Maximum Dorsiflexion Research Articles

Acute Effects of Static and Proprioceptive Neuromuscular Facilitation Stretching of the Plantar Flexors on Ankle Range of Motion and Muscle-Tendon Behavior in Children with Spastic Cerebral Palsy-A Randomized Clinical Trial.

Stretching is considered a clinically effective way to prevent muscle contracture development in children with spastic cerebral palsy (CP). Therefore, in this study, we assessed the effects of a single session of proprioceptive neuromuscular facilitation (PNF) or static stretching (SS) on ankle joint range of motion (RoM) and gastrocnemius muscle-tendon behavior in children with CP. During the SS (n = 8), the ankle joint was held in maximum dorsiflexion (30 s). During the PNF stretching (n = 10), an isometric contraction (3–5 s) was performed, followed by stretching (~25 s). Ten stretches were applied in total. We collected data via dynamometry, 3D motion capture, 2D ultrasound, and electromyography, before and after the stretching sessions. A mixed ANOVA was used for the statistical analysis. Both ankle RoM and maximum dorsiflexion increased over time (F(1,16) = 7.261, p < 0.05, η² = 0.312; and F(1,16) = 4.900, p < 0.05, η² = 0.234, respectively), without any difference between groups. An interaction effect (F(1,12) = 4.768, p = 0.05, η² = 0.284) was observed for muscle-tendon unit elongation (PNF: −8.8%; SS: +14.6%). These findings suggest a positive acute effect of stretching on ankle function. However, SS acutely increased muscle-tendon unit elongation, while this decreased after PNF stretching, indicating different effects on the spastic muscles. Whether PNF stretching has the potential to cause positive alterations in individuals with CP should be elucidated in future studies.

Effects and Adaptation of Visual-Motor Illusion Using Different Visual Stimuli on Improving Ankle Joint Paralysis of Stroke Survivors-A Randomized Crossover Controlled Trial.

Visual-motor illusion (VMI) is an intervention to induce kinesthetic sensation from visual stimuli. We aimed to compare the effects of VMI of different visual stimuli on the paralyzed side ankle joint of stroke hemiplegic patients (hemiplegic patients) and to clarify their indication. We applied two types of VMI images of ankle dorsiflexion: ankle dorsiflexion without resistance (standard VMI (S-VMI)) and maximum effort dorsiflexion with resistance (power VMI (P-VMI)). Twenty-two hemiplegic patients were divided into two groups: Group A, which received S-VMI first and P-VMI one week later (n = 11), and Group B, which received P-VMI first and S-VMI one week later (n = 11). Immediate effects were evaluated. Outcomes were the dorsiflexion angle and angular velocity, degree of sense of agency (SoA), and sense of ownership. Patient’s characteristics of cognitive flexibility were assessed using the Trail making test-B (TMT-B). Fugl-Meyer assessment and the Composite-Spasticity-Scale were also assessed. P-VMI was significantly higher than S-VMI in SoA and dorsiflexion angular velocity. Additionally, the degree of improvement in dorsiflexion function with P-VMI was related to TMT-B and degree of muscle tone. Therefore, P-VMI improves ankle function in hemiplegic patients more than S-VMI but should be performed with cognitive flexibility and degree of muscle tone in mind.

Influence of sagittal pelvic attitude on gait pattern in normally developed people and interactions with neurological pathologies: A pilot study.

BackgroundGait Analysis of healthy people, imitating pathological conditions while walking, has increased our understanding of biomechanical factors. The influence of the pelvis as a biomechanical constraint during gait is not specifically studied. How could mimicking a pelvic attitude influence the dynamic mechanical interaction of the body segments? We proposed an investigation of the pelvic attitude role on the gait pattern of typically developed people when they mimicked pelvic anteversion and posteroversion.Materials and methodsSeventeen healthy volunteers were enrolled in this study (mean age 24.4 ± 5.5). They simulated a pelvic anteversion and posteroversion during walking, exaggerating these postures as much as possible. 3D gait analysis was conducted using an optoelectronic system with eight cameras (Vicon MX, Oxford, United Kingdom) and two force plates (AMTI, Or-6, Watertown, MA, United States). The kinematic, kinetic, and spatio-temporal parameters were compared between the three walking conditions (anteversion, posteroversion, and normal gait).ResultsIn Pelvic Anteversion gait (PA) we found: increased hip flexion (p < 0.0001), increased knee flexion during stance (p = 0.02), and reduction of ankle flexion-extension Range of Motion (RoM) compared with Pelvic Normal gait (PN). In Pelvic Posteroversion gait (PP) compared with PN, we found: decreased hip flexion-extension RoM (p < 0.01) with a tendency to hip extension, decreased knee maximum extension in stance (p = 0.033), and increased ankle maximum dorsiflexion in stance (p = 0.002).ConclusionThe configuration of PA contains gait similarities and differences when compared with pathologic gait where there is an anteversion as seen in children with Cerebral Palsy (CP) or Duchenne Muscular Dystrophy (DMD). Similarly, attitudes of PP have been described in patients with Charcot-Marie-Tooth Syndrome (CMT) or patients who have undergone Pelvic Osteotomy (PO). Understanding the dynamic biomechanical constraints is essential to the assessment of pathological behavior. The central nervous system adapts motor behavior in interaction with body constraints and available resources.

Inertia Sensors for Measuring Spasticity of the Ankle Plantarflexors Using the Modified Tardieu Scale-A Proof of Concept Study.

Ankle spasticity is clinically assessed using goniometry to measure the angle of muscle reaction during the Modified Tardieu Scale (MTS). The precision of the goniometric method is questionable as the measured angle may not represent when the spastic muscle reaction occurred. This work proposes a method to accurately determine the angle of muscle reaction during the MTS assessment by measuring the maximum angular velocity and the corresponding ankle joint angle, using two affordable inertial sensors. Initially we identified the association between muscle onset and peak joint angular velocity using surface electromyography and an inertial sensor. The maximum foot angular velocity occurred 0.049 and 0.032 s following the spastic muscle reaction for Gastrocnemius and Soleus, respectively. Next, we explored the use of two affordable inertial sensors to identify the angle of muscle reaction using the peak ankle angular velocity. The angle of muscle reaction and the maximum dorsiflexion angle were significantly different for both Gastrocnemius and Soleus MTS tests (p = 0.028 and p = 0.009, respectively), indicating that the system is able to accurately detect a spastic muscle response before the end of the movement. This work successfully demonstrates how wearable technology can be used in a clinical setting to identify the onset of muscle spasticity and proposes a more accurate method that clinicians can use to measure the angle of muscle reaction during the MTS assessment. Furthermore, the proposed method may provide an opportunity to monitor the degree of spasticity where the direct help of experienced therapists is inaccessible, e.g., in rural or remote areas.

Effects of flat-flexible shoes on lower limb joint kinetics and kinematics in gait

Flat-flexible shoes with unique characteristics, such as low pitch and flexibility, can increase the efficiency of ankle energy and running performance. If flat-flexible shoes have the same effect during walking, they could be used for gait training. This study aimed to investigate the effects of flat-flexible shoes on the kinematics and kinetics of the lower limb. Twenty-one healthy young adults (21.8 ± 4.6 years) participated in this study. The participants wore flat-flexible and standard athletic shoes with reflective markers attached according to the Plug-in-Gait model. Walking motion was recorded using infrared cameras and a treadmill embedded with force plates. The angle(s), moment(s), and power(s) of the ankle, knee, and hip joints were calculated. Paired t-test and Wilcoxon’s signed-rank test were used to compare the parameters between the two footwear types. The use of flat-flexible shoes increased maximum ankle dorsiflexion and knee flexion angles. The maximum ankle plantar flexion angle was significantly reduced. There was no significant difference in the joint moment between the two footwear types. The peaks of ankle power absorption in late stance, ankle power generation, and hip power generation significantly increased with the use of flat-flexible shoes. These results suggest that flat-flexible shoes have potential as a tool to promote ankle energy storage and release during gait.

Changes in tibial nerve stiffness during ankle dorsiflexion according to in-vivo analysis with shear wave elastography.

A more detailed assessment of pathological changes in the tibial nerve (TN) is needed to better assess how physical therapy influences TN pathologies. The cross-sectional nerve area can be used for TN assessment but may be influenced by individual differences in parameters, such as body height, body weight, and foot length. Therefore, there are no known reliable noninvasive quantitative methods for assessing TN neuropathy. Although recent ultrasonographic studies reported that TN stiffness changes could be used to assess TN neuropathies of the foot, these studies did not consider the joint position, and peripheral nerve tension can change with joint movement. Therefore, we considered that TN stiffness assessment could be improved by analyzing the relationship between ankle joint position and TN stiffness. This study aimed to investigate the relationship between TN stiffness and ankle angle changes using shear wave elastography. We hypothesized that the TN shear wave velocity significantly increases with ankle dorsiflexion and that the total ankle range or maximum dorsiflexion range correlates with the shear wave velocity.This cross-sectional study included 20 TNs of 20 healthy adults. Ultrasonography and shear wave elastography were used to evaluate the TN. TN stiffness was measured at 5 ankle positions as follows: maximum dorsiflexion (100% df), plantar flexion in the resting position (0% df), and 3 intermediate points (25% df, 50% df, and 75% df).TN shear wave velocity increased with an increase in ankle df angle. While total ankle range was significantly and negatively correlated with TN stiffness in all ankle positions, the maximum ankle df angle was significantly and negatively correlated only at 75% and 100% df.TN stiffness below 50% df may be affected by gliding or decreased nerve loosening, and TN stiffness above 75% df may be influenced by nerve tensioning. When measuring TN stiffness for diagnostic purposes, TN should be assessed at an ankle joint angle below 50% df.

Defining Equinus Foot in Cerebral Palsy.

Background: Equinus foot is the deformity most frequently observed in patients with cerebral palsy (CP). While there is widespread agreement on the treatment of equinus foot, a clear clinical definition has been lacking. Therefore, we conducted this study to evaluate functional changes in gait analysis in relation to maximum possible dorsiflexion (0°, 5°, 10° and 15°) and in two subgroups of CP patients (unilateral and bilateral). Methods: In this retrospective study, CP patients with different degrees of clinically measured maximum dorsiflexion were included. We further subdivided patients into unilaterally and bilaterally affected individuals and also included a healthy control group. All participants underwent a 3D gait analysis. Our goal was to determine the degree of maximum clinical dorsiflexion where the functional changes in range of motion (ROM) and ankle moment and power during gait were most evident. Then, a subgroup analysis was performed according to the affected side. Results: In all, 71 and 84 limbs were analyzed in unilaterally and bilaterally affected subgroups. The clinically 0° dorsiflexion group barely reached a plantigrade position in the 3D gait analysis. Differences in ROM were observed between subgroups. Ankle moment was quite similar between different subgroups but to a lower extent in the unilateral group. All CP patients had reduced ankle power compared to controls. Conclusions: A cutoff value of clinical ≤ 5° dorsiflexion is the recommended value for defining a functionally relevant equinus foot in CP patients.

Rabbit hindlimb kinematics and ground contact kinetics during the stance phase of gait.

Though the rabbit is a common animal model in musculoskeletal research, there are very limited data reported on healthy rabbit biomechanics. Our objective was to quantify the normative hindlimb biomechanics (kinematics and kinetics) of six New Zealand White rabbits (three male, three female) during the stance phase of gait. We measured biomechanics by synchronously recording sagittal plane motion and ground contact pressure using a video camera and pressure-sensitive mat, respectively. Both foot angle (i.e., angle between foot and ground) and ankle angle curves were unimodal. The maximum ankle dorsiflexion angle was 66.4 ± 13.4° (mean ± standard deviation across rabbits) and occurred at 38% stance, while the maximum ankle plantarflexion angle was 137.2 ± 4.8° at toe-off (neutral ankle angle = 90 degrees). Minimum and maximum foot angles were 17.2 ± 6.3° at 10% stance and 123.3 ± 3.6° at toe-off, respectively. The maximum peak plantar pressure and plantar contact area were 21.7 ± 4.6% BW/cm2 and 7.4 ± 0.8 cm2 respectively. The maximum net vertical ground reaction force and vertical impulse, averaged across rabbits, were 44.0 ± 10.6% BW and 10.9 ± 3.7% BW∙s, respectively. Stance duration (0.40 ± 0.15 s) was statistically significantly correlated (p < 0.05) with vertical impulse (Spearman’s ρ = 0.76), minimum foot angle (ρ = −0.58), plantar contact length (ρ = 0.52), maximum foot angle (ρ = 0.41), and minimum foot angle (ρ = −0.30). Our study confirmed that rabbits exhibit a digitigrade gait pattern during locomotion. Future studies can reference our data to quantify the extent to which clinical interventions affect rabbit biomechanics.

Relationship between Step-by-Step Foot Kinematics and Sprint Performance.

Foot stiffness is a modulator of sprint performance. However, studies that analysed foot angular velocities using inertial measuring units (IMU) for different events within the sprint contact time phase are scarce. The aim of this study was to investigate the relationship between angular foot step-by-step kinematics and sprint performance during a 50-metre sprint in experienced male and female sprinters. Foot kinematics were measured using IMU devices integrated with a 3-axis gyroscope and a laser gun. The main findings were that men performed faster sprints (6.11 ± 0.35 s vs. 6.77 ± 0.24 s), but the maximal angular foot kinematics were the same between sexes. Maximal angular velocities increased until strides 6–7, where they stabilized. Time from touchdown to maximal dorsiflexion velocity did not change between strides, whereas time from maximal dorsiflexion velocity to toe off decreased until stride 6. Plantarflexion velocities, especially in toe off, showed the greatest associations with sprint times, whereas maximal dorsiflexion velocity presented no association with sprint times. The time from dorsiflexion velocity to toe off from stride 7 onwards determined the sprint performance and was shorter for faster sprinters. The analysis of these variables provides essential information to athletes and coaches that may help to enhance the quality and efficiency of the sprint cycle by giving detailed information on each single stride of the sprint.

The effect of two types of ankle orthoses on the repetitive rebound jump performance

BackgroundAnkle orthotics decreases the maximal vertical jump height. It is essential to maximize jump height and minimize ground contact time during athletic performance. However, the effect of ankle orthotics on athletic performance has not been reported. We aimed to investigate the effect of ankle orthotics on squat jump (SJ), countermovement jump (CMJ), and repetitive rebound jump (RJ) performance.MethodsTwenty healthy volunteers performed SJ, CMJ, repetitive RJ under no-orthosis and two orthotic conditions (orthosis 1 and orthosis 2). During SJ and CMJ, we measured the vertical ground reaction force and calculated the following parameters: jump height, peak vertical ground reaction force, rate of force development, net vertical impulse, and peak power. During repetitive RJ, the jump height, contact time, and RJ index were measured. A two-dimensional motion analysis was used to quantify the ankle range of motion in the sagittal plane during SJ, CMJ, and repetitive RJ.ResultsMultivariate analysis of variance and the post hoc test showed orthosis 2 significantly decreased in the vertical jump height (p = 0.003), peak power (p = 0.007), and maximum plantarflexion and dorsiflexion angles (p < 0.001) during SJ Ankle orthoses 1 and 2 did not influence to the RJ performance compared to those using the no-orthosis condition. Additionally, orthosis 2 significantly decreased the jump height at the end of repetitive RJ (p = 0.046).ConclusionsThese results suggest that ankle orthosis do not affect average RJ performance but should be considered when performing repetitive jumps frequently.

Replicating and redesigning ankle-foot orthoses with 3D printing for children with Charcot-Marie-Tooth disease

BackgroundChildren with the most common inherited neuropathy, Charcot-Marie-Tooth disease (CMT), are often prescribed ankle-foot orthoses (AFOs) to improve walking ability and prevent falls by reducing foot drop, postural instability, and other gait impairments. These externally worn assistive devices are traditionally custom-made using thermoplastic vacuum forming. This labour-intensive manufacturing process often results in AFOs which are cumbersome due to limited design options, and are associated with low acceptability, discomfort, and suboptimal impact on gait. The aim of this study was to determine how 3D printing can be used to replicate and redesign AFOs in children with CMT. MethodsTraditional AFOs, 3D printed replica AFOs (same design as traditional AFOs), 3D printed redesigned AFOs and a shoes only control condition were compared in 12 children with CMT. 3D printed AFOs were manufactured using material extrusion in Nylon-12. 3D gait analysis (temporal-spatial, kinematic, kinetic), in-shoe pedobarography and self-reported satisfaction were used to compare conditions. The primary kinematic and kinetic outcome measures were maximum ankle dorsiflexion in swing and maximum ankle dorsiflexor moment in loading response, to capture foot drop and an absent of heel rocker. ResultsThe 3D printed replica AFOs were comparable to traditional AFOs for all outcomes. The 3D printed replica AFOs improved foot position at initial contact and during loading response and significantly reduced pressure beneath the whole foot, rearfoot and forefoot compared to the shoes only. The 3D printed redesigned AFOs produced a device that was significantly lighter (mean −35.2, SD 13.3%), and normalised maximum ankle dorsiflexor moment in loading response compared to shoes only and traditional AFOs. Significance3D printing can be used to replicate traditional handmade AFOs and to redesign AFOs to produce a lighter device with improved biomechanics by incorporating novel design features.

The changes of the calf-vein deformation and femoral vein peak velocity during ankle pump exercise with or without graduated compression stockings

ObjectivesTo analyze the changes of lower limb hemodynamics parameters before and after wearing graduated compression stockings (GCS) during ankle pump exercise in patients preparing for arthroplastic surgery.MethodThe leg veins of 16 patients awaiting arthroplasty were analyzed using a Sonosite M-Turbo ultrasound system during ankle pump exercise with or without GCS. The age of them was 70 ± 7 years (mean ± SD) (range 56—82 years) and body mass index was 25.8 ± 3.0 kg/m2 (range 18.0—30.5 kg/m2). Measured data including the cross-sectional area (CSA), anteroposterior (AP) diameter and lateromedial (LM) diameter of the soleus vein (SV), posterior tibial vein (PTV) and great saphenous vein (GSV). Additionally, the peak velocities of femoral vein (FV) were also measured.ResultsGCS could significantly decrease the cross-sectional area of SV, PTV and GSV in supine position at rest and maximum ankle plantar flexion. But the compression effect of GCS to SV and GSV was not observed during maximum ankle dorsiflexion. It was found that GCS application reduced the peak flow velocity of the femoral vein from 61.85 cm/s (95% CI = 50.94–72.75 cm/s) to 38.01 cm/s (95% CI = 28.42–47.59 cm/s) (P < 0.001) during ankle plantar flexion and decreased the femoral vein in these patients from 80.65 cm/s (95% CI = 70.37–90.92 cm/s) to 51.15 cm/s (95% CI = 42.58–59.73 cm/s) (P < 0.001) during ankle dorsiflexion. But this effect was not significant in supine position at rest.ConclusionsGCS could significantly reduce the peak flow velocity of the femoral vein during ankle pump exercise in the patients preparing for arthroplastic surgery.

Intra-articular pressure measurement of the first metatarsophalangeal joint of the foot

Objective: To measure the metatarsophalangeal (MTP) intra-articular pressure of the first ray before surgical intervention for hallux valgus (HV), recurrent HV, and hallux rigidus (HR). Methods: This is a cross-sectional study including a consecutive sample of patients obtained from 1/1/2009 and 8/30/2015 in a center in Argentina. Measurements were made with a Stryker® pressure gauge, and results were expressed in mmHg. Descriptive and comparative statistics (Mann-Whitney test) were performed. Results: A total of 166 feet were included, 120 cases with HV, 20 with HR, and 26 with recurrent HV; the sample consisted of men and women aged 15 to 90 years. The greater HV deformity, the higher intra-articular pressure at rest and during maximal dorsiflexion and maximal plantar flexion. Conversely, an inverse situation is observed in HR: the greater the deformity, the lower intra-articular pressure. Median resting intra-articular pressure of the first MTP joint of the foot was 3 mmHg in mild HV, compared to 23 mmHg in early-stage HR (p=0.001). Conclusions: The measurement of intra-articular pressure could be a useful tool to differentiate early stages of joint diseases of the first ray of the foot. Level of Evidence II; Prognostic Studies; Retrospective Study.

Biomechanical Analysis of the Influence of SACH Foot and Dynamic-Response Foot in Individual With Unilateral Transtibial Amputee During Running

Objective: Amputation of the lower limb due to loss of part of the musculoskeletal structure reduces performance and increases injury during locomotion. The effect of various types of prosthetic feet has been analyzed in several studies during running. The purpose of this study was a biomechanical analysis of the influence of SACH and Dynamic-Response foot on several kinetic variables in the stance phase of running in individuals with unilateral transtibial amputation. Materials &amp; Methods: In this semi-experimental study, 8 left foot transtibial amputees were included in this study using an available or easy sampling method. The target population was unilateral transtibial amputees who were able to run and the available population included left transtibial amputees who were referred to Kosar Rehabilitation Center in Tehran from 2008 to 2012. To adapt to the foot, each foot was used by the subjects for at least one week before the experiment. All subjects participated in 3 running evaluation sessions; 1 session involving the use of their own foot (familiarization session), 1 session involving the use of SACH foot, and 1 session involving the use of Dynamic foot. Only data from the 2 last sessions were used to compare both feet. Each subject runs in 12-meter walkway 3 times at a speed of 2.5 meters per second. The same running speed was chosen for the comparability of kinetic variables. Sport shoes were used to bring the test conditions closer to the actual running conditions. In each session, 3 successful trials were performed so that the foot was in full and perfect contact with the force plate. Kistler force plate and three-dimensional motion analysis Vicon system were used to collect kinetic and kinematic data, respectively. The motion and the force plate data were sampled simultaneously at 200 and 1000 Hz, respectively. The trajectories of the markers and analog data were filtered using the predicted mean square error adaptive filter in version 1.7 of the Vicon software package. The Kinetic variables were generated using the dynamic model of the Vicon Plug-in-Gait. The vertical ground reaction force was normalized for body weight. In the present study, 5 variables were selected for biomechanical analysis of feet. The maximum vertical ground reaction force, power, spring efficiency, ankle moments at the amputated leg, and the symmetry ratio (percentage) of the maximum vertical ground reaction force between the amputated leg and the intact leg were calculated. All values ​​in each trial were averaged for each subject with each foot. A paired t-test and a Wilcoxon test were used to analyze the data based on normality (P ≤0.05). Results: In examining the normality of the data distribution, the results showed that the data of maximum power absorption of the ankle with the SACH foot and the maximum power absorption of the hip with the Dynamic-Response foot did not have a normal distribution and other variables had a normal distribution. The results of paired t-test and Wilcoxon showed that Spring Efficiency and Maximum Plantar Flexion were significantly different between the SACH and Dynamic-Response feet (P ≤0.05). The Spring Efficiency was greater with Dynamic-Response foot than the SACH foot (P =0.05), although the Maximum Plantar Flexion with the SACH foot was greater than Dynamic-Response foot (P =0.05). While there is no statistical difference between the maximum vertical ground reaction force, maximum power absorption and generation in the ankle, maximum power absorption and generation in the knee, maximum power absorption and generation in the hip, maximum dorsiflexion moment, and the symmetry ratio (percentage) of the maximum vertical ground reaction force between the amputated leg and the intact leg. Conclusion: The results of the study showed that the spring efficiency with Dynamic-Response foot was greater than SACH foot and closing to the spring efficiency of a normal foot. With this perspective, the Dynamic-Response foot has more natural performance than the SACH foot.

Intraoperative checking of the first ray rotation and sesamoid position through sonographic assistance

IntroductionHallux valgus (HV) deformity affects the orientation of the metatarsophalangeal (MTP) joint in three planes. Displacement in the coronal plane results in axial rotation of the first metatarsal, with progressive subluxation of the first MTP joint. Multiple techniques have been described to correct the malrotation itself. However, none of them have checked intraoperatively the final position of the first metatarsal head and sesamoids previous to the fixation of the Lapidus procedure or first metatarsal bone osteotomies. The aim of this article is to describe a novel technique to check the first ray rotation and sesamoids position through sonographic assistance.Materials and methodsBefore fixation of the Lapidus procedure, with the ankle in maximal dorsiflexion, the surgeon takes the linear ultrasound probe and places it on the sole to visualize the sesamoids, which should be viewed at the same level, with the flexor hallucis longus (FHL) centered between both. Once the ideal position of the head of the first ray has been achieved, temporary fixation with K-wires is performed over the first TMT joint and M1–M2 joint for further sonographic verification of the sesamoids beneath the first metatarsal head. The height of the sesamoids relative to the second metatarsal head should be checked by sonographic control too.ResultsFour patients were included. Three females and one male. Their mean age was 76.4 years (R 61–72). Their mean BMI was 29 (R 27.5–32.24). The mean IMA (intermetatarsal angle) was 18.2 (R 17.2–19) degrees and the mean MPA (metatarsophalangeal angle) was 50 (R 36–63) degrees.ConclusionsSonographic assistance, is a widely available, inexpensive, and comparative imaging technique that can guide the first ray rotation and sesamoids position in HV surgery, theoretically improving radiological outcomes.

Position of the first metatarsophalangeal joint and the effect on hallux abductovalgus deformity progression and reversal

There has not been any literature describing changes in intermetatarsal (IM) angle 1,2 of the foot related to position of the first metatarsophalangeal joint (MTPJ). This study looks at the effect on the IM angle with loading of the foot and attempted dorsiflexion of the 1st MTPJ in 14 consecutive feet with bunion deformity. We also examine the effect of maximal dorsiflexion of the first MTPJ on the IM angle 1,2. This is a radiographic study. The pathogenesis of hallux abductovalgus is a subject of much discussion. Conclusive evidence has not been obtained as to the etiology of this common condition, and many theories have been advanced. This study shows that there is an effect on the IM angle under different angular conditions of the first MTPJ. The author concludes that there is a significant decrease in the IM angle between mets 1,2 with dorsiflexion of the first MTPJ and a change of the deformity with dorsiflexion attempted with weight bearing (WB) in all subjects. It is suggested that restoration of motion of the first MTPJ decreases the deformity. This leads the author to believe that conservative care and restoration of motion of the first MTPJ may reduce the deformity of hallux abductovalgus as assessed by IM angle 1,2.

Correcting for heel lift reduces ankle joint operating range for the ankle plantar flexor strength curve

The ankle plantar flexor muscles are stronger in ankle dorsiflexion than plantar flexion. However, heel lift is commonly observed during ankle plantar flexor strength testing, a phenomenon that would alter ankle angle. The effect of heel lift on the relation between ankle angle and plantar flexor strength has largely been ignored. This research examined the ankle plantar flexor strength curve, correcting for ankle plantar flexion due to heel lift. Six males and six females performed maximal isometric ankle plantar flexor contractions at five ankle positions. The purpose-built dynamometer could measure both resting ankle angle and foot plantar flexion due to heel lift; the combination was used to calculate the ankle angle during contraction. A significant interaction between dynamometer position and heel lift correction was observed (P < 0.001). The interaction had a linear trend (adjusted R2 = 0.94, P < 0.001) indicating heel lift was smallest in ankle plantar flexion and increased with greater ankle dorsiflexion. The difference in ankle angle following heel lift correction occurred with the ankle in dorsiflexion (P < 0.001, Cohen’s d = 2.6) and near neutral (P < 0.001, Cohen’s d = 2.2). After correcting for heel lift, the ankle plantar flexor strength curve was compressed to a smaller range of ankle angles, specifically, reducing the maximum dorsiflexion angle.

Simulated Performance of an Energy Storage and Return Prosthetic Ankle Based on Cams and Miniature Hydraulics

Prosthetic feet are limited in their ability to mimic the energy-recycling behavior of an intact ankle, negatively affecting lower-limb amputees’ gait in terms of metabolic cost and walking speed. To overcome these weaknesses, a novel prosthetic ankle based on hydraulics is described here. The ankle joint drives two cams, which in turn drive two hydraulic rams. One cam-ram system captures the negative work done from foot-flat until maximum dorsiflexion, by pumping oil into an accumulator, while the other returns positive work during push-off providing forward propulsion through fluid flowing from the accumulator to the ram. Simulation results are promising: of the total negative work done by the prosthetic ankle over the gait cycle (i.e., the maximum amount of energy available to be stored), 78% is returned, mainly during push-off; 14% is carried forward for future gait cycles; and 8% is lost. The estimated prosthesis height and mass are approximately <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${26}.{5} {cm}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${2}.{3} {kg}$ </tex-math></inline-formula> . Nonetheless, further work is necessary to realise a prototype for bench and in-vivo testing. By mimicking intact ankle torque and efficiently storing and returning energy at the ankle joint, this new design may contribute to reducing amputees’ metabolic cost of walking.

Anterior Hemi-epiphysiodesis of the Distal Tibia for Residual Equinus Deformity in Children with Clubfeet

Background: Residual equinus deformity in toddlers with a history of clubfoot can be managed with soft tissue release, provided there is no articular incongruity. Distal tibia osteotomy is a reasonable choice in mature patients with a flattened talus provided the growth plate is closed. Anterior distal tibia hemi-epiphysiodesis is an option for children with articular incongruity who have substantial growth remaining. The aim of this study is to evaluate radiographic and clinical outcomes of this method. Methods: Fourteen clubfoot patients (20 ankles) with residual equinus deformity were treated between 2010-2015 with anterior distal tibial hemi-epiphysiodesis utilizing size appropriate modular plate and screw constructs. Patients were evaluated clinically and radiographically. Oxford Ankle Foot Questionnaire for Children (and caregivers) with supplemental questions were requested at most recent follow-up. Results: There were 12 males and 2 females, mean age 10 years at surgery (50-152 months), with the minimum 18 months of radiographic follow-up (Mean 34 months). Pre-surgical mean radiographic anterior distal tibial angle (ADTA) was 87.8 degrees (79-100) and mean maximum dorsiflexion was -5.7 degrees (-40-7). At follow-up, mean improvement of radiologic ADTA was 18 degrees and mean clinical dorsiflexion improvement was 8.4 degrees. On the Oxford Ankle Foot Questionnaire, children reported a mean functional score of 47% in the “Physical” domain, 71% in “School and Play”, 70% in “Emotional”, and 38% in footwear. Parents reported mean scores of 45% in Physical, 69% in School and Play, 56% in Emotional, and 28% in footwear. Sixty percent of parents reported increased foot flexibility, 80% noted improvement in their child’s walking, and 100% would choose this surgery again. Conclusions: Anterior distal tibial hemi-epiphysiodesis is a viable option for treatment of residual equinus in children with a clubfoot history and open growth plates. Radiographic improvement was at least 2x greater than the clinically measured improvements of dorsiflexion; yet each family would undergo the surgery again as they perceived an improvement in function.

Порівняльний аналіз валідності гоніометричного, інклінометричного та рентгенологічного методів вимірювання розгинання у гомілковостопному суглобі

Актуальність. Пошук оптимального методу оцінки амплітуди розгинання в гомілковостопному суглобі (ГС) залишається актуальним предметом наукових дискусій. Мета роботи — провести порівняльний аналіз валідності гоніометричного та інклінометричного методів вимірювання обсягу розгинання у гомілково-стопному суглобі порівняно із рентгенологічними показниками. Матеріали та методи. У дослідження ввійшло 25 здорових, фізично активних осіб (50 гомілковостопних суглобів), серед яких чоловіків було 18, жінок— 7; середній вік обстежуваних становив 25,8 ± 5,2 року; середнє значення індексу маси тіла — 25,01 ± 5,01. Обсяг розгинання у ГС вимірювали при навантаженні за допомогою двоплощинного гоніометра та інклінометра і порівнювали їх з рентгенологічними показниками. Результати вимірювань оцінювали методами описової статистики. Результати. Cередні значення розгинання у ГС, виміряні за допомогою двоплощинного гоніометра, становили 37,62 ± 5,56°; інклінометра — 40,61 ± 5,15°; рентгенологічні показники — 23,69 ± 7,25°. Різниця між середніми була вірогідною (p &lt; 0,001). Середнє значення коефіцієнта варіації для рентгенологічного методу становило 0,31 і значно переважало показники гоніометричного (0,15) та інклінометричного (0,13) методів вимірювання (p &lt; 0,001). Рентгенографія ГС при навантаженні при максимальному розгинанні стопи призводить до збільшення показників тало-1-метатарзального кута. Висновки. Значення кутових параметрів розгинання у ГС при гоніометричному та інклінометричному методах вимірювання суттєво перевищують рентгенологічні показники. Більший коефіцієнт варіації для рентгенологічного дослідження вказує на кращу відтворюваність інклінометрії та гоніометрії при оцінці розгинання у ГС. Навантажувальна рентгенограма ГС в положенні максимального розгинання демонструє збільшення тало-1-метатарзального кута порівняно із нормативними значеннями, що потрібно враховувати при інтерпретації результатів рентгенологічної оцінки розгинання у ГС.