knee during Different Walking Speeds in Healthy Females

Walking with increasing acceleration is achieved by tuning ankle torque onset timing and rate of torque development

Trajectory Modulation for Impact Reducing of Lower-Limb Exoskeletons

Contact Info

Product

Resources

About