Walking Biomechanics Research Articles

Effects of ankle-foot orthoses on mediolateral foot-placement ability during post-stroke gait.

Accurate and precise mediolateral foot placement is important for balance during gait, but is impaired post stroke. Mediolateral foot placement may be improved with ankle-foot orthosis use. The purpose of this study was to determine whether an ankle-foot orthosis improves mediolateral foot-placement ability during post-stroke ambulation. Crossover trial with randomized order of conditions tested. The accuracy and precision of mediolateral foot placement was quantified while subjects targeted four different randomized step widths. Subjects were tested with and without their regular non-rigid ankle-foot orthosis in two separate visits (order randomized). While ankle-foot orthosis use corrected foot and ankle alignment (i.e. significantly decreased mid-swing plantar flexion, p = 0.000), effects of ankle-foot orthosis use on hip hiking (p = 0.545), circumduction (p = 0.179), coronal plane hip range of motion (p = 0.06), and mediolateral foot-placement ability (p = 0.537) were not significant. While ankle-foot orthosis-mediated equinovarus correction of the affected foot and ankle was not associated with improved biomechanics of walking (i.e. proximal ipsilateral hip kinematics or mediolateral foot-placement ability), it may affect other aspects of balance that were not tested in this study (e.g. proprioception, cerebellar, vestibular, and cognitive mechanisms). Studies that investigate the effect of ankle-foot orthosis on gait can help advance stroke rehabilitation by documenting the specific gait benefits of ankle-foot orthosis use. In this study, we investigated the effect of ankle-foot orthosis use on mediolateral foot-placement ability, an aspect of gait important for maintaining balance.

Rocker shoes reduce Achilles tendon load in running and walking in patients with chronic Achilles tendinopathy

Relative rest and pain relief play an important role in the management of Achilles tendinopathy, and might be achieved by reducing the load on the Achilles tendon. Previous studies have provided evidence that rocker shoes are able to decrease the ankle internal plantar flexion moment in healthy runners during walking and running. Since plantar flexion moment is related to the Achilles tendon loading, rocker shoes might be considered in the conservative management of Achilles tendinopathy. Therefore, the aim of this study was to investigate the biomechanics of running and walking in a group of patients with Achilles tendinopathy wearing standard shoes versus rocker shoes. Cross-over. Thirteen Achilles tendinopathy patients (mean age 48 ± 14.5 years) underwent three-dimensional gait analysis wearing standard running shoes and rocker shoes during running and walking. Surface electromyography of triceps surae and tibialis anterior was recorded simultaneously. Patients had symptoms for an average of 22.5 months (median 11.5 months) and VISA-A scores were 54 ± 16. With the rocker shoes, the peak plantar flexion moment was reduced by 13% in both running (0.28 N m/kg, p<0.001) and walking (0.20 N m/kg, p<0.001). The peak activity of tibialis anterior was increased by 35% (p=0.015) for the rocker shoes in walking. There was no difference between electromyography peak amplitudes of triceps surae between two shoe sessions in both activities. When used by patients with chronic Achilles tendinopathy, rocker shoes cause a significant reduction in plantar flexion moment in the late stance phase of running and walking without substantial adaptations in triceps surae muscular activity.

Visual control of foot placement when walking over complex terrain.

The aim of this study was to investigate the role of visual information in the control of walking over complex terrain with irregularly spaced obstacles. We developed an experimental paradigm to measure how far along the future path people need to see in order to maintain forward progress and avoid stepping on obstacles. Participants walked over an array of randomly distributed virtual obstacles that were projected onto the floor by an LCD projector while their movements were tracked by a full-body motion capture system. Walking behavior in a full-vision control condition was compared with behavior in a number of other visibility conditions in which obstacles did not appear until they fell within a window of visibility centered on the moving observer. Collisions with obstacles were more frequent and, for some participants, walking speed was slower when the visibility window constrained vision to less than two step lengths ahead. When window sizes were greater than two step lengths, the frequency of collisions and walking speed were weakly affected or unaffected. We conclude that visual information from at least two step lengths ahead is needed to guide foot placement when walking over complex terrain. When placed in the context of recent research on the biomechanics of walking, the findings suggest that two step lengths of visual information may be needed because it allows walkers to exploit the passive mechanical forces inherent to bipedal locomotion, thereby avoiding obstacles while maximizing energetic efficiency.

Normal biomechanical values of walking for healthy Saudi children in Riyadh city

The study of Biomechanics of walking provides us with reference data needed to distinguish between normal and abnormal walking. The purpose of this study was to determine the normal values of some walking biomechanical variables of Saudi Arabian children between the ages of 7 and 11 years. The present study was also aimed at exploring the differences between age groups in walking biomechanical variables. The study sample consisted of 50 healthy Saudi children without any structural deformities and with a body mass index (BMI) of less than overweight (BMI <20). Before collecting data, reflective markers were attached to joints of the right side in order to help in digitizing and locating three-dimensional coordinates using Motus 8 program. Then, subjects walked on a raised walkway with an AMTI force plate (500 Hz) in its middle and filmed by two cameras (50 Hz) one to the right side and the other to the backside of the subject. Results indicated that there were no significant differences in kinematic variables between groups except in stride and step lengths. In addition, there were no significant differences in kinetic variables between groups except in push of force (Y1). Results also indicated a strong relationship between walking velocity and most of the kinematic variables and the three peaks of vertical force. In conclusion, the results of this study showed clear differences between Saudi children and children of other countries. It is recommended that the values of this study be used as normal values for evaluation of walking of Saudi children between the ages 7 and 11.

Effects of obesity on lower extremity muscle function during walking at two speeds

Walking is a recommended form of physical activity for obese adults, yet the effects of obesity and walking speed on the biomechanics of walking are not well understood. The purpose of this study was to examine joint kinematics, muscle force requirements and individual muscle contributions to the walking ground reaction forces (GRFs) at two speeds (1.25ms−1 and 1.50ms−1) in obese and nonobese adults. Vasti (VAS), gluteus medius (GMED), gastrocnemius (GAST), and soleus (SOL) forces and their contributions to the GRFs were estimated using three-dimensional musculoskeletal models scaled to the anthropometrics of nine obese (35.0 (3.78kgm−2)); body mass index mean (SD)) and 10 nonobese (22.1 (1.02kgm−2)) subjects. The obese individuals walked with a straighter knee in early stance at the faster speed and greater pelvic obliquity during single limb support at both speeds. Absolute force requirements were generally greater in obese vs. nonobese adults, the main exception being VAS, which was similar between groups. At both speeds, lean mass (LM) normalized force output for GMED was greater in the obese group. Obese individuals appear to adopt a gait pattern that reduces VAS force output, especially at speeds greater than their preferred walking velocity. Greater relative GMED force requirements in obese individuals may contribute to altered kinematics and increased risk of musculoskeletal injury/pathology. Our results suggest that obese individuals may have relative weakness of the VAS and hip abductor muscles, specifically GMED, which may act to increase their risk of musculoskeletal injury/pathology during walking, and therefore may benefit from targeted muscle strengthening.

Influence of ankle plantar flexor muscle architecture and strength on gait in boys with haemophilia in comparison to typically developing children

Altered gait patterns, muscle weakness and atrophy have been reported in young boys with severe haemophilia when compared to unaffected peers. The aim of this study was to determine whether lateral gastrocnemius muscle size and architecture influenced biomechanical walking patterns of boys with haemophilia and if these relationships differed from age-matched typically developing boys. Biomechanical function of the knee and ankle during level walking, lateral gastrocnemius anatomical cross-sectional area, thickness, width, fascicle length and pennation angle and ankle plantar flexor muscle strength were recorded in 19 typically developing boys aged 7-12years and 19 age-matched haemophilic boys with a history of ankle joint bleeding. Associations between gait, strength and architecture were compared using correlations of peak gait values. Haemophilic boys walked with significantly larger (P<0.05) ankle dorsi flexion angles and knee flexion moments. The ankle plantar flexor muscles of haemophilic boys were significantly weaker and smaller when compared to typically developing peers. In the typically developing boys there was no apparent association between muscle architecture, strength and walking patterns. In haemophilic boys maximum muscle strength and ACSA normalized torque of the ankle plantar flexors together with the muscle width, thickness, fascicle length and angulation (P<0.05) were associated with motion at the ankle and peak moments at the knee joint. Muscle strength deficits of the ankle plantar flexors and changes in muscle size and architecture may underpin the key biomechanical alterations in walking patterns of haemophilic boys with a history of ankle joint bleeding.

Biomechanics of slow running and walking with a rocker shoe

Evidence suggests a link between the loading of the Achilles tendon and the magnitude of the ankle internal plantar flexion moment during late stance of gait, which is clinically relevant in the management of Achilles tendinopathy. Some studies showed that rocker shoes can reduce the ankle internal plantar flexion moment. However, the existing evidence is not conclusive and focused on walking and scarce in running. Sixteen healthy runners participated in this study. Lower extremity kinetics, kinematics and electromyographic (EMG) signals of triceps surae and tibialis anterior were quantified for two types of shoes during running and walking. The peak ankle plantar flexion moment was reduced significantly in late stance of running (0.27Nm/kg; p<0.001) and walking (0.24Nm/kg; p<0.001) with the rocker shoe compared to standard shoe. The ankle power generation and plantar flexion moment impulse were also reduced significantly when running and walking with the rocker shoe (p<0.001). No significant changes in the knee and hip moments were found in running and walking. A significant delay of the EMG peak, approximately 2% (p<0.001), was present in the triceps surae when walking with rocker shoes. There were no significant changes in the EMG peak amplitude of triceps surae in running and walking. The peak amplitude of tibialis anterior was significantly increased (64.7μV, p<0.001) when walking with rocker shoes. The findings show that rocker shoes reduce the ankle plantar flexion moment during the late stance phase of running and walking in healthy people.

Effect of sports shoes on children's vertical jump performance and midfoot and ankle kinetics

Shoes considerably alter the walking and running biomechanics of children (Wegener et al. 2011). However few studies have investigated the effect of shoes on children's physical performance. Tazuke...

A Novel Experimental Knee-Pain Model Affects Perceived Pain and Movement Biomechanics

Knee injuries are prevalent, and the associated knee pain is linked to disability. The influence of knee pain on movement biomechanics, independent of other factors related to knee injuries, is difficult to study and unclear. (1) To evaluate a novel experimental knee-pain model and (2) better understand the independent effects of knee pain on walking and running biomechanics. Crossover study. Biomechanics laboratory. Twelve able-bodied volunteers (age = 23 ± 3 years, height = 1.73 ± 0.09 m, mass = 75 ± 14 kg). Participants walked and ran at 3 time intervals (preinfusion, infusion, and postinfusion) for 3 experimental conditions (control, sham, and pain). During the infusion time interval for the pain and sham conditions, hypertonic or isotonic saline, respectively, was continuously infused into the right infrapatellar fat pad for 22 minutes. We used repeated-measures analyses of variance to evaluate the effects of time and condition on (1) perceived knee pain and (2) key biomechanical characteristics (ground reaction forces, and joint kinematics and kinetics) of walking and running (P < .05). The hypertonic saline infusion (1) increased perceived knee pain throughout the infusion and (2) reduced discrete characteristics of each component of the walking ground reaction force, walking peak plantar-flexion angle (range = 62°-67°), walking peak plantar-flexion moment (range = 95-104 N·m), walking peak knee-extension moment (range = 36-49 N·m), walking peak hip-abduction moment (range = 62-73 N·m), walking peak support moment (range = 178-207 N·m), running peak plantar-flexion angle (range = 38°-77°), and running peak hip-adduction angle (range = 5-21°). This novel experimental knee pain model consistently increased perceived pain during various human movements and produced altered running and walking biomechanics that may cause abnormal knee joint-loading patterns.

Biomechanics and energetics of walking on uneven terrain

Walking on uneven terrain is more energetically costly than walking on smooth ground, but the biomechanical factors that contribute to this increase are unknown. To identify possible factors, we constructed an uneven terrain treadmill that allowed us to record biomechanical, electromyographic and metabolic energetics data from human subjects. We hypothesized that walking on uneven terrain would increase step width and length variability, joint mechanical work and muscle co-activation compared with walking on smooth terrain. We tested healthy subjects (N=11) walking at 1.0 m s(-1), and found that, when walking on uneven terrain with up to 2.5 cm variation, subjects decreased their step length by 4% and did not significantly change their step width, while both step length and width variability increased significantly (22 and 36%, respectively; P<0.05). Uneven terrain walking caused a 28 and 62% increase in positive knee and hip work, respectively, and a 26% greater magnitude of negative knee work (0.0106, 0.1078 and 0.0425 J kg(-1), respectively; P<0.05). Mean muscle activity increased in seven muscles in the lower leg and thigh (P<0.05). These changes caused overall net metabolic energy expenditure to increase by 0.73 W kg(-1) (28%; P<0.0001). Much of that increase could be explained by the increased mechanical work observed at the knee and hip. Greater muscle co-activation could also contribute to increased energetic cost but to unknown degree. The findings provide insight into how lower limb muscles are used differently for natural terrain compared with laboratory conditions.

Predicting Sagittal Plane Biomechanics That Minimize the Axial Knee Joint Contact Force During Walking

Both development and progression of knee osteoarthritis have been associated with the loading of the knee joint during walking. We are, therefore, interested in developing strategies for changing walking biomechanics to offload the knee joint without resorting to surgery. In this study, simulations of human walking were performed using a 2D bipedal forward dynamics model. A simulation generated by minimizing the metabolic cost of transport (CoT) resembled data measured from normal human walking. Three simulations targeted at minimizing the peak axial knee joint contact force instead of the CoT reduced the peak force by 12-25% and increased the CoT by 11-14%. The strategies used by the simulations were (1) reduction in gastrocnemius muscle force, (2) avoidance of knee flexion during stance, and (3) reduced stride length. Reduced gastrocnemius force resulted from a combination of changes in activation and changes in the gastrocnemius contractile component kinematics. The simulations that reduced the peak contact force avoided flexing the knee during stance when knee motion was unrestricted and adopted a shorter stride length when the simulated knee motion was penalized if it deviated from the measured human knee motion. A higher metabolic cost in an offloading gait would be detrimental for covering a long distance without fatigue but beneficial for exercise and weight loss. The predicted changes in the peak axial knee joint contact force from the simulations were consistent with estimates of the joint contact force in a human subject who emulated the predicted kinematics. The results demonstrate the potential of using muscle-actuated forward dynamics simulations to predict novel joint offloading interventions.

A preliminary investigation of powered prostheses for improved walking biomechanics in bilateral transfemoral amputees.

The authors conducted a preliminary investigation of the extent to which a pair of powered prostheses can provide improved gait biomechanics in bilateral transfemoral amputee walking. Specifically, a finite state-based impedance controller for level ground walking was implemented in a pair of powered knee and ankle prostheses. The efficacy of the powered prostheses and impedance-based controllers was tested on a healthy subject using able-body adapters. Motion capture data was collected while the subject performed treadmill walking with the powered prostheses. This kinematic data is compared to that of healthy subjects, and also to previously published data for bilateral transfemoral amputee gait with passive prostheses. The comparison indicates that the powered prostheses are able to provide a walking gait that is considerably more representative of healthy biomechanical gait relative to passive prostheses.

Locomotion Mechanics in Obese Adults and Children

Obese individuals are advised to engage in daily physical activity to improve health and manage body weight. Walking is the most popular form of physical activity, yet the effects of obesity on the biomechanics of walking are still being discovered. In this review, I highlight recent research that has found that childhood and adult obesity are associated with slower level walking speeds, wider steps, and greater loads across lower extremity joints. Given the likely increase in risk of musculoskeletal injury/pathology in obese individuals, clinicians should use caution when recommending brisk walking as a form of physical activity. I also address how improvements in our ability to measure and model musculoskeletal actions as well as further cross-sectional and longitudinal studies will enhance our understanding of how obesity affects our ability to perform essential locomotor tasks.

Walking with coffee: Why does it spill?

In our busy lives, almost all of us have to walk with a cup of coffee. While often we spill the drink, this familiar phenomenon has never been explored systematically. Here we report on the results of an experimental study of the conditions under which coffee spills for various walking speeds and initial liquid levels in the cup. These observations are analyzed from the dynamical systems and fluid mechanics viewpoints as well as with the help of a model developed here. Particularities of the common cup sizes, the coffee properties, and the biomechanics of walking proved to be responsible for the spilling phenomenon. The studied problem represents an example of the interplay between the complex motion of a cup, due to the biomechanics of a walking individual, and the low-viscosity-liquid dynamics in it.

Gait Differs Between Unilateral and Bilateral Knee Osteoarthritis

Creaby MW, Bennell KL, Hunt MA. Gait differs between unilateral and bilateral knee osteoarthritis. ObjectivesTo compare walking biomechanics in the most painful leg, and symmetry in biomechanics between legs, in individuals with (1) unilateral pain and structural osteoarthritis (OA), (2) unilateral pain, but bilateral structural OA, and (3) bilateral pain and structural OA and in (4) an asymptomatic control group. DesignCohort study. SettingLaboratory based. ParticipantsParticipants with symptomatic and/or radiographic medial tibiofemoral OA in one or both knees (n=91), and asymptomatic control participants (n=31). InterventionsNot applicable. Main Outcome MeasureThe peak knee adduction moment, peak knee flexion moment, knee varus-valgus angle, peak knee flexion angle, toe-out, and trunk lean were computed from 3-dimensional analysis of walking at a self-selected speed. ResultsAfter controlling for walking speed, greater trunk lean toward the more painful knee and reduced flexion in the more painful knee were observed in all OA groups compared with the control group. Between-knee asymmetries indicating greater varus angle and a lower external flexion moment in the painful knee were present in those with unilateral pain and either unilateral or bilateral structural OA. Knee biomechanics were symmetrical in those with bilateral pain and structural OA and in the pain free control group. ConclusionsThe presence of pain unilaterally appears to be associated with asymmetries in knee biomechanics. Contrary to this, bilateral pain is associated with symmetry. This suggests that the symptomatic status of both knees should be considered when contemplating unilateral or bilateral biomechanical interventions for medial knee OA.

Biomechanics of walking with snowshoes

Snowshoeing is a popular form of winter recreation due to the development of lightweight snowshoes that provide flotation, traction, and stability. The purpose of this study was to determine the effects of snowshoes on lower extremity kinematics during level walking. Twelve adults (6 males, 6 females, body mass = 67.5 ± 10.7 kg) completed six 3-minute level walking trials. Subjects walked overground without snowshoes and on packed snow using conventional and flexible tail snowshoes. We placed lightweight inertial/gyroscopic sensors on the sacrum, thigh, shank, and foot. We recorded sensor orientation and calculated hip, knee, and ankle joint angles and angular velocities. Compared to level overground walking, subjects had greater hip and knee flexion during stance and greater hip flexion during swing while snowshoeing. Ankle plantarflexion began during late swing when snowshoeing vs. heel strike during overground walking. Lower extremity kinematics were similar across snowshoe frame designs during level walking. Our results show that snowshoeing on packed snow results in a more flexed leg compared to overground walking and may reflect a strategy to limit the effects of walking with an extended heel.

Functional and Biomechanical Outcomes After Using Biofeedback for Retraining Symmetrical Movement Patterns After Total Knee Arthroplasty: A Case Report

Case report. Rehabilitation that includes progressive quadriceps strengthening after total knee arthroplasty (TKA) leads to superior outcomes. Though patients with TKA show marked functional improvement after outpatient physical therapy, they continue to adopt movement asymmetries characterized by reduced knee excursion on the operated limb and excessive loading on the contralateral limb. The purpose of this case report was to describe the functional and biomechanical improvements in a patient who, after TKA, participated in a novel physical therapy protocol that included retraining of symmetrical movement patterns. A 57-year-old female with unilateral knee osteoarthritis was evaluated prior to TKA and at 3 and 10 weeks after surgery. Postoperative rehabilitation included progressive quadriceps strengthening and movement retraining that consisted of visual, verbal, and tactile feedback to promote symmetrical weight bearing during strengthening exercises and functional activities. Outcomes were compared to a historical cohort of patients with TKA. Prior to TKA, the patient scored below average on all functional measures and walked with knee biomechanics that were abnormal and asymmetrical. After symmetry retraining, her knee motion and moments were restored to normal levels. The patient also walked with greater magnitude and more symmetrical knee excursion compared to a cohort of similar patients. This case report describes the use of a novel rehabilitation protocol intended to improve walking biomechanics and functional outcomes after TKA. Restoration of symmetrical movement patterns could improve long-term outcomes of TKA. Further research is needed to evaluate the effectiveness and implementation of similar rehabilitation strategies in a wide range of patients after TKA. Therapy, level 4.

Energetics and Biomechanics of Inclined Treadmill Walking in Obese Adults

Brisk walking is a recommended form of exercise for obese individuals. However, lower-extremity joint loads and the associated risk of musculoskeletal injury or pathological disease increase with walking speed. Walking uphill at a slower speed is an alternative form of moderate intensity exercise that may reduce joint loading. The purpose of this study was to quantify the energetics and biomechanics of level and uphill walking in obese adults. We hypothesized that compared to brisk level walking, walking slower up a moderate incline would reduce lower-extremity net muscle moments while providing appropriate cardiovascular stimulus. Twelve obese adult volunteers, with mass of 100.5±15.7 kg and body mass index of 33.4±2.6 kg·m (mean±SD), participated in this study. We measured oxygen consumption, ground reaction forces, and three-dimensional lower-extremity kinematics while subjects walked on a dual-belt force-measuring treadmill at several speed (0.50-1.75 m·s) and grade (0°-9°) combinations. We calculated metabolic rate, loading rates, and net muscle moments at the hip, knee, and ankle for each condition. Metabolic rates were similar across trials and were of moderate intensity (48.5%-59.8% of VO2max). Walking slower uphill significantly reduced loading rates and lower-extremity net muscle moments compared with faster level walking. Peak knee extension and adduction moments were reduced by ∼19% and 26%, respectively, when subjects walked up a 6° incline at 0.75 m·s versus level walking at 1.50 m·s. These results suggest that walking at a relatively slow speed up a moderate incline is a potential exercise strategy that may reduce the risk of musculoskeletal injury/pathological disease while providing proper cardiovascular stimulus in obese adults.

Comfort and stability ratings of different shoe lacing patterns depend on the runners’ level of performance

INTRODUCTION Recent studies have shown the influence of shoe lacing on the biomechanics of walking (Fiedler et al., 2011) and running (Hagen and Hennig 2009; Hong et al., 2011). With his choice of lacing tightness, number of laced eyelets, and special lacing techniques a runner is able to adjust the shoe’s upper to his individual foot morphology and, therefore, to optimize shoe fit (Hagen et al., 2010). It is also well known that most competitive runners choose very tight lacing to avoid movement of the foot within the shoe. The most common running shoes are provided with six straight eyelets in line. Many running shoes are also featured with a higher seventh eyelet that is slightly shifted to the lateral side. Most runners, however, do not use this additional seventh eyelet. Although the above mentioned laboratory studies revealed the positive effects of higher lacings, it is questionable whether the use of seven-eyelet techniques is practicable.

IMU-based ambulatory walking speed estimation in constrained treadmill and overground walking

This study evaluated the performance of a walking speed estimation system based on using an inertial measurement unit (IMU), a combination of accelerometers and gyroscopes. The walking speed estimation algorithm segments the walking sequence into individual stride cycles (two steps) based on the inverted pendulum-like behaviour of the stance leg during walking and it integrates the angular velocity and linear accelerations of the shank to determine the displacement of each stride. The evaluation was performed in both treadmill and overground walking experiments with various constraints on walking speed, step length and step frequency to provide a relatively comprehensive assessment of the system. Promising results were obtained in providing accurate and consistent walking speed/step length estimation in different walking conditions. An overall percentage root mean squared error (%RMSE) of 4.2 and 4.0% was achieved in treadmill and overground walking experiments, respectively. With an increasing interest in understanding human walking biomechanics, the IMU-based ambulatory system could provide a useful walking speed/step length measurement/control tool for constrained walking studies.