Gait ground reaction force characteristics of low back pain patients with pronated foot and able-bodied individuals with and without foot pronation

Comparison of foot kinematics and ground reaction force characteristics during walking in individuals with highly and mildly pronated feet

BACKGROUND

Individuals with highly pronated feet (PF) are more prone to lower extremity injuries than those with mildly PF. However, whether foot kinematics and ground reaction force (GRF) characteristics differ according to the severity of PF deformity is unclear.

RESEARCH QUESTION

Are there differences in foot kinematics and GRF characteristics during walking between individuals with mildly PF and those with highly PF?

METHODS

Ten individuals with mildly PF and 10 with highly PF (six-item foot posture index scores: 6-9 and 10-12 points, respectively) participated in this study. A three-dimensional motion analysis system measured participants' foot kinematics and GRF characteristics during gait trials.

RESULTS

Participants with highly PF exhibited significantly lower medial longitudinal arch heights than those with mildly PF from 0 % to 90 % of the stance phase (p < 0.05). No significant differences were observed in any of the angles between the foot segments. Additionally, participants with highly PF exhibited significantly larger posterior GRF than those with mildly PF from 2 % to 7 % of the stance phase (p < 0.05). Participants with highly PF also exhibited significantly larger anterior GRF than those with mildly PF, from 62 % to 82 % of the stance phase (p < 0.05).

SIGNIFICANCE

The results of this study suggest that the more severe the PF deformity, the more inefficient the foot ground force transmission, and the stronger the load applied to the foot. These results may be related to the higher incidence of lower extremity injuries in individuals with highly PF than in those with mildly PF.

Muscle activation while running on the ground compared to artificial turf in males with pronated and supinated feet

BACKGROUND

Running on different surfaces, including natural and artificial surfaces, requires different gait mechanics, especially in individuals with foot deformity.

RESEARCH QUESTION

How muscle activity change during running on the ground and artificial turf in males with pronated and supinated feet?

METHODS

In this quasi-experimental study, we assessed a cohort of young male subjects, classified as healthy (n = 10), and with pronated (n = 10) or supinated (n = 10) feet. An electromyographic system was used to record lower limb muscle activity while running on the ground and artificial turf at constant speed (3.2 m/s).

RESULTS

Results demonstrated significant main effects of the "surface" factor for vastus medialis activity during the loading phase (p = 0.040, η2 =0.147). Paired comparison revealed significantly greater vastus medialis activity while running on artificial grass with respect to the ground. A significant effect of the "group" factor was found for medial gastrocnemius during loading phase (p = 0.020, η2 =0.250). Paired-wise comparison revealed significantly lower medial gastrocnemius activity in the pronated and supinated feet groups than in the healthy group.

SIGNIFICANCE

The healthy group may possess better neuromuscular control, allowing them to effectively coordinate the activation of the medial gastrocnemius with other muscles involved in running. Based on these findings, running on artificial turf is useful when the runner would like to strengthen vastus medialis muscle. The runner should carefully choose the running surface according to his/her state and training session goal.

The Impact of Excessive Body Weight and Foot Pronation on Running Kinetics: A Cross-Sectional Study

BACKGROUND

Running exercise is an effective means to enhance cardiorespiratory fitness and body composition. Besides these health benefits, running is also associated with musculoskeletal injuries that can be more prevalent in individuals with excessive body weight. Little is known regarding the specific effects of overweight and foot pronation on ground reaction force distribution during running. Therefore, this study aimed to investigate the effects of overweight/obesity and foot pronation on running kinetics.

METHODS

Eighty-four young adults were allocated to four experimental groups: non-excessive body weight/non-pronated feet; non-excessive body weight/pronated feet; overweight or obesity/ non-pronated feet and overweight or obesity/pronated feet. Biomechanical testing included participants to run at ~ 3.2 m/s over an 18-m walkway with an embedded force plate at its midpoint. Three-dimensional ground reaction forces were recorded and normalized to body mass to evaluate running kinetics from 20 running trials. Test-re-test reliability for running speed data demonstrated ICC > 0.94 for each group and in total.

RESULTS

The results indicated significantly lower vertical impact peak forces (p = 0.001, effect size = 0.12), shorter time to reach the vertical impact peak (p = 0.006, effect size = 0.08) and reduced vertical loading rate (p = 0.0007, effect size = 0.13) in individuals with excessive body weight (overweight or obesity/non-pronated feet group and overweight or obesity/pronated feet) compared with individuals non-excessive body weight (non-excessive body weight/non-pronated feet and non-excessive body weight/pronated feet). Moreover, the excessive body weight groups presented lower peak braking (p = 0.01, effect size = 0.06) and propulsion forces (p = 0.003, effect size = 0.09), lower medio-lateral loading rate (p = 0.0009, effect size = 0.12), and greater free moments (p = 0.01, effect size = 0.07) when compared to the non-overweight groups. Moreover, a significant body mass by foot pronation interaction was found for peak medio-lateral loading rate. Non-excessive body weight/pronated feet, excessive body weight/non-pronated feet and excessive body weight/pronation groups presented lower medio-lateral loading rates compared to non-excessive body weight/non-pronated feet (p = 0.0001, effect size = 0.13).

CONCLUSIONS

Our results suggest that excessive body weight has an impact on ground reaction forces during running. We particularly noted an increase in medio-lateral and torsional forces during the stance phase. Individuals with excessive body weight appear to adapt their running patterns in an effort to attenuate early vertical impact loading.

The effect of severe obesity on three-dimensional ground reaction force signals during walking

BACKGROUND

The gait pattern of adults with class I obesity [30 ≤ body mass index < 35kg/m²] was characterized by altered three-dimensional ground reaction force signals compared to lean adults (18.5 ≤ body mass index < 25 kg/m²). However, results might not be generalizable to adults with severe obesity (class II and III; body mass index ≥ 35 kg/m²). Hence, the purpose of the present study was to investigate the differences in relative ground reaction force signals, i.e., normalized by body weight, between adults with severe obesity and lean adults using functional principal component analysis.

METHODS

Thirteen lean and eighteen sedentary adults with severe obesity performed a 5-min walking trial (1.11 m/s) on an instrumented treadmill. The first five functional principal components of the relative force signals (mediolateral, anterior-posterior, and vertical directions) were obtained using functional principal component analysis. Functional principal component scores were compared between groups using an analysis of covariance with age as covariable.

FINDINGS

Functional principal component analysis reported a statistically significant group effect for first functional principal component score for mediolateral (P = 0.004), and second and fifth functional principal component scores for anterior-posterior (P ≤ 0.02) force signals. Adults with severe obesity displayed a greater mediolateral force during most of the stance but similar magnitudes of the anterior-posterior and vertical forces compared to lean adults.

INTERPRETATION

Therefore, increasing the obesity level accentuates differences in mediolateral force but promotes no specific changes in anterior-posterior force likely due to chronic loading adaptation.

Effects of an 8-week multimodal exercise program on ground reaction forces and plantar pressure during walking in boys with autism spectrum disorder

BACKGROUND

Autism spectrum disorder is a developmental disability with first signs appearing in children aged 3 years and younger. Given that autism spectrum disorder is accompanied by a broad range of symptoms such as impaired sensory, neurological, and neuromotor functions, it appears plausible to argue that an intervention program focusing on multimodal exercise rather than single-mode exercise might be more effective in treating this wide variety of symptoms.

OBJECTIVE

The aim of this study was to evaluate the effects of a multimodal exercise program entitled Sports, Play, and Active Recreation for Kids on variables of ground reaction forces and plantar pressure during walking in boys with autism spectrum disorder.

METHODS

Twenty-four autism spectrum disorder boys aged 7-11 years were recruited and randomly allocated into an intervention or a waiting control group. Sports, Play, and Active Recreation for Kids was conducted over a period of 8 weeks with three weekly sessions. This training protocol includes aerobic dance and jump rope exercises as well as running games. Pre- and post-training, ground reaction forces and plantar pressure variables were recorded while walking at a constant walking speed of 0.9 m/s using a foot scan embedded in a 15-m walkway.

RESULTS

Significant group-by-time interactions were found for the first peak of vertical ground reaction force, loading rate, and peak pressure at the medial heel region (all p = 0.001-0.49, d = 0.89-1.40). Post-hoc analyses showed significant pre-post decreases for the first peak of vertical ground reaction force (p = 0.001, d = 1.27), loading rate (p = 0.009, d = 1.11), and peak pressure at the medial heel region (p = 0.021, d = 1.01).

CONCLUSIONS

Our results suggest that a joyful and multimodal exercise program has positive effects on kinetic walking characteristics of autism spectrum disorder boys. Accordingly, we recommend to implement this type of exercise in prepubertal autism spectrum disorder boys to improve gait kinetics.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials IRCT20170806035517N4. Registered on November 8, 2021. This study was approved by the Ethical Committee of the University of Mohaghegh Ardabili, Ardabil, Iran (IR.UMA.REC.1400.019). The study was conducted in accordance with the latest version of the Declaration of Helsinki.

A novel implantable mechanism-based tendon transfer surgery for adult acquired flatfoot deformity: Evaluating feasibility in biomechanical simulation

Adult acquired flatfoot deformity becomes permanent with stage III posterior tibialis tendon dysfunction and results in foot pain and difficulty walking and balancing. To prevent progression to stage III posterior tibialis tendon dysfunction when conservative treatment fails, a flexor digitorum longus to posterior tibialis tendon transfer is often conducted. However, since the flexor digitorum longus only has one-third the force-capability of the posterior tibialis, an osteotomy is typically also required. We propose the use of a novel implantable mechanism to replace the direct attachment of the tendon transfer with a sliding pulley to amplify the force transferred from the donor flexor digitorum longus to the foot arch. In this work, we created four OpenSim models of an arched foot, a flatfoot, a flatfoot with traditional tendon transfer, and a flatfoot with implant-modified tendon transfer. Paired with these models, we developed a forward dynamic simulation of the stance phase of gait that reproduces the medial/lateral distribution of vertical ground reaction forces. The simulation couples the use of a fixed tibia, moving ground plane methodology with simultaneous activation of nine extrinsic lower limb muscles. The arched foot and flatfoot models produced vertical ground reaction forces with the characteristic double-peak profile of gait, and the medial/lateral distribution of these forces compared well with the literature. The flatfoot model with implant-modified tendon transfer produced a 94.2% restoration of the medial/lateral distribution of vertical ground reaction forces generated by our arched foot model, which also represents a 2.1X improvement upon our tendon transfer model. This result demonstrates the feasibility of a pulley-like implant to improve functional outcomes for surgical treatment of adult acquired flatfoot deformity with ideal biomechanics in simulation. The real-world efficacy and feasibility of such a device will require further exploration of factors such as surgical variability, soft tissue interactions and healing response.

Arch-Support Insoles Benefit the Archery Performance and Stability of Compound Archers

The purpose of this study was to analyze the effects of the use of arch-support insoles on the archery performance and center of plantar pressure (CoP) excursion in compound archers. Fifteen highly skilled compound archers were the subjects. A pressure plate was used to measure the CoP excursion and percentage distribution of plantar pressure. The parameters were compared between archers wearing flat and arch-support insoles using a paired-sample t-test. The results demonstrated that the shooting score in archers wearing the arch-support insole was significantly greater than in those wearing the flat insoles. The CoP excursion of the left foot, right foot, and both feet in archers wearing the arch-support insole were significantly smaller than in those wearing the flat insole. The distributed percentage of the plantar pressure showed that the arch-support insole significantly reduced the plantar pressure in the left posterior zone by 3.54% compared with the flat insole, and increased the plantar pressure in the right anterior zone by 2.54%. The principal conclusion was that compound archers wearing arch-support insoles during the arrow-release process can reduce the CoP excursion of the foot and increase their shooting score. The plantar pressure was distributed evenly in arch-support insoles.

Do people with low back pain walk differently? A systematic review and meta-analysis

BACKGROUND

The biomechanics of the trunk and lower limbs during walking and running gait are frequently assessed in individuals with low back pain (LBP). Despite substantial research, it is still unclear whether consistent and generalizable changes in walking or running gait occur in association with LBP. The purpose of this systematic review was to identify whether there are differences in biomechanics during walking and running gait in individuals with acute and persistent LBP compared with back-healthy controls.

METHODS

A search was conducted in PubMed, CINAHL, SPORTDiscus, and PsycINFO in June 2019 and was repeated in December 2020. Studies were included if they reported biomechanical characteristics of individuals with and without LBP during steady-state or perturbed walking and running. Biomechanical data included spatiotemporal, kinematic, kinetic, and electromyography variables. The reporting quality and potential for bias of each study was assessed. Data were pooled where possible to compare the standardized mean differences (SMD) between back pain and back-healthy control groups.

RESULTS

Ninety-seven studies were included and reviewed. Two studies investigated acute pain and the rest investigated persistent pain. Nine studies investigated running gait. Of the studies, 20% had high reporting quality/low risk of bias. In comparison with back-healthy controls, individuals with persistent LBP walked slower (SMD = -0.59, 95% confidence interval (95%CI): -0.77 to -0.42)) and with shorter stride length (SMD = -0.38, 95%CI: -0.60 to -0.16). There were no differences in the amplitude of motion in the thoracic or lumbar spine, pelvis, or hips in individuals with LBP. During walking, coordination of motion between the thorax and the lumbar spine/pelvis was significantly more in-phase in the persistent LBP groups (SMD = -0.60, 95%CI: -0.90 to -0.30), and individuals with persistent LBP exhibited greater amplitude of activation in the paraspinal muscles (SMD = 0.52, 95%CI: 0.23-0.80). There were no consistent differences in running biomechanics between groups.

CONCLUSION

There is moderate-to-strong evidence that individuals with persistent LBP demonstrate differences in walking gait compared to back-healthy controls.

Ground reaction forces during stair ascending and descending in congenitally blind and sighted individuals

BACKGROUND

Stair ascending and descending are common in daily life activities which are challenging for blind individuals. Visual information plays an important role in controlling an individual's movements. However, the relationship between visual information and stair ascending and descending is poorly understood.

OBJECTIVE

The aim of this study was to investigate how blindness alters the ground reaction force (GRF) components during ascending and descending the stairs.

METHODS

Ten individuals with congenital blindness and 10 able-bodied sighted individuals were served as experimental (EG) and control groups (CG), respectively. The GRFs were recorded during stair ascending and descending tasks using a portable 40 × 40 cm Kistler force plate which was placed on a firm stair. CG repeated the ascending/descending tasks in both open and closed-eyes conditions. For within and between groups comparisons the repeated measure ANOVA and MANOVA tests were used, respectively. The significance level was set at p < 0.05 for all comparisons.

RESULTS

In ascending task, there was not any significant between group differences on GRF components. However, closing the eyes in CG resulted in a significant decrease in some GRF components in the stair descending (p < 0.05). The GRF components of the stair descending in CG with open and closed-eyes were significantly different from those in the blind group; however, the differences were less in closed-eyes.

SIGNIFICANCE

The GRF in the stair descent was similar in both blind and sighted individuals with closed-eyes condition, that it can increase the risk of falling in blind people. As a result, the provision of tools and equipment for the blind in descent conditions is essential.

A portable non-invasive microwave based head imaging system using compact metamaterial loaded 3D unidirectional antenna for stroke detection

A metamaterial (MTM) loaded compact three-dimensional antenna is presented for the portable, low-cost, non-invasive microwave head imaging system. The antenna has two slotted dipole elements with finite arrays of MTM unit cell and a folded parasitic patch that attains directional radiation patterns with 80% of fractional bandwidth. The operating frequency of the antenna is 1.95–4.5 GHz. The optimization of MTM unit cell is performed to increase the operational bandwidth, realized gain, and efficiency of the antenna within the frequency regime. It is also explored to improve radiation efficiency and gain when placed to head proximity. One-dimensional mathematical modelling is analyzed to precisely estimate the power distribution that validates the performance of the proposed antenna. To verify the imaging capability of the proposed system, an array of 9 antennas and a realistic three-dimensional tissue-emulating experimental semi-solid head phantom are fabricated and measured. The backscattered signal is collected from different antenna positions and processed by the updated Iterative Correction of Coherence Factor Delay-Multiply-and-Sum beamforming algorithm to reconstruct the hemorrhage images. The reconstructed images in simulation and experimental environment demonstrate the feasibility of the proposed system as a portable platform to successfully detect and locate the hemorrhages inside the brain.

Eight Weeks of Exercising on Sand Has Positive Effects on Biomechanics of Walking and Muscle Activities in Individuals with Pronated Feet: A Randomized Double-Blinded Controlled Trial

This study aimed to investigate the effects of eight weeks of barefoot running exercise on sand versus control on measures of walking kinetics and muscle activities in individuals with diagnosed pronated feet. Sixty physically active male adults with pronated feet were randomly allocated into an intervention or a waiting control group. The intervention group conducted an 8-weeks progressive barefoot running exercise program on sand (e.g., short sprints) with three weekly sessions. Pre and post intervention, participants walked at a constant speed of 1.3 m/s ± 5% on a 18 m walkway with a force plate embedded in the middle of the walkway. Results showed significant group-by-time interactions for peak impact vertical and lateral ground reaction forces. Training but not control resulted in significantly lower peak impact vertical and lateral ground reaction forces. Significant group-by-time interactions were observed for vastus lateralis activity during the loading phase. Training-induced increases were found for the vastus lateralis in the intervention but not in the control group. This study revealed that the applied exercise program is a suitable means to absorb ground reaction forces (e.g., lower impact vertical and lateral peaks) and increase activities of selected lower limb muscles (e.g., vastus lateralis) when walking on stable ground.

Discriminating features of ground reaction forces in overweight old and young adults during walking using functional principal component analysis

BACKGROUND

Limited attention has been paid to age- or body size-related changes in the ground reaction forces (GRF) during walking despite their strong associations with lower limb injuries and pathology.

RESEARCH QUESTION

Do the features of GRF during walking associate with age or body size?

METHODS

Fifty-four participants were subdivided into four groups according to their age and body size: overweight old (n = 12), non-overweight old (n = 13), overweight young (n = 13), and non-overweight young (n = 16). Participants were asked to walk at their self-selected speeds on level ground with force plates embedded in the center of walkway. Functional principal component analysis (FPCA) was performed to extract major modes of variation and functional principal component scores (FPCs) in three-dimensional GRFs. Analysis of variance models were employed to investigate the effect of age, body size, or their interactions on the FPCs of each component of the GRF, with the adjustment to gait speed.

RESULTS

Significant age and body size effects were observed in FPC1 across all three-dimensional GRF. Both overweight and older groups showed greater braking force after heel-strike and greater propulsive forces during pre-swing when compared to the non-overweight and younger groups, respectively. The overweight old group displayed greater medial forces during mid-stance and the overweight young group showed prominently larger medial forces during pre-swing, while non-overweight old showed a tendency of flatter medial-lateral GRF waveforms during the entire stance phase. FPC2 revealed that only body size had an effect on three-dimensional GRF with the highest FPC2 scores in the overweight old group.

SIGNIFICANCE

Three-dimensional GRF during walking could be altered by the body size and age, which were more pronounced in the overweight and older group. The more dynamic GRF pattern with greater and/or lower peaks could be contributing factors to the increased joint load and injury rates observed in overweight aged individuals.

Effect of textured foot orthoses on walking plantar pressure variables in children with autism spectrum disorders

The aim of this study was to evaluate the effect of textured foot orthoses on plantar pressure variables in children with autism spectrum disorders (ASDs). Thirty boys were divided into two groups based on their health status, namely: autism spectrum disorder and healthy matched controls. Plantar pressure data were captured during stance phases of shod walking with and without textured foot orthoses. Remarkably larger peak force under the toe1 and metatarsal1 and peak pressure under the toe1 and toe2-5 regions were observed in the autism group comparing with the healthy group, while lower peak force under the toe1, metatarsal1 and metatarsal2 were seen during walking with textured foot orthoses comparing with the cases of walking without them. The results showed higher values of peak pressure under metatarsal3, metatarsal4 and metatarsal5 for the textured foot orthoses walking against the cases without them. Also, analysis depicted huge reductions from pre-to-posttest for the peak pressure under toe2-5 only cases within the autism group. The reason of observing higher peak values of forces and pressures within their forefoot can potentially be their tendency to walk on their toes comparing against the healthy control children. This causes lower pressure values within all toes and the first metatarsal regions during normal walking with textured foot orthoses than walking without them. The findings revealed that the use of textured foot orthoses reduced peak pressure under toe2-5 only in the autism group. This suggests that the use of such interventions can help boys with ASDs move more safely.

Long-term training on sand changes lower limb muscle activities during running in runners with over-pronated feet

BACKGROUND

Running on sand could be a promising exercise intervention for the treatment of over-pronated feet. However, there is a lack of knowledge about the effects of running on sand on muscle activities. Therefore, this study aims to evaluate the long-term effects of running on sand on the activities of selected lower limb muscles in individuals with OPF compared with healthy controls.

METHODS

Sixty recreational adult male runners with over-pronated feet (foot posture index > 10) were divided into two equal groups (intervention and control). Participants ran barefoot at a pre-defined speed (⁓3.3 m/s) over level stable ground both before and after long-term training on the sand. Muscle activities were recorded using a surface bipolar electromyography system.

RESULTS

For the intervention group, we found a reduced foot posture index (p < 0.001; d = 2.00) and significant group-by-time interactions for gluteus medius activity during the mid-stance phase (p < 0.028; d = 0.59). Significantly higher gluteus medius activity (p = 0.028, d = 0.569) was found during the post-test. We also observed significant group-by-time interactions for medial gastrocnemius activity during the push-off phase (p < 0.041; d = 0.54). Significantly larger medial gastrocnemius activity (p = 0.041; d = 0.636) was found during the post-test compared to the pre-test.

CONCLUSIONS

Long-term running on sand resulted in reduced pronation, increased medial gastrocnemius activity, and improved frontal plane pelvic stability due to higher gluteus medius activity.

TRIAL REGISTRATION

IRCT20191211045704N1. Registered 25 February 2020. Retrospectively registered.

Effects of lumbar spinal disorders on the vertical ground reaction force and Spatio-temporal parameters in gait

BACKGROUND

Ground reaction forces are biomechanical data, providing information to investigate pathological gait. The vertical component of ground reaction force introduces the upward thrust force within gait progression. Although alterations in the vertical component in patients with spinal disorders were addressed in the literature, still the corresponding effect on spinal disorders is a major issue to scrutiny. In this study, the effects of two different anatomical spinal disorders on the vertical component pattern were investigated.

METHODS

Two groups of patients with lumbar spine stenosis and lumbar intervertebral disc degeneration with lesions at L4-L5 and/or L5-S1 levels, were recruited. The vertical component of ground reaction force and spatio-temporal parameters were obtained and analyzed using one-way analysis of variance.

FINDINGS

The results indicated that all spatio-temporal parameters differed significantly (P < 0.05) except step lengths and stride times (P > 0.05). In a similar test, the Fz2 in patients with lumbar stenosis was higher than that of those with disc degeneration (P < 0.05). Besides, the vertical ground reaction force pattern showed lower slopes in stenosis patients.

INTERPRETATION

This study showed that the vertical component of ground reaction force alterations and spatio-temporal parameters could be employed as indicators for certain spinal lesions. The results of this study could implement as an adjunct diagnostic method to help clinicians to differentiate between stenosis and disc degeneration patients and plan for their rehabilitation purposes.

Examining the efficacy of short foot exercises as an effective stand-alone treatment for mechanical low back pain associated with foot overpronation

BACKGROUND: Abnormal foot mechanics in foot over-pronation has an identified relationship with mechanical low back pain (MLBP). OBJECTIVE: To explore the use of short foot exercises (SFEs) as a standalone treatment for MLBP with foot over-pronation. METHODS: Forty-six patients with MLBP (PwMLBP) presenting with and foot over-pronation were analyzed. They were randomized into the SFE (short foot exercise), SFE plus traditional physical therapy treatment (SFE+TPT), and control (CG) groups. Functional disability and pain level were measured using the Oswestry Disability Index (ODI) and visual analog scale (VAS), respectively. Ultrasonography measured the cross-sectional area (CSA) of the abductor hallucis (AbdH) muscle. The foot posture and navicular drop (ND) were investigated using the foot posture index-6 (FPI) score and ND test, respectively. RESULTS: The CSA of the AbdH and VAS scores improved significantly (p< 0.001) between the groups, more in the SFE+TPT group than in the SFE group (p< 0.001). The ND, FPI, and ODI measures improved significantly among the groups (p< 0.001), with no significant difference (p> 0.002) between the SFE and SFE+TPT groups. The CG did not show significant differences in the outcome measures (p> 0.002). Based on the effect size, SFEs significantly improved all the variables of interest (d>1). CONCLUSION: SFEs, with or without TPT may offer an effective treatment for PwMLBP with foot over-pronation.

The Prevalence and Factors Associated with Low Back Pain Among People with Flat Feet

Background

A positive relationship between flat feet and low back pain (LBP) has not gained consensus in literature. The aim of this study was to determine the prevalence and factors associated with low back pain (acute and chronic) among individuals with flat feet.

Methods

In 2018, a cross-sectional study was conducted at a national festival in Saudi Arabia, and 1798 adult visitors were invited to participate in face-to-face interviews. Participants' characteristics were stratified by the type of foot and they were questioned on acute low back pain (ALBP) or chronic low back pain (CLBP). The odds ratio (OR) were presented as a measure of this association, followed by a multivariate analysis.

Results

The prevalence of LBP among participants with flat feet was 65.9%, among whom 51.6% suffered ALBP and 48.4% suffered from CLBP. Flat feet increased the chances of having ALBP by 3.28 times and CLBP by 4.5 times. After stratification, ALBP and CLBP were both significantly higher among all participants with flat feet in comparison with their counter groups. Multivariate analyses showed that females were more likely to complain of ALBP. Participants who did no physical activity were more likely to complain of ALBP. Female participants and older participants were more likely to complain of ALBP and CLBP.

Conclusion

Flat feet are associated with both ALBP and CLBP. Significant factors of low back pain also included sex, age, occupation, and physical activity.

Effects of Orthotic Insoles on Gait Kinematics and Low-Back Pain in Patients with Mild Leg Length Discrepancy

BACKGROUND

Mild leg length discrepancy increases biomechanical asymmetry during gait, which leads to low-back pain. Orthotic insoles with a directly integrated heel lift were used to reduce this asymmetry and thus the associated low-back pain. The aim of this study was to analyze the biomechanical adaptations of the locomotor apparatus during gait and the subjective pain ratings before and after the establishment of orthotic insole use.

METHODS

Eight patients with mild leg length discrepancy (≤2.0 cm) underwent three-dimensional biomechanical analysis while walking before and after 3 weeks of orthotic insole use. Low-back pain was assessed separately before both measurement sessions using a visual analog scale.

RESULTS

Analysis of the kinematic parameters highlighted individual adaptations. The symmetry index of Dingwell indicated that orthotic insoles had no significant effect on the kinematic gait parameters and an unpredictable effect across patients. Orthotic insole use significantly and systematically (in all of the patients) reduced low-back pain (P < .05), which was correlated with changes in ankle kinematics (P = .02, r = 0.80).

CONCLUSIONS

The effects of orthotic insoles on gait symmetry are unpredictable and specific to each patient's individual manner of biomechanical compensation. The reduction in low-back pain seems to be associated with the improved ankle kinematics during gait.

An Endurance-Dominated Exercise Program Improves Maximum Oxygen Consumption, Ground Reaction Forces, and Muscle Activities in Patients With Moderate Diabetic Neuropathy

Background

The prevalence of diabetes worldwide is predicted to increase from 2.8% in 2000 to 4.4% in 2030. Diabetic neuropathy (DN) is associated with damage to nerve glial cells, their axons, and endothelial cells leading to impaired function and mobility.

Objective

We aimed to examine the effects of an endurance-dominated exercise program on maximum oxygen consumption (VO₂max), ground reaction forces, and muscle activities during walking in patients with moderate DN.

Methods

Sixty male and female individuals aged 45–65 years with DN were randomly assigned to an intervention (IG, n = 30) or a waiting control (CON, n = 30) group. The research protocol of this study was registered with the Local Clinical Trial Organization (IRCT20200201046326N1). IG conducted an endurance-dominated exercise program including exercises on a bike ergometer and gait therapy. The progressive intervention program lasted 12 weeks with three sessions per week, each 40–55 min. CON received the same treatment as IG after the post-tests. Pre- and post-training, VO₂max was tested during a graded exercise test using spiroergometry. In addition, ground reaction forces and lower limbs muscle activities were recorded while walking at a constant speed of ∼1 m/s.

Results

No statistically significant baseline between group differences was observed for all analyzed variables. Significant group-by-time interactions were found for VO₂max (p < 0.001; d = 1.22). The post-hoc test revealed a significant increase in IG (p < 0.001; d = 1.88) but not CON. Significant group-by-time interactions were observed for peak lateral and vertical ground reaction forces during heel contact and peak vertical ground reaction force during push-off (p = 0.001–0.037; d = 0.56–1.53). For IG, post-hoc analyses showed decreases in peak lateral (p < 0.001; d = 1.33) and vertical (p = 0.004; d = 0.55) ground reaction forces during heel contact and increases in peak vertical ground reaction force during push-off (p < 0.001; d = 0.92). In terms of muscle activity, significant group-by-time interactions were found for vastus lateralis and gluteus medius during the loading phase and for vastus medialis during the mid-stance phase, and gastrocnemius medialis during the push-off phase (p = 0.001–0.044; d = 0.54–0.81). Post-hoc tests indicated significant intervention-related increases in vastus lateralis (p = 0.001; d = 1.08) and gluteus medius (p = 0.008; d = 0.67) during the loading phase and vastus medialis activity during mid-stance (p = 0.001; d = 0.86). In addition, post-hoc tests showed decreases in gastrocnemius medialis during the push-off phase in IG only (p < 0.001; d = 1.28).

Conclusions

This study demonstrated that an endurance-dominated exercise program has the potential to improve VO₂max and diabetes-related abnormal gait in patients with DN. The observed decreases in peak vertical ground reaction force during the heel contact of walking could be due to increased vastus lateralis and gluteus medius activities during the loading phase. Accordingly, we recommend to implement endurance-dominated exercise programs in type 2 diabetic patients because it is feasible, safe and effective by improving aerobic capacity and gait characteristics.

Effects of an elastic resistance band exercise program on kinetics and muscle activities during walking in young adults with genu valgus: A double-blinded randomized controlled trial

BACKGROUND

This double-blinded randomized-controlled-trial aimed to identify the effects of an elastic band resistance training on walking kinetics and muscle activities in young adults with genu valgus.

METHODS

Forty-two male young adults aged 22.5(2.7) years with genu valgus were randomly allocated to two experimental groups. The intervention group (n = 21) conducted a 14-weeks elastic band resistance training. The control group was passive during the intervention period and received the same treatment after the post-tests. Pre and post training, ground reaction forces and lower limb muscle activities were recorded during walking.

FINDINGS

Results revealed significant group-by-time interactions for peak medial ground reaction force and time-to-peak for posterior ground reaction force in favor of the intervention group (p < 0.012; d = 0.83-3.76). Resistance training with elastic bands resulted in significantly larger peak medial ground reaction force (p < 0.001; d = 1.45) and longer time-to-peak for posterior ground reaction force (p < 0.001; d = 1.85). Finding showed significant group-by-time interactions for peak positive free moment amplitudes in favor of the intervention group (p < 0.001; d = 1.18-2.02). Resistance training resulted in a lower peak positive free moment amplitude (p = 0.001; d = 1.46). With regards to muscle activities, the analysis revealed significant group-by-time interactions for rectus femoris and gluteus medius activities during the push-off phase in favor of the intervention group (p < 0.038; d = 0.68-0.89). Resistance training induced higher rectus femoris (p = 0.038; d = 0.84) and gluteus medius (p = 0.007; d = 0.54) activities.

INTERPRETATION

This study proved the effectiveness of resistance training using elastic bands on kinetics and muscle activities during walking in male adults with genu valgus disorder. Given that this training regime is low cost, effective, and easy-to-administer, we suggest that it should be implemented as a rehabilitative or preventive means for young adults with genu valgus.

The impact of hearing loss on three-dimensional lower limb joint torques during walking in prepubertal boys

INTRODUCTION

In children, the impact of hearing loss on biomechanical gait parameters is not well understood. Thus, the objectives of this study were to examine three-dimensional lower limb joint torques in deaf compared to age-matched healthy (hearing) children while walking at preferred gait speed.

METHODS

Thirty prepubertal boys aged 8-14 were enrolled in this study and divided into a group with hearing loss (deaf group) and an age-matched healthy control. Three-dimensional joint torques were analyzed during barefoot walking at preferred speed using Kistler force plates and a Vicon motion capture system.

RESULTS

Findings revealed that boys with hearing loss showed lower joint torques in ankle evertors, knee flexors, abductors and internal rotators as well as in hip internal rotators in both, the dominant and non-dominant lower limbs (all p < 0.05; d = 1.23-7.00; 14-79%). Further, in the dominant limb, larger peak ankle dorsiflexor (p < 0.001; d = 1.83; 129%), knee adductor (p < 0.001; d = 3.20; 800%), and hip adductor torques (p < 0.001; d = 2.62; 350%) were found in deaf participants compared with controls.

CONCLUSION

The observed altered lower limb torques during walking are indicative of unstable gait in children with hearing loss. More research is needed to elucidate whether physical training (e.g., balance and/or gait training) has the potential to improve walking performance in this patient group.

Predicting foot orthosis deformation based on its contour kinematics during walking

BACKGROUND

Customized foot orthoses (FOs) are designed based on foot posture and function, while the interaction between these metrics and FO deformation remains unknown due to technical problems. Our aim was to predict FO deformation under dynamic loading using an artificial intelligence (AI) approach, and to report the deformation of two FOs of different stiffness during walking.

METHODS

Each FO was fixed on a plate, and six triad reflective markers were fitted on its contour, and 55 markers on its plantar surface. Manual loadings with known magnitude and application point were applied to deform "sport" and "regular" (stiffer) FOs in all regions (training session). Then, 13 healthy male subjects walked with the same FOs inside shoes, where the triad markers were visible by means of shoe holes (walking session). The marker trajectories were recorded using optoelectronic system. A neural network was trained to find the dependency between the orientation of triads on FO contour and the position of markers on its plantar surface. After tuning hyperparameters and evaluating the performance of the model, marker positions on FOs surfaces were predicted during walking for each subject. Statistical parametric mapping was used to compare the pattern of deformation between two FOs.

RESULTS

Overall, the model showed an average error of <0.6 mm for predicting the marker positions on both FOs. The training setup was appropriate to simulate the range of triads' displacement and the peak loading on FOs during walking. Sport FO showed different pattern and significantly higher range of deformation during walking compared to regular FO.

CONCLUSION

Our technique enables an indirect and accurate estimation of FO surface deformation during walking. The AI model was capable to make a distinction between two FOs with different stiffness and between subjects. This innovative approach can help to optimally customize the FO design.

A Systematic Approach to the Design and Characterization of A Smart Insole for Detecting Vertical Ground Reaction Force (vGRF) in Gait Analysis

Gait analysis is a systematic study of human locomotion, which can be utilized in various applications, such as rehabilitation, clinical diagnostics and sports activities. The various limitations such as cost, non-portability, long setup time, post-processing time etc., of the current gait analysis techniques have made them unfeasible for individual use. This led to an increase in research interest in developing smart insoles where wearable sensors can be employed to detect vertical ground reaction forces (vGRF) and other gait variables. Smart insoles are flexible, portable and comfortable for gait analysis, and can monitor plantar pressure frequently through embedded sensors that convert the applied pressure to an electrical signal that can be displayed and analyzed further. Several research teams are still working to improve the insoles’ features such as size, sensitivity of insoles sensors, durability, and the intelligence of insoles to monitor and control subjects’ gait by detecting various complications providing recommendation to enhance walking performance. Even though systematic sensor calibration approaches have been followed by different teams to calibrate insoles’ sensor, expensive calibration devices were used for calibration such as universal testing machines or infrared motion capture cameras equipped in motion analysis labs. This paper provides a systematic design and characterization procedure for three different pressure sensors: force-sensitive resistors (FSRs), ceramic piezoelectric sensors, and flexible piezoelectric sensors that can be used for detecting vGRF using a smart insole. A simple calibration method based on a load cell is presented as an alternative to the expensive calibration techniques. In addition, to evaluate the performance of the different sensors as a component for the smart insole, the acquired vGRF from different insoles were used to compare them. The results showed that the FSR is the most effective sensor among the three sensors for smart insole applications, whereas the piezoelectric sensors can be utilized in detecting the start and end of the gait cycle. This study will be useful for any research group in replicating the design of a customized smart insole for gait analysis.

Effect of a corrective exercise program on gait kinetics and muscle activities in older adults with both low back pain and pronated feet: A double-blind, randomized controlled trial

BACKGROUND

Low back pain is among the most common health problems seen in primary care. This study aimed to evaluate the effect of a corrective exercise program on GRF components, back pain, disability score, and muscle activities in back pain patients with pronated feet during walking.

RESEARCH QUESTION

What is the effect of corrective exercise program on gait kinetics, back pain, disability score, and muscle activities in back pain patients with pronated feet during walking?

METHODS

Thirty-six older adults with both back pain and pronated feet volunteered to participate in this study. They were randomly divided into two equal groups (experimental and control groups). Kinetic and EMG data were recorded during both pre and posttest. Visual analog pain scale and Roland-Morris disability questionnaire were used to assess back pain and disability values, respectively.

RESULTS

In the experimental group but not in the control group, walking speed was significantly increased from pre to posttest (p = 0.001). The loading rate and free moment values were similar during both the pre and posttest (p > 0.05). In the experimental group but not in the control group, the disability score, back pain, tibialis anterior activity, and rectus abdominis activity were decreased during the posttest than that in the pretest (p < 0.001).

SIGNIFICANCE

Higher walking speed, lower muscle activity and pain, lower disability score along with similar loading rate and free moments in the experimental group compared with the control group after the training protocol demonstrate the improvement of gait efficiency.

Pediatric Flatfeet-A Disease Entity That Demands Greater Attention and Treatment

Background: Pediatric flatfoot is a common deformity. Unfortunately, the common opinion has been that most children with this faulty foot structure will simply out-grow it, despite no radiographic evidence to support this claim. Every step on a deformed foot leads to excessive tissue strain and further joint damage. Many forms of conservative and surgical treatments have been offered. This study was aimed at investigating the effectiveness of non-surgical and surgical treatment options. Main Text: faulty-foot structure is the leading cause of many secondary orthopedic deformities. A wide range of treatments for pediatric flatfeet have been recommended from the "do-nothing" approach, observation, to irreversible reconstructive surgery. Most forms of conservative care lack evidence of osseous realignment and stability. A conservative surgical option of extra-osseous talotarsal joint stabilization provides patients an effective form of treatment without the complications associated with other irreversible surgical procedures. Conclusion: Pediatric flatfeet should not be ignored or downplayed. The sooner effective treatment is prescribed, the less damage will occur to other parts of the body. When possible, a more conservative corrective procedure should be performed prior to irreversible, joint destructive options.

Ground reaction forces and muscle activity while walking on sand versus stable ground in individuals with pronated feet compared with healthy controls

BACKGROUND

Sand is an easy-to-access, cost-free resource that can be used to treat pronated feet (PF). Therefore, the aims of this study were to contrast the effects of walking on stable ground versus walking on sand on ground reaction forces (GRFs) and electromyographic (EMG) activity of selected lower limb muscles in PF individuals compared with healthy controls.

METHODS

Twenty-nine controls aged 22.2±2.5 years and 30 PF individuals aged 22.2±1.9 years were enrolled in this study. Participants walked at preferred speed and in randomized order over level ground and sand. A force plate was included in the walkway to collect GRFs. Muscle activities were recorded using EMG system.

RESULTS

No statistically significant between-group differences were found in preferred walking speed when walking on stable ground (PF: 1.33±0.12 m/s; controls: 1.35±0.14 m/s; p = 0.575; d = 0.15) and sand (PF: 1.19±0.11 m/s; controls: 1.23±0.18 m/s; p = 0.416; d = 0.27). Irrespective of the group, walking on sand (1.21±0.15 m/s) resulted in significantly lower gait speed compared with stable ground walking (1.34±0.13 m/s) (p<0.001; d = 0.93). Significant main effects of "surface" were found for peak posterior GRFs at heel contact, time to peak for peak lateral GRFs at heel contact, and peak anterior GRFs during push-off (p<0.044; d = 0.27-0.94). Pair-wise comparisons revealed significantly smaller peak posterior GRFs at heel contact (p = 0.005; d = 1.17), smaller peak anterior GRFs during push-off (p = 0.001; d = 1.14), and time to peak for peak lateral GRFs (p = 0.044; d = 0.28) when walking on sand. No significant main effects of "group" were observed for peak GRFs and their time to peak (p>0.05; d = 0.06-1.60). We could not find any significant group by surface interactions for peak GRFs and their time to peak. Significant main effects of "surface" were detected for anterior-posterior impulse and peak positive free moment amplitude (p<0.048; d = 0.54-0.71). Pair-wise comparisons revealed a significantly larger peak positive free moment amplitude (p = 0.010; d = 0.71) and a lower anterior-posterior impulse (p = 0.048; d = 0.38) when walking on sand. We observed significant main effects of "group" for the variable loading rate (p<0.030; d = 0.59). Pair-wise comparisons revealed significantly lower loading rates in PF compared with controls (p = 0.030; d = 0.61). Significant group by surface interactions were observed for the parameter peak positive free moment amplitude (p<0.030; d = 0.59). PF individuals exhibited a significantly lower peak positive free moment amplitude (p = 0.030, d = 0.41) when walking on sand. With regards to EMG, no significant main effects of "surface", main effects of "group", and group by surface interactions were observed for the recorded muscles during the loading and push-off phases (p>0.05; d = 0.00-0.53).

CONCLUSIONS

The observed lower velocities during walking on sand compared with stable ground were accompanied by lower peak positive free moments during the push-off phase and loading rates during the loading phase. Our findings of similar lower limb muscle activities during walking on sand compared with stable ground in PF together with lower free moment amplitudes, vertical loading rates, and lower walking velocities on sand may indicate more relative muscle activity on sand compared with stable ground. This needs to be verified in future studies.

The effect of time restricted visual sensory input on asymmetry of ground reaction force components in female children

The association between visual sensory and the asymmetry index of sit-to-stand ground reaction force characteristics is not fully understood. Therefore, the purpose of this study was to investigate asymmetry index of sit-to-stand ground reaction forces, their times-to-peak, vertical loading rate, impulses, and free moment in blind and sighted children. 15 female children with congenital blindness and 30 healthy girls with no visual impairments volunteered to participate in this study. The girls with congenital blindness were placed in one group and the girls with no visual impairments were randomly divided into two groups of 15. The two condition groups consisted of, one eyes open and the other, eyes closed. The participants in the eyes closed group were asked to close their eyes for 20 min before the test, whereas those in the eyes open group kept their eyes open. Kinematic and kinetic data were collected using an eight-camera motion analysis system synchronized with two force plates embedded in the floor. A MANOVA test was run for between-group comparisons. There were no distinctive biomechanical alternations in all axes of ground reaction forces and their times-to-peak, vertical loading rate, impulses and free moments in congenital blindness and eyes closed groups compared with the eyes open group. However, eyes closed was associated with increased total time and second phase duration of sit-to-stand performance by 69% (p = 0.008) and 62% (p = 0.008), respectively. These findings reveal that individuals who are visually restricted in the short term, do not develop stereotypical movement strategies for sit-to-stand.

Effect produced on ground reaction forces by a prefabricated, weight-bearing and non-weight-bearing foot orthosis in the treatment of pronated foot: Pilot study

BACKGROUND

The aim of this study is to explore the changes in ground reaction force (GRF) produced by custom-made weight-bearing and nonweight-bearing foot orthoses and by a prefabricated foot orthosis, in the control of the pronated foot.

METHODS

Thirty-nine participants were recruited. All were in good health, aged 18 to 25 years, and presented pronated foot. Three different types of foot orthosis were studied: prefabricated, weight-bearing, and nonweight-bearing.

RESULTS

No significant differences were observed in the phases of the gait cycle between the prefabricated, the weight-bearing, and the nonweight-bearing foot orthoses.

CONCLUSIONS

Neither prefabricated insoles nor custom-made orthoses (weight-bearing or nonweight-bearing) modified GRF.

Sit-to-stand ground reaction force characteristics in blind and sighted female children

BACKGROUND

The association between visual sensory and sit-to-stand ground reaction force characteristics is not clear. Impulse is the amount of force applied over a period of time. Also, free moment represents the vertical moment applied in the center of pressure (COP).

RESEARCH QUESTION

How the ground reaction force components, vertical loading rate, impulses and free moment respond to long and short term restricted visual information?

METHODS

Fifteen female children with congenital blindness and 45 healthy girls with no visual impairments participated in this study. The girls with congenital blindness were placed in one group and the 45 girls with no visual impairments were randomly divided into three groups of 15; eyes open, permanently eyes closed, and temporary eyes closed. The participants in the permanently eyes closed group closed their eyes for 20 min before the test, whereas temporary eyes closed group did tests with their eyes closed throughout, and those in the eyes open group kept their eyes open.

RESULTS

Congenital blindness was associated with increased vertical loading rate, range of motion of knee and hip in the medio-lateral plane. Also, medio-lateral and vertical ground reaction force impulses. Similar peak negative and positive free moments were observed in three groups.

SIGNIFICANCE

In conclusion, the results reveal that sit-to-stand ground reaction force components in blind children may have clinical importance for improvement of balance control of these individuals.

Low back pain and disability in individuals with plantar heel pain

BACKGROUND

Lack of response to plantar heel pain (PHP) treatment may be related to unmanaged low back pain (LBP) and low back dysfunction, but a relationship between LBP and PHP has not been established. The purpose of this investigation was to compare the prevalence of LBP among individuals with and without PHP and to assess the association between low back disability and foot/ankle function.

METHODS

A cross-sectional study compared the prevalence and likelihood of LBP in individuals with (n=27) and without (n=27) PHP matched to age, sex, BMI, foot posture, and foot mobility. In individuals with PHP, correlations were examined between foot/ankle function using the foot and ankle ability measure (FAAM), low back disability using the Oswestry low back disability questionnaire (OSW), duration of PHP symptoms, body mass index (BMI), and age.

RESULTS

A greater percentage of individuals with PHP had LBP (74% versus 37% of controls, odds ratio=5.2, P=0.009) and higher levels of low back disability (17% higher OSW score than controls, P<0.001). In individuals with PHP, FAAM scores were correlated with OSW scores (ρ=-0.463, P=0.015), but not with duration of PHP symptoms, BMI, or age (P>0.150).

CONCLUSIONS

Individuals with PHP had a greater prevalence of LBP and higher low back disability that was correlated to reduced foot and ankle function. Treatment to address both local and proximal impairments, including impairments related to LBP, may be warranted to improve the management of PHP.

The effects of low arched feet on lower limb joints moment asymmetry during gait in children: A cross sectional study

BACKGROUND

The prevalence of flexible flat feet in children was reported to be up to 20% in previous studies. However, the role of foot type in the development of musculoskeletal injuries is less clear, particularly in children. The purpose of this study was to investigate the differences in the joint moment asymmetry in children with flexible flat feet and healthy matched control subjects.

METHODS

Fourteen male children with flexible flat feet and 15 healthy control subjects served as the sample of the study. Three dimensional kinematics and kinetic data were collected using a Vicon camera system and two Kistler force platforms during walking. Then between-limb asymmetry was examined for each joint moment.

RESULTS

Normal individuals experienced higher asymmetry in the ankle eversion and the external rotation moments than the flat feet group. Asymmetry indices in the knee abduction, adduction, and the internal rotation moments in the flat feet group were higher than that in the normal group by 15%, 24% and 13%, respectively. Furthermore, in comparison of the two groups, individuals with flat feet had higher asymmetry in the hip flexion moment as well as the hip abduction moment.

CONCLUSIONS

In order to provide appropriate protocols or footwear design for male children with flat feet, clinicians need to understand that flat feet children do not have higher levels of joint moment asymmetry as compared to normal children in all joints and all planes; consequently, they must differentiate their treatments for each specific joint. However, further larger study is warranted.

Rehabilitation improves walking kinematics in children with a knee varus: Randomized controlled trial

BACKGROUND

Previous studies have demonstrated increased medial stresses in knee varus alignment. Selecting a suitable treatment strategy for individuals with knee malalignment should be a priority.

OBJECTIVES

We aimed to investigate the effects of a 16-week corrective exercise continuum (CEC) program on 3-D joint angles of the dominant and non-dominant lower limbs in children with genu varus during walking.

METHODS

Overall, 28 male children with genu varus (age range 9-14 years) volunteered to participate in this study. They were randomly divided into 2 equal groups (experimental and control). The participants of the experimental group received CEC for 16 weeks. 3-D gait analysis involved using a Vicon Motion System. Paired and independent sample t-tests were used for within- and between-group comparisons, respectively.

RESULTS

For the experimental group, comparison of pre- and post-test joint kinematics of the dominant lower limb revealed that CEC decreased the peak ankle dorsiflexion angle by 26% (P=0.020), peak foot internal rotation angle by 53% (P=0.001), peak knee internal rotation angle by 40% (P=0.011), peak hip abduction by 47% (P=0.010), and peak hip external rotation angle by 60% (P=0.001). In contrast, peak knee external rotation angle of the dominant limb was increased after the training program by 46% (P=0.044). For the non-dominant lower limb, CEC decreased the peak ankle inversion by 63% (P<0.01), peak ankle eversion by 91% (P<0.01), peak foot internal rotation by 50% (P<0.01), peak knee internal rotation by 29%; P=0.042), peak hip abduction angle by 38% (P<0.01), and peak hip external rotation angle by 60% (P<0.01).

CONCLUSIONS

CEC therapy reduced excessive foot and knee internal rotations as well as excessive hip external rotation during walking in children with genu varus.

Muscle activity and kinetics of lower limbs during walking in pronated feet individuals with and without low back pain

The objectives of this study were to investigate whether excessive feet pronation alters the joints' kinematics, kinetics and the activity of involved muscles during gait in low back pain patients.

METHODS

The lower limb joints' motion, moment and power, as well as the activity of involved muscles during walking were measured in a control group, and two experimental groups including a group with excessive feet pronation only, and another group of low back pain patients with excessive feet pronation.

RESULTS

In both experimental groups, ankle inversion, knee flexion and internal rotation, hip internal rotation, plantar flexors' moment, hip flexors' moment, and peak positive ankle power were lower than those in control group (p < .05). Besides, in patients, higher activity of gastrocnemius medialis, gluteus medius, erector spinae, and internal oblique muscles, and lower negative power at the ankle and peak positive power at the knee were observed (p < .05). In conclusion, pronated feet with low back pain was associated with less ankle inversion and knee flexion, higher knee and hip internal rotation, higher muscle activity, less energy absorption at the ankle, and reduced positive power at the knee. This study reveals that strengthening of the muscles especially knee extensors are of great importance in low back pain patients with feet pronation.

Combining valgus knee brace and lateral foot wedges reduces external forces and moments in osteoarthritis patients

Osteoarthritis progression can be related to the external knee adduction and flexion moments during walking. Lateral foot wedges and knee braces have been used as treatment for osteoarthritis, but little is known about their influence on knee joint moments generated in the sagittal and frontal planes. Therefore, the aim of the present study was determine the effects of the isolated and combined use of valgus knee brace and lateral wedge foot orthotic on peak forces and moments during gait in knee osteoarthritis patients. Twenty four males (age: 62.1±2.0years) with varus alignment, symptomatic medial compartment knee osteoarthritis participated in this study. Subjects walked over ground at preferred speed in four conditions: (1) no assistive device (control); (2) using lateral wedges, (3) using knee braces, and (4) using both lateral wedges and knee braces. Ground reaction forces (GRF) and moments, as well as lower limb kinematics were recorded. Peak GRF, vertical loading rate, free moment, external knee adduction and flexion moments were compared across conditions. The concurrent use of lateral wedge and knee brace reduced the first peak GRF in the vertical (6%, p=0.002), anterior-posterior (30%, p=0.028) and medial-lateral directions (44%, p=0.029). Moreover, the use of these devices reduced the peak external knee adduction moment (25%, p=0.019), but not the external flexion moment and free moment (p>0.05). The combined use of lateral wedges and knee braces can reduce medial-lateral knee joint loading, but despite reduced peak forces in the sagittal plane, these device do not reduce joint moments.

Do different methods for measuring joint moment asymmetry give the same results?

Gait asymmetry is defined as a loss of perfect agreement between the dominant and non-dominant lower limbs. Conflicting results from gait asymmetry studies may be due to different definitions of asymmetry, different research methods, and/or different variables and formulas used for asymmetry calculation. As a result, this makes it difficult to compare joint asymmetry values between studies. An accurate and precise understanding of asymmetry during human walking is an important step towards developing enhanced rehabilitation protocols for pathological gait. This study examined bilateral lower extremity joint moment asymmetry during the stance phase of walking using three different methods. Fourteen male children (with flat feet) aged 8-14 years participated in this study. The three-dimensional lower limb kinetics was evaluated during a comfortable gait. Then, right and left lower limb joint moments were used to calculate the joint moment asymmetry via three different methods (Lathrop-Lambach method: equation used by Lathrop-Lambach et al. (2014); Su method: equation used by Su et al. (2015); Nigg method: equation used by Nigg et al. (2013)). Repeated-measures ANOVAs (α = 0.05) were used to compare the values of net joint moment asymmetry calculated by the three methods. The results of the statistical analyses found that the amounts of moment symmetry between limbs calculated by the first two methods were significantly greater than that of using the Nigg method (except for the values of the frontal ankle moment computed by the Lathrop-Lambach method). Furthermore, in comparison of the first two methods, using the Su method showed a reduction in moment asymmetry for all joints and for all moments (p < 0.05). We conclude that, although all of three common methods for determining asymmetry between limbs have documented merit, they sometimes differ dramatically in results.

Effect of kinesio taping on lower limb joint powers in individuals with genu varum

OBJECTIVE

Therapeutic lateral knee joint muscle taping potentially offers a low-risk, economical and effective alternative for the clinical treatment of light to moderate knee overload, due to misalignment in patients with genu varum. In this study, we aimed at investigating the immediate effect of lateral knee joint muscular kinesio taping on lower limb joint powers, during the stance phase of walking, in individuals with genu varum.

METHODS

Fifteen male subjects with genu varum misalignment (age: 24.2±3.7 years) participated in the study. Subjects performed three walking trials without, and three with, biceps femoris and vastus lateralis kinesio taping. The three-dimensional position coordinate data of reflective markers were collected at 100 Hz using a six-cameras Vicon system (Motion Analysis Corp., UK). Additionally, two Kistler force plates (Kistler AG, Winterthur, Switzerland) were used to record the Ground Reaction Forces (GRF) components at 1000 Hz during stance phase of walking. A three-way ANOVA with post-hoc testing (using paired samples Student's t-test with Bonferroni correction) was performed to compare the power values of lower limb joints before and after the use of KT.

RESULTS

With kinesio taping, we observed that the average negative power increased at the ankle level in dominant limb, (P<0.05, 10-20% of gait cycle, GC), and at the knee level in both limbs (10-20% and 60-80% GC). Further, average negative power of the non-dominant knee joint (80-100% GC) and positive power of the non-dominant hip joint (60-80% GC) significantly reduced (P<0.05) in kinesio taping condition.

CONCLUSION

The biomechanical analysis of joint power during walking using kinesio taping provided essential information about the possible mechanisms involved in gait analysis with this intervention in adults with genu varus.

The effect of foot orthoses on joint moment asymmetry in male children with flexible flat feet

INTRODUCTION

It has been widely postulated that structural and functional misalignments of the foot, such as flat foot, may cause mechanical deviations of the lower limb during walking. The aim of this study was to investigate the effect of foot orthoses on lower extremity joint moment asymmetry during the stance phase of walking in children with asymptomatic flexible flat feet.

METHODS

Fourteen volunteer male children, clinically diagnosed with flexible flat feet, participated in this study. Subjects completed 12 walking trials at a self-selected walking speed while 3-dimensional kinematic and kinetic data were collected for two conditions: shod with no orthoses, and shod with orthoses. The gait asymmetry index for each variable for each subject was defined as: (1-(lesser moment/greater moment)) × 100.

RESULTS

Results reveal no significant differences in ankle or knee joint moment asymmetry. However, the use of foot orthoses decreased asymmetry for the hip abduction moment (P = 0.04) compared to walking without orthoses and also resulted in subtle, non-significant increases in frontal plane subtalar and sagittal plane knee and hip joints moment asymmetry.

CONCLUSION

We conclude that foot orthoses decrease frontal plane hip joint moment asymmetry, but have little effect on ankle and knee joint asymmetry.

Gait ground reaction force characteristics in deaf and hearing children

The link between gait parameters and hearing loss is not well understood. The objective of this study was to investigate the effects of the gait ground reaction forces, their time to peak, vertical loading rate, impulses and free moment during gait in deaf and hearing children. Thirty male children were equally divided into a healthy group and a group with hearing loss problems (Deaf group). Ground reaction forces were analyzed during barefoot walking. MANOVA test was used for between group comparisons. The significance level was set at p<0.05 for all analyses. Hearing loss was associated with increased propulsion lateral-medial ground reaction force (p=0.031), its time to peak (p=0.008), and lateral- medial impulse (p=0.018). Similar vertical reaction forces were observed in both groups (p>0.05). Positive peak of free moments in the healthy group was significantly greater than that in the deaf group (p=0.004). In conclusion, the results reveal that gait ground reaction force components in deaf children may have clinical values for rehabilitation of these subjects.