The influence of heel height on utilized coefficient of friction during walking

Wearing high heel shoes has been associated with an increased potential for slips and falls. The association between wearing high heels and the increased potential for slipping suggests that the friction demand while wearing high heels may be greater when compared to wearing low heel shoes. The purpose of this study was to determine if heel height affects utilized friction (uCOF) during walking. A secondary purpose of this study was to compare kinematics at the ankle, knee, and hip that may explain uCOF differences among shoes with varied heel heights. Fifteen healthy women (mean age 24.5 ± 2.5 yrs) participated. Subjects walked at self-selected velocity under 3 different shoe conditions that varied in heel height (low: 1.27 cm, medium: 6.35 cm, and high: 9.53 cm). Ground reaction forces (GRFs) were recorded using a force platform (1560 Hz). Kinematic data were obtained using an 8 camera motion analysis system (120 Hz). Utilized friction was calculated as the ratio of resultant shear force to vertical force. One-way repeated measures ANOVAs were performed to test for differences in peak uCOF, GRFs at peak uCOF and lower extremity joint angles at peak uCOF. On average, peak uCOF was found to increase with heel height. The increased uCOF observed in high heel shoes was related to an increase in the resultant shear force and decrease in the vertical force. Our results signify the need for proper public education and increased footwear industry awareness of how high heel shoes affect slip risk.     

Comparison of gait with and without shoes in children

Full body gait analysis was used to determine if differences exist in kinematic, kinetic, and temporal-spatial data with and without shoes in able-bodied children. The greatest difference noted between conditions was an increase in stride length with shoes. Minimal changes were seen in kinematics and kinetics with the addition of shoes. Due to the very tight standard deviations of the data, these minimal changes in the magnitude of the curves resulted in statistically significant differences, yet these changes do not appear to be clinically significant. It is believed that this study establishes that barefoot gait analysis is sufficient for most clinical studies, and an additional assessment undertaken while wearing shoes is not necessary.     

A comparison of young children’s spatiotemporal gait measures in three common types of footwear with different sole hardness

BackgroundIt is unknown what the impact of sole hardness is on young children’s gait. Yet, this feature is commonly marketed as having differing benefits for young children’s walking and development.Research questionWhat are the differences in spatiotemporal measures of gait during walking and running in three common types of young children’s footwear with a soft sole, compared to a hard sole?MethodsThe study used a quasi-experimental design, with the condition order randomised using a Latin square sequence. Forty-seven children were recruited (aged 2–4 years). Participants walked or ran the length of a GAITRite mat in a randomized order in a soft (Shore 48–53) or hard soled (Shore 60–65) sneaker, boot and sandal condition. Linear regression analyses were used to investigate the difference between footwear for the different gait parameters including velocity, cadence, step time, swing percentage, stance percentage, double support time and the toe in/out angle.ResultsChildren walked with a shorter stride length in the hard-soled sandals compared to the soft- soled sandals (p < 0.05). There were no other differences in spatiotemporal variables in the soft versus hard soled sandals during walking or running (p > 0.05). There were no differences in any spatiotemporal gait variables during walking or running in soft versus hard- soled runners and no differences in walking or running in soft versus hard-soled boots (p > 0.05).SignificanceThere were few differences in spatiotemporal parameters between soft and hard-soled footwear in both walking and running in three different types of footwear. This may be a positive finding for footwear designers and manufacturers, as a harder sole appeared to have limited impact on spatiotemporal gait parameters.     

Spatial and temporal gait characteristics of elderly individuals during backward and forward walking with shoes and barefoot

Backward walking (BW) is an inherent component of mobility and function in daily activities, particularly indoors, when it is more likely that a person is barefoot. No studies to date have compared the spatio-temporal characteristics of BW with and without shoes in elderly individuals.This study compared spatio-temporal measures of BW and forward walking (FW) among elderly individuals while barefoot or wearing shoes. Forty-seven elderly individuals (13 men and 34 women, 76.7 ± 7.7 years of age) were evaluated. Participants were requested to walk at a comfortable, self-selected pace across the GAITRite^® walkway for three trials under each of four conditions: walking forward (FW) and BW wearing their own comfortable low-heeled walking shoes and FW and BW walking without shoes. Gait speed, stride length and cadence were significantly reduced in BW versus FW, with an increase in double limb support (DLS), both with and without shoes. Barefoot BW resulted in significantly increased gait speed and cadence, and decreased DLS compared to BW with shoes. BW stride length was not affected by footwear. While barefoot FW was also associated with a significant increase in cadence and decrease in DLS time compared to walking with shoes, it decreased stride length and had no detrimental effect on gait speed. Assessment of the spatio-temporal parameters of walking barefoot and with shoes during FW and BW can contribute to our understanding of the ability of elderly individuals to adapt to changing walking conditions, and should be included in the assessment of functional mobility of elderly individuals.     

Changes in muscle activity in children with hemiplegic cerebral palsy while walking with and without ankle-foot orthoses

We compared the electromyographic (EMG) signals of lower extremity muscle groups in 10 children with hemiplegic cerebral palsy (CP) while walking barefoot and in a hinged ankle–foot orthosis (HAFO). All children had excessive plantarflexion and initial toe-contact on the affected side when walking barefoot, a typical gait pattern for hemiplegic patients. The patients walked with a physiological heel–toe gait pattern when wearing the HAFO. The peak activity of the tibialis anterior muscle was reduced by 36.1% at initial contact and loading response phase and by 57.3% just after toe-off when using a HAFO. The decrease in activity was thought to result from the change in gait pattern from a toe-gait to a heel–toe gait as well as the use of a HAFO. The HAFO also slightly decreased muscle activity in the proximal leg muscles mainly during swing phase, improved stride length, decreased cadence, improved walking speed, increased peak hip flexion, improved kinematics in loading response phase at the knee, and reduced the excessive ankle plantarflexion.     

Sagittal subtalar and talocrural joint assessment between barefoot and shod walking: A fluoroscopic study

BackgroundWhile wearing shoes is common in daily activities, most foot kinematic models report results on barefoot conditions. It is difficult to describe foot position inside shoes. This study used fluoroscopic images to determine talocrural and subtalar motion.Research QuestionWhat are the differences in sagittal talocrual and subtalar kinematics between walking barefoot and while wearing athletic walking shoes?MethodsThirteen male subjects (mean age 22.9 ± 2.9 years, mean weight 77.2 ± 6.9 kg, mean height 178.2 ± 3.7 cm) screened for normal gait were tested. A fluoroscopy unit was used to collect images during stance. Sagittal motion of the talocrural and subtalar joints of the right foot were analyzed barefoot and in an athletic walking shoe.ResultsShod talocrural position at heel strike was 6.0° of dorsiflexion and shod peak talocrural plantarflexion was 4.2°. Barefoot talocrural plantarflexion at heel strike was 4.2° and barefoot peak talocrural plantarflexion was 10.9°. Shod subtalar position at heel strike was 2.6° of plantarflexion and peak subtalar dorsiflexion was 1.5°. The barefoot subtalar joint at heel strike was in 0.4° dorsiflexion and barefoot peak subtalar dorsiflexion was 3.5°. As the result of wearing shoes, average walking speed and stride length increased and average cadence decreased. Comparing barefoot to shod walking there was a statistical significance in talocrural dorsiflexion and at heel strike and peak talocrural dorsiflexion, subtalar plantarflexion at heel strike and peak subtalar dorsiflexion, walking speed, stride length, and cadence.SignificanceThis work demonstrates the ability to directly measure talocrural and subtalar kinematics of shod walking using fluoroscopy. Future work using this methodology can be used to increase understanding of hindfoot kinematics during a variety of non-barefoot activities.     

The influence of heel height on lower extremity kinematics and leg muscle activity during gait in young and middle-aged women

The aim of this study was to evaluate the changes in electromyographic (EMG) activity of the lower limb muscles, and hip, knee and ankle kinematics during gait while wearing low- (4-cm) and high-heeled (10-cm) shoes in 31 young and 15 middle-aged adult women. We observed an increase in knee flexion and decrease in ankle eversion associated with elevated heel heights suggesting that compensatory mechanisms attenuating ground reaction forces may be compromised during gait with higher-heeled shoes. Additionally, we observed increased muscle activity during high-heeled gait that may exacerbate muscle fatigue. Collectively, these findings suggest that permanent wearing of heeled footwear could contribute to muscle overuse and repetitive strain injuries.     

Gait and Metabolic Adaptation of Walking with Negative Heel Shoes

The purpose of this study was to explore the gait pattern and metabolic responses of walking with negative heel shoes as compared to walking with normal shoes. Nineteen female subjects were recruited, of whom 13 (aged 23.08 ± 3.9 years, body weight 50.18 ± 5.3 kg, and body height 1.63 ± 0.05 m) participated in the gait pattern study, and 6 (age 32.8 ± 6.6 years, body weight 58.3 ± 5.8 kg, and body height 1.64 ± 0.01 m) in the metabolic study. In the gait pattern study, movement kinematics and kinetic data were obtained by video analysis and force platform measurement during the process of walking at a constant speed of 1.33 m/s on a treadmill and over ground, respectively. In the metabolic study, heart rate and oxygen consumption were monitored during treadmill walking. The results showed that there was a significant difference between walking on a treadmill with negative heel shoes and walking with normal shoes, in terms of stride cycle time, cadence, stride length, and angles of the ankle, knee, and hip joints. Differences also were found with the maximum and minimum ground reaction forces and their occurrence times. Metabolically, heart rate and oxygen consumption showed a significant difference. In conclusion, walking with negative heel shoes induced significant changes in gait patterns, ground reaction forces, and energy consumption.     

Gait and metabolic adaptation of walking with negative heel shoes

The purpose of this study was to explore the gait pattern and metabolic responses of walking with negative heel shoes as compared to walking with normal shoes. Nineteen female subjects were recruited, of whom 13 (aged 23.08 ± 3.9 years, body weight 50.18 ± 5.3 kg, and body height 1.63 ± 0.05 m) participated in the gait pattern study, and 6 (age 32.8 ± 6.6 years, body weight 58.3 ± 5.8 kg, and body height 1.64 ± 0.01 m) in the metabolic study. In the gait pattern study, movement kinematics and kinetic data were obtained by video analysis and force platform measurement during the process of walking at a constant speed of 1.33 m/s on a treadmill and over ground, respectively. In the metabolic study, heart rate and oxygen consumption were monitored during treadmill walking. The results showed that there was a significant difference between walking on a treadmill with negative heel shoes and walking with normal shoes, in terms of stride cycle time, cadence, stride length, and angles of the ankle, knee, and hip joints. Differences also were found with the maximum and minimum ground reaction forces and their occurrence times. Metabolically, heart rate and oxygen consumption showed a significant difference. In conclusion, walking with negative heel shoes induced significant changes in gait patterns, ground reaction forces, and energy consumption.     

Changes in muscle activity in children with hemiplegic cerebral palsy while walking with and without ankle–foot orthoses

We compared the electromyographic (EMG) signals of lower extremity muscle groups in 10 children with hemiplegic cerebral palsy (CP) while walking barefoot and in a hinged ankle–foot orthosis (HAFO). All children had excessive plantarflexion and initial toe-contact on the affected side when walking barefoot, a typical gait pattern for hemiplegic patients. The patients walked with a physiological heel–toe gait pattern when wearing the HAFO. The peak activity of the tibialis anterior muscle was reduced by 36.1% at initial contact and loading response phase and by 57.3% just after toe-off when using a HAFO. The decrease in activity was thought to result from the change in gait pattern from a toe-gait to a heel–toe gait as well as the use of a HAFO. The HAFO also slightly decreased muscle activity in the proximal leg muscles mainly during swing phase, improved stride length, decreased cadence, improved walking speed, increased peak hip flexion, improved kinematics in loading response phase at the knee, and reduced the excessive ankle plantarflexion.     

Basic gait and symmetry measures for primary school-aged children and young adults whilst walking barefoot and with shoes

This study investigated the basic spatio-temporal gait measures of 898 primary school-aged children (5–13 years) and 82 young adults (18–27 years). Participants completed 6–8 walks at preferred speed along a GAITRite walkway whilst barefoot and whilst wearing athletic shoes or runners. Outcome measures (non-normalized and normalized) were gait speed, cadence, step and stride length, support base, single and double support, stance duration, foot angle and associated symmetry measures. Non-normalized measures of speed, step and stride length, support base and foot angle increased with age whereas cadence reduced. Normalized measures remained unchanged with age in children whereas the young adults (both conditions) exhibited a 2.3% reduction in single support, a 5.1% increase in double support and a 2.6% increase in stance duration (p < 0.0001). For the entire sample, shoes increased walking speed by 8 cm s⁻¹, step length by 5.5 cm, stride length by 11.1 cm and base of support by 0.5 cm. In contrast, foot angle and cadence reduced by 0.1° and 3.9 steps min⁻¹ respectively. Shoes increased both double support (1.6%) and stance time (0.8%), whereas single support reduced by 0.8%. Symmetry remained unaffected by age. On average, measures of step and stride symmetry (combining both conditions) fell around 0.7 cm, whereas measures of symmetry for step and stance time, single and double support fell around 0.6%. Footwear significantly affected gait (p < 0.0001). Gait may not be mature by age 13. Gait is symmetrical in healthy children and young adults but may change with pathology.     

Alterations in over-ground walking patterns in obese and overweight adults

Obesity has been associated with negative effects on postural control, including falls. Previous studies revealed different outcomes regarding the effects of obesity on gait features, and the use of BMI may lead to bias in assessing the true effects of obesity on gait. To better understand the effects of obesity on gait, it is important to examine gait features and associated body composition measures. The purpose of this study was: (1) to assess gait features of normal weight, overweight and obese adults, and (2) to assess the relationship between body composition measures and gait features. Thirty participants were assigned to one of three groups based upon their BMI at the onset of the study: healthy weight (BMI: 18.5–24.9 kg/m²), overweight (BMI: 25–29.9 kg/m²), or obese (BMI: 30–40 kg/m²). Participants performed straight-line over-ground walking through a 200 m hallway at their natural preferred speed while wearing their own shoes. The angular displacements, range of motion (ROM), and approximate entropy of kinematic data of the bilateral hips, knees, and ankles in the sagittal plane were computed. Walking speed, step length, stride length, single leg support phase, double leg support phase, swing phase and bilateral stance phase times were extracted from the GaitRite data. Overall, body mass and BMI were associated with peak flexion and ROM in the knees as well as single support, double support, stance, and swing phases. Body fat percentage did not exhibit correlations with measured gait features. Gait variables were more highly correlated with BMI and body mass instead of percent body fat, suggesting that absolute mass is more influential on gait features rather than amount of fat tissue.     

Influence of shoe midsole hardness on plantar pressure distribution in four basketball-related movements

This study examined how shoe midsole hardness influenced plantar pressure in basketball-related movements. Twenty male university basketball players wore customized shoes with hard and soft midsoles (60 and 50 Shore C) to perform four movements: running, maximal forward sprinting, maximal 45° cutting and lay-up. Plantar loading was recorded using an in-shoe pressure measuring system, with peak pressure (PP) and pressure time integral (PTI) extracted from 10 plantar regions. Compared with hard shoes, subjects exhibited lower PP in one or more plantar regions when wearing the soft shoes across all tested movements (Ps < 0.05). Lower PTI was also observed in the hallux for 45° cutting, and the toes and forefoot regions during the first step of lay-up in the soft shoe condition (Ps < 0.05). In conclusion, using a softer midsole in the forefoot region may be a plausible remedy to reduce the high plantar loading experienced by basketball players.     

The effect of footwear and footfall pattern on running stride interval long-range correlations and distributional variability

The presence of long-range correlations (self-similarity) in the stride-to-stride fluctuations in running stride interval has been used as an indicator of a healthy adaptable system. Changes to footfall patterns when running with minimalist shoes could cause a less adaptable running gait. The purpose of this study was to investigate stride interval variability and the degree of self-similarity of stride interval in runners wearing minimalist and conventional footwear. Twenty-six trained habitual rearfoot footfall runners, unaccustomed to running in minimalist footwear, performed 6-min sub-maximal treadmill running bouts at 11, 13 and 15 km·h⁻¹ in minimalist and conventional shoes. Force sensitive resistors were placed in the shoes to quantify stride interval (time between successive foot contacts). Footfall position, stride interval mean and coefficient of variation (CV), were used to assess performance as a function of shoe type. Long-range correlations of stride interval were assessed using detrended fluctuation analysis (α). Mean stride interval was 1-1.3% shorter (P = 0.02) and 27% of runners adopted a midfoot footfall (MFF) in the minimalist shoe. There was a significant shoe effect on α and shoe*speed*footfall interaction effect on CV (P < 0.05). Runners that adopted a MFF in minimalist shoes, displayed reduced long-range correlations (P < 0.05) and CV (P < 0.06) in their running stride interval at the 15 km·h⁻¹ speed. The reduced variability and self-similarity observed for runners that changed to a MFF in the minimalist shoe may be suggestive of a system that is less flexible and more prone to injury.     

Gait kinetics impact shoe tread wear rate

BackgroundAdequate footwear is an important factor for reducing the risk of slipping; as shoe outsoles wear down, friction decreases, and slip and fall risk increases. Wear theory suggests that gait kinetics may influence rate of tread wear.Research questionDo the kinetics of walking (i.e., the shoe-floor force interactions) affect wear rate?MethodsFourteen participants completed dry walking trials during which ground reaction forces were recorded across different types of shoes. The peak normal force, shear force, and required coefficient of friction (RCOF) were calculated. Participants then wore alternating pairs of shoes in the workplace each month for up to 24 months. A pedometer was used to track the distance each pair of shoes was worn and tread loss was measured. The wear rate was calculated as the volumetric tread loss divided by the distance walked in the shoes. Three, mixed linear regression models were used to assess the impact of peak normal force, shear force, and RCOF on wear rate.ResultsWear rate was positively associated with peak RCOF and with peak shear force, but was not significantly related to peak normal forces.SignificanceThe finding that shear forces and particularly the peak RCOF are related to wear suggests that a person’s gait characteristics can influence wear. Therefore, individual gait kinetics may be used to predict wear rate based on the fatigue failure shoe wear mechanism.     

The effects of altering attentional demands of gait control on the variability of temporal and kinematic parameters

The purpose of this study was to investigate the effects of cognitive and visuomotor tasks on gait control in terms of the magnitude and temporal structure of the variability in stride time and lower-limb kinematics measured using inertial sensors. Fourteen healthy young subjects walked on a treadmill for 15 min at a self-selected gait speed in the three conditions: normal walking without a concurrent task; walking while performing a cognitive task; and walking while performing a visuomotor task. The time series data of stride time and peak shank angular velocity were generated from acceleration and angular velocity data recorded from both shanks. The mean, coefficient of variation, and fractal scaling exponent α of the time series of these variables and the standard deviation of shank angular velocity over the entire stride cycle were calculated. The cognitive task had an effect on long-range correlations in stride time but not on lower-limb kinematics. The temporal structure of variability in stride time became more random in the cognitive task. The visuomotor task had an effect on lower-limb kinematics. Subjects controlled their swing limb with greater variability and had a more complex adaptive lower-limb movement pattern in the visuomotor task. The effects of the dual tasks on gait control were different for stride time and lower-limb kinematics. These findings suggest that the temporal structure of variability and lower-limb kinematics are useful parameters to detect a change in gait pattern and provide further insight into gait control.     

The effect of ankle bracing on knee kinetics and kinematics during volleyball‐specific tasks

The purpose of this study was to examine the effects of ankle bracing on knee kinetics and kinematics during volleyball tasks. Fifteen healthy, elite, female volleyball players performed a series of straight‐line and lateral volleyball tasks with no brace and when wearing an ankle brace. A 14‐camera Vicon motion analysis system and AMTI force plate were used to capture the kinetic and kinematic data. Knee range of motion, peak knee anterior–posterior and medial–lateral shear forces, and peak ground reaction forces that occurred between initial contact with the force plate and toe off were compared using paired sample t‐tests between the braced and non‐braced conditions (P < 0.05). The results revealed no significant effect of bracing on knee kinematics or ground reaction forces during any task or on knee kinetics during the straight‐line movement volleyball tasks. However, ankle bracing was demonstrated to reduce knee lateral shear forces during all of the lateral movement volleyball tasks. Wearing the Active Ankle T2 brace will not impact knee joint range of motion and may in fact reduce shear loading to the knee joint in volleyball players.     

Inexpensive footwear decreases joint loading in elderly women with knee osteoarthritis

Recent literature has highlighted that the flexibility of walking barefoot reduces overload in individuals with knee osteoarthritis (OA). As such, the aim of this study was to evaluate the effects of inexpensive, flexible, non-heeled footwear (Moleca^®) as compared with a modern heeled shoes and walking barefoot on the knee adduction moment (KAM) during gait in elderly women with and without knee OA. The gait of 45 elderly women between 60 and 70 years of age was evaluated. Twenty-one had knee OA graded 2 or 3 according to Kellgren and Lawrence's criteria, and 24 who had no OA comprised the control group (CG). The gait conditions were: barefoot, Moleca^®, and modern heeled shoes. Three-dimensional kinematics and ground reaction forces were measured to calculate KAM by inverse dynamics. For both groups, the Moleca^® provided peak KAM and KAM impulse similar to barefoot walking. For the OA group, the Moleca^® reduced KAM even more as compared to the barefoot condition during midstance. On the other hand, the modern heeled shoes increased this variable in both groups. Inexpensive, flexible, and non-heeled footwear provided loading on the knee joint similar to a barefoot gait and significant overload decreases in elderly women with and without knee OA, compared to modern heeled shoes. During midstance, the Moleca^® also allowed greater reduction in the knee joint loads as compared to barefoot gait in elderly women with knee OA, with the further advantage of providing external foot protection during gait.     

Gait biofeedback and impairment‐based rehabilitation for chronic ankle instability

Our purpose was to analyze the effects of 4 weeks of visual gait biofeedback (GBF) and impairment‐based rehabilitation on gait biomechanics and patient‐reported outcomes (PROs) in individuals with chronic ankle instability (CAI). Twenty‐seven individuals with CAI participated in this randomized controlled trial (14 received no biofeedback (NBF), 13 received GBF). Both groups received 8 sessions of impairment‐based rehabilitation. The GBF group received visual biofeedback to reduce ankle frontal plane angle at initial contact (IC) during treadmill walking. The NBF group walked for equal time during rehabilitation but without biofeedback. Dependent variables included three‐dimensional kinematics and kinetics at the ankle, knee, and hip, electromyography amplitudes of 4 lower extremity muscles (tibialis anterior, fibularis longus, medial gastrocnemius, and gluteus medius), and PROs (Foot and Ankle Ability Measure Activities of Daily Living (FAAM‐ADL), FAAM‐Sport, Tampa Scale of Kinesiophobia (TSK), and Global Rating of Change (GROC)). The GBF group significantly decreased ankle inversion at IC (MD:‐7.3º, g = 1.6) and throughout the entire stride cycle (peak inversion: MD:‐5.9º, g = 1.2). The NBF group did not have significantly altered gait biomechanics. The groups were significantly different after rehabilitation for the FAAM‐ADL (GBF: 97.1 ± 2.3%, NBF: 92.0 ± 5.7%), TSK (GBF: 29.7 ± 3.7, NBF: 34.9 ± 5.8), and GROC (GBF: 5.5 ± 1.0, NBF:3.9 ± 2.0) with the GBF group showing greater improvements than the NBF group. There were no significant differences between groups for kinetics or electromyography measures. The GBF group successfully decreased ankle inversion angle and had greater improvements in PROs after intervention compared to the NBF group. Impairment‐based rehabilitation combined with visual biofeedback during gait training is recommended for individuals with CAI.     

Comparison of knee gait kinematics of workers exposed to knee straining posture to those of non-knee straining workers

Workers exposed to knee straining postures, such as kneeling and squatting, may present modifications in knee gait kinematics that can make them vulnerable to osteoarthritis. In this study, knee kinematics of workers exposed to occupational knee straining postures (KS workers) were compared to those of non-knee straining (non-KS) workers. Eighteen KS workers and 20 non-KS workers participated in the study. Three-dimensional gait kinematic data were recorded at the knee using an electromagnetic motion tracking system. The following parameters were extracted from flexion/extension, adduction/abduction and internal/external rotation angle data and used for group comparisons: knee angle at initial foot contact, peak angles, minimal angles and angle range during the entire gait cycle. Group comparisons were performed with Student t-tests. In the sagittal plane, KS workers had a greater knee flexion angle at initial foot contact, a lower peak knee flexion angle during the swing phase and a lower angle range than non-KS workers (p < 0.05). In the frontal plane, all parameters indicated that KS workers had their knees more adducted than non-KS workers. External/internal rotation range was greater for KS workers. This study provides new knowledge on work related to KS postures and knee kinematics. The results support the concept that KS workers might exhibit knee kinematics that are different from those of non-KS workers.