The Māori foot exhibits differences in plantar loading and midfoot morphology to the Caucasian foot

The question being addressed in the current study was whether the diabetic Māori foot was more or less prone to ulceration than the diabetic New Zealand Caucasian (NZC) foot. Harris mat and pedobarographic analyses were employed to assess static and dynamic foot morphology and plantar loading in 40 Māori and NZC diabetic and non-diabetic participants. Significantly higher peak pressures were exhibited by the diabetic Māori participants compared to their NZC peers at the central forefoot. Significantly higher static and dynamic arch index values and significantly higher sub-arch angle values were exhibited by the non-diabetic Māori participants compared to their NZC peers. The latter findings suggest that healthy Māori may have a predisposition towards having a flatter foot than healthy NZC, which may have footwear design implications.     

Is Achilles tendon blood flow related to foot pronation?

In the etiology of Achilles tendinopathy (AT), it is frequently suggested that excessive pronation causes a vascular constriction of the Achilles tendon, described as the “whipping phenomenon” (Clement et al., 1984). Although previous studies focused on the association between pronation and AT, it is striking that the underlying association between foot pronation and blood flow has not been studied yet. Therefore, the aim of this study was to investigate whether the amount of pronation during running influences the Achilles tendon blood flow. Twenty‐five experienced runners, aged 34.5±10.2 years, participated in this study. 2D‐lower limb kinematics during barefoot and shod running in both frontal and sagittal plane were assessed. Blood flow of the Achilles tendon was measured before and after barefoot and shod running, using the oxygen‐to‐see device. The results of this study showed a significant effect of eversion excursion on the increase in Achilles tendon blood flow after shod running. More specifically, the more the eversion excursion observed, the lower the increase in blood flow (P=.013). We therefore suggest, in individuals with increased inversion at touchdown and increased eversion around midstance during shod running, that antipronation measures could be useful in both preventing and managing Achilles tendinopathy.     

Body on the beach…a case of foot and mouth?

The case of a missing person is described whose body was discovered almost 8 months later on a secluded beach on the Solway coast, south west Scotland. The delay in discovery was due to the foot and mouth outbreak in the UK in 2001 and this resulted in conditions favouring the development of partial mummification. The influence of the tides and involvement of HM Coastguard are discussed, along with difficulties in the identification of partially skeletonised remains.     

Can orthoses and navicular drop affect foot motion patterns during running?

ObjectivesThe purpose of this study was to examine the influence of semi-rigid foot orthoses on forefoot–rearfoot joint coupling patterns in individuals with different navicular drop measures during heel–toe running.DesignTen trials were collected from twenty-three male subjects who ran slowly shod at 170 steps per minute (2.23 m/s) with a semi-rigid orthoses and without.MethodsForefoot–rearfoot coupling motions were assessed using a vector coding technique during four intervals across the first 50% of stance. Subjects were divided into two groups based on navicular drop measures. A three way ANOVA was performed to examine the interaction and main effects of stance interval, orthoses condition and navicular drop (p < 0.05).ResultsThere were no interaction effects among stance interval, orthoses condition, or navicular drop (p = 0.14) whereas an interaction effect of orthoses condition and stance interval was observed (p = 0.01; effect size = 0.74). Forefoot–rearfoot coupling motion in the no-orthoses condition increased from heel-strike to foot-flat phase at a rate faster than the orthoses condition (p = 0.02).ConclusionsFoot orthoses significantly decrease the forefoot–rearfoot joint coupling angle by reducing forefoot frontal plane motion relative to the rearfoot. Navicular drop measures did not influence joint coupling relationships between the forefoot and rearfoot during the first 50% of stance regardless of orthotic condition.     

Bone marrow edema syndrome of the foot: one year follow-up with MR imaging

OBJECTIVE: To describe the MR findings of bone marrow edema syndrome (BMES) of the foot and its evolution at 1 year follow-up. DESIGN AND PATIENTS: Twenty-five of 32 patients with disabling foot and ankle pain unrelated to trauma diagnosed as BMES when MR imaging demonstrated a bone marrow edema pattern in one or more bones without any radiological or underlying clinical cause, were re-evaluated by MR imaging 1 year later. RESULTS: On the initial MR examinations an average of 4.7 individual bones were involved by bone marrow edema. Soft tissue edema was present in every patient and joint effusion in 10 patients. MR imaging at 1 year showed resolution of bone edema in 18 patients (72%), partial improvement in five (20%) and no improvement in two (8%). Six patients (24%) developed similar symptoms in the other foot during follow-up. Ten of 17 available plain radiographs showed some loss of radiodensity. Further bone marrow edema developed in bones of the same foot that were initially normal, or in uninvolved distant bone marrow areas in the same affected bone, in six of seven patients on follow-up MR imaging. CONCLUSIONS: The evolution of the MR findings of BMES of the foot is to complete resolution or partial improvement at 1 year in the majority of cases. Migration to the other foot occurs in up to a quarter of patients.     

Are in-shoe pressure characteristics in symptomatic idiopathic pes cavus related to the location of foot pain?

People who have extremely high arched feet may be subject to substantial levels of foot pain, despite the lack of obvious pathology. This study sought to investigate the effect of pes cavus on pain intensity and location and on the magnitude and distribution of foot pressure. Measurements were derived from the more symptomatic foot of 130 participants with painful, idiopathic pes cavus. Data were collected using Pedar in-shoe pressure sensors and averaged over nine randomly selected steps. Participant information, including location and intensity of pain, Foot Posture Index values and anthropometric and "quality of life" variables, were also recorded. Painful idiopathic pes cavus seems to provoke a more cautious gait pattern than normal, with reduced peak and mean pressure values, particularly in the fore- and rear-foot regions. In particular, participants with pain confined to the rear-foot exhibit an antalgic gait pattern, with lower pressure values and a longer period of foot-ground contact in the heel region than those with pain only in the fore-foot. We determined no clear predictors of pain in terms of foot posture or demographics, although people with high body mass index values are more likely to have pain in several regions. The relationship between the posture of the foot and the presentation of pain remains unclear, however we believe that the presence of heel pain in pes cavus may be more restricting than fore-foot pain.     

Assessment of the test–retest reliability of a foot placement accuracy protocol in assisted-living older adults

IntroductionThis study assessed the test–retest reliability of a foot placement accuracy protocol in a population of assisted-living elderly. The goal was to evaluate the execution of foot placement performance with increasing complexity of the walking condition.MethodsTwenty-five elderly participants (5 males, 20 females, 80.4 ± 8.6 years) were assessed by one observer in two sessions with 48 h between the measurements. Participants walked at self-selected pace along a pathway with three different walking conditions composed of two rectangular foam target locations and an obstacle on the walking surface. The main outcome measures were foot placement distance error, intra-class correlation coefficients (ICC), and the smallest detectable difference (SDD).ResultsMean absolute values of the foot placement distance errors were 14.0 ± 4.5 mm for medio-lateral deviation and 27.2 ± 2.1 mm for anterior–posterior deviation, respectively. ICC values for test–retest reliability showed ‘fair to good’ to ‘excellent’ reliability across all conditions with values ranging from 0.63 to 0.94. SDD values were between 3.6 and 37.3 mm.ConclusionThe protocol showed good reliability for test–retest measurements of foot placement accuracy, thus making this protocol a reliable and location-independent tool to assess performance of foot placement in elderly in assisted-living settings. In the future, measurements with elderly fallers and non-fallers should be conducted to assess validity of the protocol.     

Mechanical energy profiles of the combined ankle–foot system in normal gait: Insights for prosthetic designs

Over the last half-century, the field of prosthetic engineering has continuously evolved with much attention being dedicated to restoring the mechanical energy properties of ankle joint musculatures during gait. However, the contributions of ‘distal foot structures’ (e.g., foot muscles, plantar soft tissue) have been overlooked. Therefore, the purpose of this study was to quantify the total mechanical energy profiles (e.g., power, work, and work-ratio) of the natural ankle–foot system (NAFS) by combining the contributions of the ankle joint and all distal foot structures during stance in level-ground steady state walking across various speeds (0.4, 0.6, 0.8 and 1.0 statures/s). The results from eleven healthy subjects walking barefoot indicated ankle joint and distal foot structures generally performed opposing roles: the ankle joint performed net positive work that systematically increased its energy generation with faster walking speeds, while the distal foot performed net negative work that systematically increased its energy absorption with faster walking speeds. Accounting for these simultaneous effects, the combined ankle–foot system exhibited increased work-ratios with faster walking. Most notably, the work-ratio was not significantly greater than 1.0 during the normal walking speed of 0.8 statures/s. Therefore, a prosthetic design that strategically exploits passive-dynamic properties (e.g., elastic energy storage and return) has the potential to replicate the mechanical energy profiles of the NAFS during level-ground steady-state walking.     

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

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

Can bone marrow edema be seen on STIR images of the ankle and foot after 1 week of running?

PURPOSE: To evaluate whether initiation of running in sedentary individuals would lead to bone marrow edema on MR images, within the time span of 1 week. MATERIALS AND METHODS: The feet of 10 healthy volunteers were imaged by MR imaging before and after running during 30 min a day for 1 week. The images were evaluated by consensus of 2 musculoskeletal radiologists who graded the presence of bone marrow edema on a 4-point scale. Edema scores and number of bones involved before and after running were compared statistically. RESULTS: Edema was present on the baseline images in 3 subjects. After running edema showed an increase or was present in 5 subjects. The changes after running were statistically significant. Bones involved were the talus, calcaneus, navicular bone, cuboid bone, and 5th metatarsal. CONCLUSION: Edema patterns can be seen in the feet of asymptomatic individuals. During initiation of running an increase of edema or development of new edema areas can be seen.     

Do ankle foot orthoses modify postural control during bipedal quiet standing following a localized fatigue of the ankle muscles?

The purpose of the present experiment was to investigate the effects of wearing ankle foot orthoses (AFO) on postural control during bipedal quiet standing following a localized fatigue of the ankle muscles. To this aim, eight young healthy subjects were asked to stand upright as immobile as possible with and without AFO in two conditions of non-fatigue and fatigue of the ankle muscles. The center of foot pressure displacements (CoP) were recorded using a force platform. Larger CoP displacements in the fatigue than non-fatigue condition were observed without AFO along both the medio-lateral and antero-posterior axes. Interestingly, with AFO, these destabilizing effects were not observed along the medio-lateral axis. Altogether, the present findings suggested that the AFO allowed the subjects to limit the postural perturbation induced by a localized fatigue of the ankle muscles during bipedal quiet standing.     

Do somatosensory conditions from the foot and ankle affect postural responses to plantar-flexor muscles fatigue during bipedal quiet stance?

The present study investigated the effects of somatosensory conditions at the foot and ankle on postural responses to plantar-flexor muscle fatigue during bipedal quiet stance. Twenty-two young healthy adults were asked to stand upright as still as possible with their eyes closed in three somatosensory conditions (normal, altered and improved) both prior to and after exercises inducing plantar-flexor muscle fatigue. In the normal condition, the postural task was executed on a firm support surface constituted by the force platform. In the altered condition, a 2-cm thick foam support surface was placed under the subjects' feet. In the improved condition, increased cutaneous feedback at the foot and ankle was provided by strips of athletic tape applied across both their ankle joints. Muscle fatigue was induced in the plantar-flexor muscles of both legs through the execution of a repeated standing heel raise exercise. Centre of foot pressure displacements were recorded using a force platform. Results showed that plantar-flexor muscle fatigue yielded increased centre of foot pressure displacements under normal foot and ankle sensory conditions. Furthermore, this effect was exacerbated under altered foot and ankle sensory conditions and mitigated under improved foot and ankle sensory conditions. Altogether, the present findings suggested an increased reliance on somatosensory information from the foot and ankle for controlling upright posture in the presence of plantar-flexor muscle fatigue.     

MRI and associated clinical characteristics of EV71-induced brainstem encephalitis in children with hand–foot–mouth disease

Introduction

This study was conducted to investigate MRI and associated clinical characteristics of brainstem encephalitis induced by enterovirus 71 (EV71) in children with hand–foot–mouth disease (HFMD).

Methods

We analyzed clinical and imaging data from 42 HFMD cases with EV71-induced brainstem encephalitis. All patients underwent plain and enhanced MRI cranial scans and were placed into one of two groups according to MRI enhancement results, an enhanced group or a nonenhanced group.

Results

Thirty-two cases were positive on MRI exam. The primary location of the lesion for brainstem encephalitis was the dorsal pons and medulla oblongata (32 cases), followed by the cerebellar dentate nucleus (8 cases), midbrain (5 cases), and thalamus (2 cases). Plain T1-weighted images showed isointense or hypointense signals, and T2-weighted images showed isointense and hyperintense signals. Enhanced MRI scans showed that 12 cases had slight to moderate enhancement; 4 of these were normal on plain scan. The time from MRI examination to disease onset was statistically different between the enhanced (n?=?12) and nonenhanced (n?=?21) groups with a mean of 7.67?days (SD?=?1.07) vs 11.95?days (SD?=?5.33), respectively. The most common neurological symptoms for brainstem encephalitis were myoclonus and tremor. The greater the area of affected brain, the more severe the clinical symptoms were.

Conclusion

The locations of EV71-induced HFMD-associated brainstem encephalitis lesions are relatively specific. Enhanced MRI scans could also identify the lesions missed by early plain scans. MRI scans can provide important information for clinical evaluation and treatment.