Walking Stance Research Articles

The effect of screw insertion configuration of Sinus Tarsi plate on biomechanical performance using finite element analysis

Sinus Tarsi plates are used as implants for minimally invasive surgery of calcaneus bone fractures. This study evaluated the screw fixation patterns of Sinus Tarsi plates for optimal biomechanical performance. Six three-dimensional (3D) finite element models with different positional screws were evaluated for calcaneus fracture stabilization using Sinus Tarsi plates with 5, 6, and 7 holes. Walking stance conditions as heel strike, midstance, and push-off phases were used to compare loading. Results indicated that the equivalent (EQV) stress exhibited in the implant was higher than in the surrounding bone, with the highest value during the push-off phase. The maximum EQV stress or risk of failure decreased when an insertion screw was placed in the anterior bone using a 7-hole plate, and the most stable strain result at the fracture bone site was recorded for a Sinus Tarsi plate with 7 holes (TT 7-1). The screw insertion pattern and configuration of the Sinus Tarsi plate impacted the biomechanical performance of the calcaneal fracture.

EFFECTIVENESS OF STRENGTHENING EXERCISES IN IMPROVING FUNCTIONAL ACTIVITIES OF HEMIPLEGIC PATIENTS

Background of the Study: To determine the Effectiveness of Strengthening (Resistance) exercises in improving functional activities such as gross motor function and walking stance in stroke patients. Methodology: A Quasi experimental study was conducted. A Quasi experimental study was conducted; patients were selected from the OPD setting of Dr. Ziauddin Hospital, Saifee Hospital and the National medical center. Data was divided into two groups. Group 1 case and group 2 controls. The patients included in group 1, received Strengthening exercises. While, the other group received exercises other than strengthening such as Balance and Coordination Exercises, Flexibility Exercises, Functional Training and Gait Training, after which their improvement was recorded at the end of 4 weeks for 3 months. The critical outcomes evaluated subsequently to resistance training using therabands and minimal weights along with gait assessment, and functional training. Gait assessment, post-treatment using a 6-minute walk test (6MWT) and functional activities assessment scales using a Barthel Index. Results: The clinical intervention revealed significant results, showing that strength on the effected side increased post treatment as the calculated P-value was less than 0.05, also the mean leg strength for the RT group (pre walk_ 1.94 and 2.28 for control at baseline improved (post walk _to 2.71 for RT group and 1.60 for controls respectively after 3 months., suggested that resistance training produced marked improvement in performing functional activities of hemiplegic patients. Conclusions: Hence, it is concluded that the strengthening exercises including resistance band training and physio ball for upper limb and resistance training for lower limb were shown to improve Muscle strength and cause considerable improvement in performing the activities of everyday living and gait strength and core stability in patients suffering from stroke. Also, improving their social interactions and participation in everyday life.

Biomechanical role of bone grafting for calcaneal fracture fixation in the presence of bone defect: A finite element analysis

BackgroundThe purpose of this study was to compare the biomechanical stress and stability of calcaneal fixations with and without bone defect, before and after bone grafting, through a computational approach. MethodsA finite element model of foot-ankle complex was reconstructed, impoverished with a Sanders III calcaneal fracture without bone defect and with moderate and severe bone defects. Plate fixations with and without bone grafting were introduced with walking stance simulated. The stress and fragment displacement of the calcaneus were evaluated. FindingsModerate and severe defect increased the calcaneus stress by 16.11% and 32.51%, respectively and subsequently decreased by 10.76% and 20.78% after bone grafting. The total displacement was increased by 3.99% and 24.26%, respectively by moderate and severe defect, while that of posterior joint facet displacement was 86.66% and 104.44%. The former was decreased by 25.73% and 35.96% after grafting, while that of the latter was reduced by 88.09% and 84.78% for moderate and severe defect, respectively. InterpretationOur finite element prediction supported that bone grafting for fixation could enhance the stability and reduce the risk of secondary stress fracture in cases of bone defect in calcaneal fracture.

Isolating the speed factor is crucial in gait analysis for Parkinson's disease.

Parkinson's disease (PD) is characterized by an alteration of the walking gait, frequently including a slower self-selected walking speed (SSWS). Although the reduction of walking speed is inherent to people with PD, such speed reduction also represents a potential confounding factor that might partly explain the observed gait differences between PD and control participants. In this study, each participant walked along a 25 m level corridor during which vertical ground reaction force signals were recorded using shoes equipped with eight pressure sensors. Vertical ground reaction force signals (using statistical parametric mapping) and temporal and kinetic variables as well as their related variability and asymmetry (using Student's t-test) were compared between PD (n = 54) and walking-speed-matched control subjects (n = 39). Statistical parametric mapping did not yield significant differences between PD and control groups for the vertical ground reaction force signal along the walking stance phase. Stride time and single support time (equivalent to swing time) were shorter and peak vertical ground reaction force was larger in PD patients compared to controls (p ≤ 0.05). However, the single support time was no longer different between people with PD and healthy subjects when expressed relatively to stride time (p = 0.07). While single support, double support, and stance times were significantly more variable and asymmetric for PD than for the control group (p ≤ 0.05), stride time was similar (p ≥ 0.07). These results indicate that at matched SSWS, PD patients adopt a higher cadence than control participants. Moreover, the temporal subdivision of the walking gait of people with PD is similar to healthy individuals but the coordination during the double support phase is different. Hence, this study indicates that isolating the speed factor is crucial in gait analysis for PD.

Sway and Acceleration Changes of the Center of Mass during Walking Stance Phase before and after Total Knee Arthroplasty

Elucidating the sway and changes in the acceleration of center of mass (COM) during walking is important for effective gait training and rehabilitation. The objective of this study was to verify the improvement in gait before and after total knee arthroplasty (TKA) from COM sway and the changes in the acceleration of COM during the stance phase of walking. This study included 13 patients (1 male and 12 females) with medial knee osteoarthritis who were hospitalized for TKA. The COM sway during the stance phase of walking was evaluated using root mean square (RMS) normalized by walking speed, and the changes in acceleration were further verified. Lateral and vertical RMS showed significant differences between preoperative and postoperative states and demonstrated low values after TKA. The lateral acceleration at the latter part of the early stance phase demonstrated a significant difference between preoperative and postoperative states. A significant difference was also observed in the lateral acceleration in the late stance phase between the two groups. Improvement in pain and alignment after TKA reduced the lateral sway of COM and the changes in acceleration during the gait stance phase, which is speculated to lead to improvement in gait and prevention of falls.

The Influence of Different Footwear Insole Stiffness on Center of Pressure and Ankle Kinematics during Walking: A Case Report

During locomotion, the foot–ankle system plays an important role for forward progression of the body. The center of pressure (COP) is regarded as the point of the ground reaction force (GRF) vector acting on the foot surface during the stance phase. COP movement trajectory and velocity reflect the stance phase forward progression of the foot segment and the ankle joint motion characteristics. This study aimed to investigate different levels of footwear insole stiffness on COP forward velocity, GRF and ankle joint angles during walking stance phase. Two healthy subjects (one female, one male; age 26.5 ± 6.4 years, height 168.5 ± 2.1 cm, weight 64.9 ± 5.4 kg) participated in this study. Subjects were asked to walk along a 10 m walkway at two different speeds: self–selected normal (SSN) and self–selected fast (SSF). Within each walking speed, subjects were required to walk under two different insole stiffness conditions: (1) normal shoe insole (NSI) from the testing shoe (Nike Free RN Flyknit 2017) used in this study; (2) 1.6 mm thick carbon fiber insole (CFI) fitted within the testing shoe. Stiffer insole (CFI) significantly decreased peak ankle internal rotation angle (p = 0.001) and sagittal plane angle ROM (p = 0.022); additionally, CFI significantly increased peak ankle eversion angle compared to the NSI condition (p = 0.028). In conclusion, increasing footwear insole stiffness would alter stance phase ankle joint motion at SSF walking speed. Additionally, stiffer insoles may tend to decrease COP peak velocity at the initial heel strike and the terminal stance phase. Future research should investigate the combined effects of various insole properties on lower extremity system kinematic and kinetic patterns in various locomotion activities.

Plantarflexion Moment Prediction during the Walking Stance Phase with an sEMG-Ultrasound Imaging-Driven Model.

Many rehabilitative exoskeletons use non-invasive surface electromyography (sEMG) to measure human volitional intent. However, signals from adjacent muscle groups interfere with sEMG measurements. Further, the inability to measure sEMG signals from deeply located muscles may not accurately measure the volitional intent. In this work, we combined sEMG and ultrasound (US) imaging-derived signals to improve the prediction accuracy of voluntary ankle effort. We used a multivariate linear model (MLM) that combines sEMG and US signals for ankle joint net plantarflexion (PF) moment prediction during the walking stance phase. We hypothesized that the proposed sEMG-US imaging-driven MLM would result in more accurate net PF moment prediction than sEMG-driven and US imaging-driven MLMs. Synchronous measurements including reflective makers coordinates, ground reaction forces, sEMG signals of lateral/medial gastrocnemius (LGS/MGS), and soleus (SOL) muscles, and US imaging of LGS and SOL muscles were collected from five able-bodied participants walking on a treadmill at multiple speeds. The ankle joint net PF moment benchmark was calculated based on inverse dynamics, while the net PF moment prediction was determined by the sEMG-US imaging-driven, sEMG-driven, and US imaging-driven MLMs. The findings show that the sEMG-US imaging-driven MLM can significantly improve the prediction of net PF moment during the walking stance phase at multiple speeds. Potentially, the proposed sEMG-US imaging-driven MLM can be used as a superior joint motion intent model in advanced and intelligent control strategies for rehabilitative exoskeletons.

A Pilot Study of Muscle Force between Normal Shoes and Bionic Shoes during Men Walking and Running Stance Phase Using Opensim

The original idea for bionic shoes (BSs) involves combining the function of unstable foot conditions and the structure of the human plantar. The purpose of this study was to investigate the differences between the normal shoes (NS) and the BS during the stance phases of walking and running. A total of 15 Chinese males from Ningbo University were recruited for this study (age: 24.3 ± 2.01 years; height: 176.25 ± 7.11 cm, body weight (BW): 75.75 ± 8.35 kg). The participants were asked to perform a walking and running task. Statistical parametric mapping (SPM) analysis was used to investigate any differences between NSs and BSs during the walking and running stance phases. The results demonstrated that there were significant differences found (21.23–28.24%, p = 0.040; 84.47–100%, p = 0.017) in hip extension and flexion between the NS and the BS during the walking stance phase. There were no significant differences found in ankle and moment during the running stance phase. Significant differences were found in the rectus femoris (5.29–6.21%; p = 0.047), tibialis anterior (14.37–16.40%; p = 0.038), and medial gastrocnemius (25.55–46.86%; p < 0.001) between the NS and the BS during the walking stance phase. Significant differences were found in rectus femoris (12.83–13.10%, p = 0.049; 15.89–80.19%, p < 0.001), tibialis anterior (15.85–18.31%, p = 0.039; 21.14–24.71%, p = 0.030), medial gastrocnemius (80.70–90.44%; p = 0.007), and lateral gastrocnemius (11.16–27.93%, p < 0.001; 62.20–65.63%, p = 0.032; 77.56–93.45%, p < 0.001) between the NS and the BS during the running stance phase. These findings indicate that BSs are more efficient for muscle control than unstable shoes and maybe suitable for rehabilitation training.

Biomechanical comparison among five mid/hindfoot arthrodeses procedures in treating flatfoot using a musculoskeletal multibody driven finite element model

Background and objectiveMid/hindfoot arthrodesis could modify the misalignment of adult-acquired flatfoot and attenuate pain. However, the long-term biomechanical effects of these surgical procedures remain unclear, and the quantitative evidence is scarce. Therefore, we aimed to investigate and quantify the influences of five mid/hindfoot arthrodeses on the internal foot biomechanics during walking stance. MethodsA young participant with flexible flatfoot was recruited for this study. We reconstructed a subject-specific musculoskeletal multibody driven-finite element (FE) foot model based on the foot magnetic resonance imaging. The severe flatfoot model was developed from the flexible flatfoot through the attenuation of ligaments and the unloading of the posterior tibial muscle. The five mid/hindfoot arthrodeses simulations (subtalar, talonavicular, calcaneocuboid, double, and triple arthrodeses) and a control condition (no arthrodesis) were performed simultaneously in the detailed foot multibody dynamics model and FE model. Muscle forces calculated by a detailed multi-segment foot model and ground reaction force were used to drive the foot FE model. The internal foot loadings were compared among control and these arthrodeses conditions at the first and second vertical ground reaction force (VGRF) peak and VGRF valley instants. ResultsThe results indicated that the navicular heights in double and triple arthrodeses were higher than other surgical procedures, while the subtalar arthrodesis had the smallest values. Five mid/hindfoot arthrodeses reduced the peak plantar fascia stress compared to control. However, double and triple arthrodeses increased the peak medial cuneo-navicular joint contact pressures and peak foot pressures as well as the metatarsal bones stresses. ConclusionAlthough mid/hindfoot arthrodesis generally reduced the collapse of medial longitudinal arch and plantar fascia loading during the stance phase, the increased loading in the adjacent unfused joint and metatarsal bones for double and triple arthrodeses should be noted. These findings could account for some symptoms experienced by flatfoot patients after surgery, which may facilitate the optimization of surgical protocols.

Influence of arch support heights on the internal foot mechanics of flatfoot during walking: A muscle-driven finite element analysis

BackgroundDifferent arch support heights of the customized foot orthosis could produce different effects on the internal biomechanics of the foot. However, quantitative evidence is scarce. Therefore, we aimed to investigate and quantify the influence of arch support heights on the internal foot biomechanics during walking stance. MethodsWe reconstructed a foot finite element model from a volunteer with flexible flatfoot. The model enabled a three-dimensional representation of the plantar fascia and its interactions with surrounding osteotendinous structures. The volunteer walked in foot orthosis with different arch heights (low, neutral, and high). Muscle forces during gaits were calculated by a multibody model and used to drive a foot finite element model. The foot contact pressures and plantar fascia strains in different regions were compared among the insole conditions at the first and second vertical ground reaction force (VGRF) peak and VGRF valley instants. ResultsThe results indicated that peak foot pressures decreased in balanced standing and second VGRF as the arch support height increased. However, peak midfoot pressures increased during all simulated instants. Meanwhile, high arch support decreased the plantar fascia loading by 5%–15.4% in proximal regions but increased in the middle and distal regions. ConclusionAlthough arch support could generally decrease the plantar foot pressure and plantar fascia loading, the excessive arch height may induce high midfoot pressure and loadings at the central portion of the plantar fascia. The consideration of fascia-soft tissue interaction in modeling could improve the prediction of plantar fascia strains towards design optimization for orthoses.

THE EFFECTS OF INCREASING INSOLE STIFFNESS ON FOOT AND ANKLE MECHANICS IN WALKING GAIT

The energetic pattern of the foot–ankle system is critical in human walking gait. While some of the mechanical energy was dissipated due to foot segment deformation in walking stance phase. Increasing footwear insole bending stiffness was reported to restrict foot segment bending behavior and this was reported to reduce foot segment energy dissipation. While little is known whether increasing footwear insole bending stiffness would alter foot–ankle system mechanical work generation and absorption patterns. Two healthy subjects (one female, one male; age [Formula: see text] years, height [Formula: see text][Formula: see text]cm, weight [Formula: see text][Formula: see text]kg) participated in this study and they were asked to walk at self-selected normal speed with the same footwear (Nike Free RN Flyknit, 2017) in two different insole stiffness conditions: (i) normal shoe insole (NSI); (ii) carbon fiber insole (CFI). Paired sample [Formula: see text]-test was conducted between NSI and CFI for all outcome measures. No statistically significant differences in the outcome variables were found between the two insole conditions. While foot segment positive work and mechanical work ratio were 45.54% and 68.43% higher in CFI than in NSI condition, respectively; foot negative work was 25.02% lower in CFI than in NSI condition. However, ankle joint positive work and work ratio were around more than 10% higher in NSI than in CFI condition, and ankle peak positive power in NSI was 23.93% higher than in CFI condition. Additionally, foot–ankle system overall positive work and mechanical work ratio were both similar between NSI and CFI conditions. The findings indicate increasing footwear insole bending stiffness may influence foot segment and ankle joint energetic patterns in walking stance phase. And the mechanical energy generation compensatory mechanism may exist between foot segment and ankle joint. Specifically, a decreased foot segment energy generation tended to result in a higher amount of ankle joint positive work and peak power generation. This will be beneficial for maintaining a relatively consistent foot–ankle system overall energy generation and work ratio in response to altered insole stiffness and foot segment work during gait.

The effect of eight-week elastic walking exercise on the pattern of plantar pressure distribution in women with chronic low back pain during walking

Background: Training of elastic walking is a new method for elasticity in gait and correction of the distribution pattern of plantar pressure in patients with low back pain during gait. This study aimed to investigate the distribution pattern of plantar pressure during gait in women with low back pain following 8 weeks-training of elastic walking. Methods: The present study was quasi-experimental. In this research, 20 women with low back pain were divided into control (n=11) and experimental (n=9) groups. Subjects from the experimental group performed elastic gait training for 3 sessions per week for 8 weeks while the control group didn’t have any exercise program. The plantar pressure variables included the peak of vertical ground reaction forces, the time to peak of ground reaction forces, loading rate, the peak of plantar pressure on the ten foot regions, the peak of ground reaction forces on the ten foot regions, and displacement of the pressure center in two internal-external (copx) and anterior-posterior (copy) lines. The distribution pattern of plantar pressure during gait was recorded by a foot scan system (Sampling rate 300 Hz) in pre-training and post-training. Two-way ANOVA was used to analyze the data. The significance level was set at P < 0.05. Results: In the experimental group, the results of this study demonstrated lower peak vertical reaction force (FzMS component) during post-test compared with pre-test (P = 0.002). Moreover, findings showed that the main effect of group on peak pressure in the mid-foot region was significant (P = 0.011). The results showed no significant difference concerning the main effect of group, the main effect of time and effect, interaction time and group on peak vertical reaction force, displacement of pressure center, vertical loading rate, and walking stance time (P > 0.05). Conclusion: The findings of this study showed that training of elastic walking does not have a significant effect on stance time. Also, training of elastic walking in the experimental group reduced the peak vertical ground reaction force (FzMS component) during the post-test compared with the pre-test that can correct the walking pattern and improve the chronic low back pain.

Finite element method based parametric study of Gastrocnemius-soleus recession: implications to the treatment of midfoot-forefoot overload syndrome

Gastrocnemius-soleus recession has been used to treat midfoot-forefoot overload syndrome and plantar fasciitis induced by equinus of the ankle joint. A controlled and selective amount of recession is imperative to maintain muscle strength and stability. The objective of this study was to conduct a parametric study to quantify the relationship between the level of recession and plantar fascia stress. A finite element model of the foot-ankle-shank complex was reconstructed from magnetic resonance and computed tomography images of a 63-year-old normal female. The model was validated by comparing modeled stresses to the measured plantar pressure distribution of the model participant during balanced standing. The midstance and push-off instants of walking stance were simulated with different levels and combinations of gastrocnemius-soleus recession resembled by different amounts of muscle forces. Halving the muscle forces at midstance reduced the average plantar fascia stress by a quarter while reducing two-third of the muscle forces at push-off reduced the average fascia stress by 18.2%. While the first ray of the plantar fascia experienced the largest stress among the five fasciae, the stress was reduced by 77.8% and 16.9% when the load was halved and reduced by two-third at midstance and push-off instants, respectively. Reduction in fascia stress implicates a lower risk of plantar fasciitis and other midfoot-forefoot overload syndromes. The outcome of this study can aid physicians to determine the amount of gastrocnemius-soleus recession towards patients with vdifferent levels of plantar fascia overstress. A detailed three-dimensional modelling on the plantar fascia is warranted in future study.

Comparison of Foot Pressure Variables in Blind and Healthy Participants with Open and Closed Eyes While Walking

Introduction: Measurement of foot pressure variables can be used to assess the loads to which the human body is subjected in normal activities, like walking, or in more demanding situations such as sports. The purpose of this study was to compare the foot pressure variables in blind and healthy individuals with open and closed eyes during walking. Methods: The present study was a quasi-experimental and laboratory study with pretest-posttest design. The statistic samples included 13 blind men with the mean age of 29.05±3.28 years and 17 healthy men with the mean age of 24.22±1.31 years participated in this study and were selected by available sampling method.. A foot scan (RS Scan International, Belgium) set was used for measuring planter pressure during walking. Variables data were recorded at a sampling frequency of 300 Hz. For data analysis, paired t-test was run to compare the means within the group; also, independent t-test run to compare the means between the groups using SPSS ver. 16 statistical software. Results: The results showed that the peak reaction time of the ground reaction force during the heel contact phase was 45.89% higher than blind people compared to the normal participants (p<0.023). The time to peak of vertical force during mid stance in the blind people was 38.97% more than in normal people with closed eyes (p<0.013). The peak vertical loading rate in the blind people was 41.65% lower than normal participants with closed eyes while walking (p<0/003). Conclusion: Congenital blind people have less stance time in comparison with the healthy people with closed eyes. Decreased walking stance time seems to be related to improved their other senses that requires further research.

In vitro study of foot bone kinematics via a custom-made cadaveric gait simulator

BackgroundQuantifying detailed kinematics of the intrinsic foot bone during gait is crucial for understanding biomechanical functions of the foot complex musculoskeletal structure and making appropriate surgery decisions.Research questionThe purpose of this experiment is to measure bone kinematic of the normal foot in a gait cycle via a custom-made cadaveric gait simulator.MethodsIn this experiment, we used a custom-made 6 degrees of freedom (DOF) of robotic gait simulator simulating normal human gait to measure the 3-dimensional (3D) kinematics of tibia, calcaneus, cuboid, navicular, medial cuneiform, first metatarsal, and fifth metatarsal through six cadaveric feet.ResultsThe results showed that the kinematic of the intrinsic foot bones in the stance phase of the gait was successfully quantified using a custom-made robotic gait simulator. During walking stance, the joints in the medial column of foot had less movement than those in the lateral column. And during the later portion of stance, no rotational cease was observed in the movement between navicular and cuboid, calcaneocuboid joint, or cuneonavicular joint.ConclusionThis study described foot bone motion using a biomechanically near-physiological gait simulator with 6 DOF of the tibia. The kinematic data helps to clarify previous descriptions of several joint kinematics that are difficult to study in vivo. The methodology also provides a platform for researchers to explore more invasive foot biomechanics under dynamic and near-physiologic conditions.

Electronic system for step width estimation using programmable system-on-chip technology and time of flight cameras

This paper proposes a low-cost portable electronic system for estimating step width during the human gait cycle. This device, intended to support the Walking Stance item of the fall risk assessment test Performance Oriented Mobility Assessment (POMA), contains three electronic boards, comprising two sensing nodes and a concentrator. Each sensing node contains a force sensitive resistor (FSR) and time-of-flight camera (TOF). Each FSR is placed inside the subject’s shoe, while each TOF camera is located at the back of their foot. The FSR detects contact between heel and ground, and the TOF measures the distance to a barrier located on the right side of the walking path. Step width is calculated as the difference between the TOF measurements. After the walk is complete, the information obtained by the FSRs and TOFs is sent via a 433 MHz wireless communication to the concentrator board, which is connected to the USB port of a personal computer (PC). The proposed step width measurement system was validated with an infrared based motion capture (Vicon Corp.), giving an error equal to 11.4% ± 5.5%.

Relationship Between the Walking Velocity Relative to the Slip Velocity and the Corrective Response

During walking, the slip velocity relative to the center of mass velocity can be one of the determinants of falls. We hypothesized that participants would select their strategy (classified by strategy type and measured by the distance of recovery landing or next forward stepping) according to both walking velocity and stance of legs. This study aimed to assess the relationship between the walking velocity relative to the slip velocity (maximum 1.6 m/s) and the corrective response and evaluated the element of the posture at the moment of slipping associated with the corrective response. Ten healthy young adults showed leading leg perturbation in two isolated velocity conditions during over ground walking (slow: 0.9 m/s, fast: 1.6 m/s) using a built-in, double-belt treadmill. We defined the corrective response to perturbation as the change in the heel marker distance post-perturbation. We examined the postural parameters affecting the difference in corrective response. During fast walking, at a velocity near the maximum slip velocity, all participants overcame slipping and kept walking. During slow walking, at a velocity less than the maximum slip velocity, most of the participants took wide steps or stepped backwards and stopped walking. During slow walking, the step length (r = 0.84, p < 0.01) and the hip flexion angle (r = 0.78, p < 0.01) were strongly correlated with corrective response. One of the targets of the therapeutic interventions may be expanding the hip’s range of motion to secure a stable base of support for elderly people with slow walking velocity.

Effects of Long-Term Use of Insoles with a Toe-Grip Bar on the Balance, Walking, and Running of Preschool Children: A Randomized Controlled Trial.

This randomized controlled study is aimed at investigating the effects of long-term use of insoles with a toe-grip bar on the balance, walking, and running of preschool children. Fifty-two preschool children were randomly assigned to an intervention group or control group. Children included in the intervention group wore shoes with insoles that had a toe-grip bar, and those in the control group wore shoes with regular insoles without a toe-grip bar for 4 weeks while they were at school. The center of gravity sway (total trajectory length and envelope area), walking parameters (walking speed, cadence, stride length, step length, stance time, and swing time), and time to run 25 m were measured before and after the intervention. The 25 m running time of the intervention group was significantly improved after the intervention (F = 5.66; p < 0.05). This study suggests that insoles with a toe-grip bar may contribute to improvements in the running of preschool children.

In vivo talocrural and subtalar kinematics during the stance phase of walking in individuals with repetitive ankle sprains

Ankle sprains may lead to chronic ankle instability and can progress to ankle osteoarthritis due to the abnormal kinematics after an ankle sprain. However, the characteristics of talocrural and subtalar joint kinematics in individuals with repetitive ankle sprains during locomotion is unclear. The purpose of this study was to quantify the differences of talocrural and subtalar joint kinematics between individuals with and without history of ankle sprains during the walking stance phase. Lateral fluoroscopic images from 10 participants with history of repetitive ankle sprains (AS group) and 8 healthy volunteers (Control group) were obtained between the time of heel contact and toe-off, and the three-dimensional bone orientations were determined using 3D-2D model-image registration techniques to compare the kinematic differences between the two groups. The AS group exhibited a greater talocrural internal rotation from heel contact to 60% of the stance phase than the control group. The results of this study indicate that ankles with repetitive sprains have different talocrural kinematics, and that greater talocrural internal rotation may become a factor in the development of ankle osteoarthritis.

Influence of Pain on Knee Joint Movement and Moment during the Stance Phase in Patients with Severe Bilateral Knee Osteoarthritis: A Pilot Study

Background and Objectives: The purpose of this study was to compare the side-to-side differences in knee joint movement and moment for the degree of pain in the walking stance phase in patients with bilateral knee osteoarthritis (KOA) of comparable severity. We hypothesized that knee joint movement and moment on the side with strong pain were lower compared with the side with weak pain. Materials and Methods: We included 11 patients diagnosed with bilateral severe KOA. In all patients’ left and right knees, the Kellgren–Lawrence radiographic scoring system grade was level 4, and the femorotibial angle and knee range of motion were equivalent. Following patients’ interviews with an orthopedic surgeon, we performed a comparative study with KOA with strong pain (KOAs) as the strong painful side and KOA with weak pain (KOAw) as the weak painful side. Data for changes in bilateral knee joint angles in three dimensions during the stance phase and bilateral knee sagittal and frontal moments exerted in the early and late stance phases were extracted from kinematics and kinetics analyses. Results: Three-dimensional joint movements in the knee joint were not significantly different in all phases between KOAs and KOAw. Knee extensor moment in the early stance phase in KOAs was significantly smaller than that in KOAw. Knee abductor moment in the early and late stance phase was not significantly different between KOAs and KOAw. Conclusions: Although we found no difference in joint motion in bilateral knee joints, knee extensor moment on the side with strong pain was decreased. In patients with bilateral severe KOA, it was suggested that the magnitude of knee pain contributed to the decrease in knee joint function.