Active Toe Research Articles

Squat and tuck jump maneuver for single-legged robot with an active toe joint using model-free deep reinforcement learning

Squat and tuck jump maneuver for single-legged robot with an active toe joint using model-free deep reinforcement learning

Disease state associated with chronic toe lesions in hellbenders may alter anti-chytrid skin defenses

Hellbenders (Cryptobranchus alleganiensis) are large, aquatic salamanders from the eastern United States. Both subspecies, eastern and Ozark hellbenders, have experienced declines resulting in federal listing of Ozark hellbenders. The globally distributed chytrid fungus, Batrachochytrium dendrobatidis (Bd) has been detected in both subspecies, and Batrachochytrium salamandrivorans (Bsal) poses a new threat if introduced into North America. Ozark hellbenders also suffer a high prevalence of toe lesions of unknown etiology, with changes in host immunocompetence hypothesized to contribute. Antimicrobial peptides (AMPs) secreted from dermal granular glands may play a role in hellbender health. We collected skin secretions from free-ranging hellbenders and enriched them for small cationic peptides used for growth inhibition assays against Bd and Bsal. Generalized linear mixed models revealed the presence of active toe lesions as the strongest and only significant predictor of decreased Bd inhibition by skin peptides. We also found skin secretions were more inhibitory of Bsal than Bd. MALDI-TOF mass spectrometry revealed candidate peptides responsible for anti-chytrid activity. Results support the hypothesis that hellbender skin secretions are important for innate immunity against chytrid pathogens, and decreased production or release of skin peptides may be linked to other sub-lethal effects of disease associated with toe lesions.

P16: PHYSICAL THERAPIES FOR DVT PROPHYLAXIS IN SURGICAL PATIENTS: A SYSTEMATIC REVIEW AND EVIDENCE QUALITY APPRAISAL

Abstract Introduction Venous thromboembolism represents a significant clinical and socioeconomic burden. Surgical patients are an inherently high-risk cohort for VTE although traditional prophylactic pharmacological therapies are contraindicated in select cohorts. Novel physical therapies such as calf exercises and electrostimulation have been proposed for such patients. The aim of this systematic review is to appraise the clinical utility of novel physical therapies used for DVT prophylaxis in surgical and trauma patients. Method A systematic review of MEDLINE, EMBASE and CINAHL using a PRISMA-compliant methodology up to July 2019 was conducted. Abstract screening and data extraction were performed in duplicate. Risk of bias and quality assessments were performed for each study using the GRADE framework. Result A total of 272 articles were identified, of which 10 met inclusion criteria. Five studies evaluated the use of calf electrostimulation, the remaining studies evaluated active toe movement, bespoke compression bandages, blood flow restriction exercises, calf massage and a portable compression device. Four randomized controlled trials demonstrated a significant reduction in radiological DVT incidence with electrostimulation, post-operative massage and pneumatic compression versus controls. All included studies had a moderate to high risk of bias. Conclusion The role of physical therapies as prophylactic measures in VTE remain equivocal. No study demonstrated a significant reduction in clinically evident DVT. The physical therapies can be beneficial in patients who also received pharmacological therapy, whilst physical therapies alone may be of no benefit. Heterogenous study design and poor methodological quality limit comparison of study findings at present. Take-home message Physical therapies as prophylactic measures in venous thromboembolism may offer benefit when combined with pharmacotherapy. When used alone, physical therapies may offer no benefit.

Pedal Musculovenous Pump Activation Effectively Counteracts Negative Impact of Knee Flexion on Human Popliteal Venous Flow.

Knee scooters are commonly used for mobility instead of other devices. However, passive popliteal venous flow impedance has been observed with knee scooter usage ostensibly as a result of deep knee flexion. This study aimed to characterize the magnitude of impact knee flexion has on popliteal venous flow in relation to the degree of knee flexion when walking boot immobilized. Furthermore, the countervailing effect of standardized pedal musculovenous pump (PMP) activation was observed. Popliteal venous diameter and flow metrics were assessed with venous ultrasonography in 24 healthy individuals. Straight leg, crutch, and knee scooter positioning while wearing a walking boot and non-weight-bearing were compared. Flow was assessed with muscles at rest and with PMP activation. Of 24 participants, 16 (67%) were female. Twelve limbs (50%) were right sided. The mean age was 21.9 (SD = 3.0) years, and the mean body mass index was 21.9 (SD 1.9) kg/m2. Observer consistencies were excellent (intraclass correlation range = 0.93 to 0.99). No significant differences in mean vessel diameter, time-averaged mean velocity, and total volume flow occurred (all P > .01). Corresponding knee flexion effect sizes were small (range = -0.04 to -0.26). A significant decrease (-24%) in active median time-averaged peak velocity occurred between upright and crutch positions (20.89 vs 15.92 cm/s; P < .001) with a medium effect size (-0.51). PMP activation increased all flow parameters (all P < .001), and effect sizes were comparatively larger (>0.6) across all knee flexion positions.Clinical Significance: Knee flexion has a small to medium impact on popliteal venous return in healthy patients. Active toe motion effectively counters the negative effects of gravity and knee flexion when the ankle is immobilized.Levels of Evidence: Therapeutic, Level IV.

Single versus double tendon transfer for foot drop due to post-traumatic common fibular nerve palsy.

To compare functional outcomes of single versus double tendon transfer for foot drop correction and toe drop prevention in posttraumatic common fibular nerve palsy. A retrospective study was conducted on data from patients with posttraumatic common fibular nerve palsy treated by tendon transfer between 2001 and 2018. In cases of single tendon transfer (STT) the tibialis posterior (TP) tendon was transferred anteriorly through the interosseous membrane to a new insertion on the lateral cuneiform. In cases of double tendon transfer (DTT), the same TP tendon transfer was combined with a transfer of the flexor digitorum longus to the extensor digitorum longus and extensor hallucis longus tendons. Functional assessment was based on the Carayon score to evaluate foot drop correction and on the Yeganeh score to evaluate toe drop prevention. A total of 27 patients were included: 13 in the STT group and 14 in the DTT group. Functional results were comparable between groups in terms of reduction of foot drop, active range of ankle motion and Carayon score. Prevention of toe drop, active toe extension and Yeganeh score were significantly greater in the DTT group, however, active toe extension of was only restored in only 8 cases in the DTT group. Double transfer of TP and FDL tendons is a reliable method to restore balanced ankle dorsiflexion and prevent toe drop. However, recovery of active toe extension was inconsistent and Carayon scores were not superior to those obtained with a single TP tendon transfer.

PO 18235 - New tomographic method for measuring metatarsal rotation in hallux valgus

Introduction: Hallux valgus is a 3-dimensional deformity involving an increased intermetatarsal I/II angle and a rotational deformity of the first metatarsal bone. Kim et al. developed a method for measuring the tibial sesamoid position relative to the coronal rotation of the first metatarsal bone in computed tomography scans under simulated weight-bearing conditions. Objective: To describe a method for the topographic assessment of the correction of tibial sesamoid and metatarsal pronation using computed tomography scans under simulated weight-bearing and active toe extension. Method: We performed computed tomography under simulated weight-bearing conditions with and without active toe dorsiflexion, observing the degree of metatarsal pronation and sesamoid subluxation. For measurement purposes, we used the classifications of Kim et al. and Smith et al. Results: We observed tomographic correction, both angular and rotational, by measuring the intermetatarsal angle and tibial sesamoid position, which were confirmed by the change in the alpha angle suggested by Kim et al. Discussion: Toe extension was described as a peroneus longus tendon activation test by Klemola et al., who used this maneuver to demonstrate clinical rotational correction of hallux valgus. We described the use of a tomographic technique that followed this principle to preoperatively observe the underlying factors that may affect the rotational correction of the deformity. Conclusion: The method has the capacity for correction in various planes involving derotation of the first metatarsal bone and the relationship between such derotation and the change in sesamoid position in relation to the coronal plane of the foot.

PO 18271 - New method for the radiographic evaluation of metatarsal rotation in hallux valgus

Introduction: Hallux valgus involves, in addition to I/II intermetatarsal angle deviation, a rotational deformity of the first metatarsal bone and its sesamoids in relation to the ground. The correction of the rotation is the objective of new and recently developed surgical techniques. Objective: To describe a radiographic method that can help predict changes resulting from metatarsal rotational correction and facilitate surgical planning. Methods: We acquired radiographs in a weight-bearing anteroposterior position in patients with flexible hallux valgus while asking the patient to actively extend the toes. We compared the weight-bearing radiographs with and without the toe extension maneuver. In addition to radiography, we performed computed tomography (CT) of the nonweight-bearing active toe extension maneuver using a support platform. To measure the changes, we used the classification of Coughlin and Smith et al. Results: We observed clinical and radiographic correction, both angular and rotational, by measuring the intermetatarsal angle and sesamoid position. The changes were confirmed by CT, which showed improvement in the intermetatarsal angle, sesamoid position and metatarsophalangeal range. Discussion: The toe extension maneuver was described as a peroneus longus tendon activation test by Klemola et al., who used it to demonstrate rotational clinical correction of hallux valgus. Here, we described a radiographic method based on this principle to observe the correction power of and factors involved in metatarsal derotation using a preoperative radiographic technique. Conclusion: The method clearly demonstrated the capacity for the correction of preoperative hallux derotation in various planes, thus helping to predict the clinical, angular and rotational outcomes of surgical treatment.

Trajectory tracking using artificial neural network for stable human-like gait with upper body motion

This paper presents a trajectory generation algorithm for robots which can walk like human with movable foot and active toe. The proposed algorithm allows smooth transition between walking phases namely, single and double support phases. A neural network approach is used for solving inverse kinematics so that the biped robot follows the ankle and hip trajectories to walk. Zero moment point (ZMP) stability is ensured by taking into account the upper body movements along with the planned motion trajectories. Here, we analyze the effect of lateral upper body motion on ZMP stability. Different types of trajectories for upper body are generated, and the one which ensured the most stable locomotion is identified.

Outcome of Achilles tendon plication and transfer of peroneus longus to Achilles tendon for correction of dynamic calcaneo-valgus deformity of the foot in post-polio residual paralysis

Objective: Tendon transfers are indicated when dynamic muscle imbalance results in a deformity that interferes with ambulation or function of the extremities. Foot and ankle are the most dependent parts of the body and are subjected to greater strain than other parts. Calcaneo-valgus deformity is one of the common deformities seen in Post-Polio Residual Paralysis. A host of operative procedures have been described in the management of this deformity. We report the results of the study conducted in our institute where Achilles tendon plication and transfer of Peroneus Longus tendon to Achilles tendon has been done for dynamic calcaneo-valgus deformity of the foot in patients of post-polio residual paralysis. Methods: This is a prospective study of 37 patients with Calcaneovalgus deformity having Post-Polio Residual Paralysis presenting to Balaji Institute of Surgery, Research and Rehabilitation for the Disabled Hospital from December 2009 to December 2012. Informed consent was taken from the parents of all the patients. Ethical committee approval was also taken. Patients with age more than 7 years, ability to walk without support and Peroneal tendon having minimum motor power of grade 4 or 5 as per MRC classification are included in our study. Patients with fixed deformity at ankle joint or subtalar joint are excluded from the study. Pre-operative evaluation included detailed motor examination of the involved lower limbs as per MRC (Medical research council) classification, evaluation of deformity in the hip and knee and range of motion at ankle. AOFAS (American Orthopaedic Foot and Ankle Society) clinical rating system was used to assess the patient pre-operatively and post-operatively. The aggregate score of the AOFAS ankle-hind foot clinical rating scale pre and post operatively were analyzed with use of chi-square analysis. The level of significance of < 0.05 was considered to be significant. The surgical procedure was done under spinal anesthesia with the patient in lateral position under pneumatic tourniquet. A longitudinal incision is made starting from the tip of lateral malleolus midway between the posterior border of lateral malleolus & Achilles tendon to about 8-10cm proximally. Skin flaps are mobilized without dissecting the subcutaneous fat. The two peroneal tendons are identified as they pass down the leg and around the back of the lateral malleolus. The peroneus longus tendon is divided as distally as possible and mobilized. Similarly the Achilles tendon is identified. Plication of the Achilles tendon is done in its middle third with nylon sutures and the peroneus longus tendon is transferred through it using Fish-Mouth (Pulvertaft) tendon suturing technique and is secured over itself proximally under tension providing the tenodesis effect. While this is done the ankle is kept in plantar flexion. The deep fascia is closed over the tendon. Pneumatic tourniquet was released, and the incision was closed in layers after hemostasis was achieved. Below knee cast is applied with the foot in plantar flexion. Movements of the toes are encouraged after recovery from anesthesia. Active toe movements were encouraged in the cast. After six weeks sutures are removed and ankle foot orthoses are provided for another six weeks. During this period supervised active exercises for strengthening the Tendoachilles (static cycling exercise) are started. Patient is reassessed after six weeks and the orthoses is discarded at this stage. Conclusion: Our experience concludes that Achilles tendon plication and transfer of peroneus longus tendon to Achilles tendon is an excellent procedure which improves the dynamic calcaneo-valgus deformity of foot in patients with post-polio residual paralysis. The advantage of the procedure being easy to do with very low complication rate and improves the quality of life in patients with post-polio residual paralysis. 37 patients with the dynamic calcaneo-valgus deformity of foot in patients with post-polio residual paralysis were analyzed with average follow up period of 12.5 months. Dynamic calcaneo-valgus deformity of the foot was corrected in 89.18% of patients. The study fared with 89 percent patients satisfied with the results. The patients showed improvement in their activity limitation, maximum walking distance, gait and stability.

Heel-strike and toe-off motions optimization for humanoid robots equipped with active toe joints

SUMMARYIn this paper, a walking pattern optimization procedure is implemented to yield the optimal heel-strike and toe-off motions for different goal functions. To this end, first, a full dynamic model of a humanoid robot equipped with active toe joints is developed. This model consists of two parts: multi-body dynamics of the robot which is obtained by Lagrange and Kane methods and power transmission dynamic model which is developed using system identification approach. Then, a gait planning routine is presented and consistent parameters are specified. Several simulations and experimental tests are carried out on SURENA III humanoid robot which is designed and fabricated at the Center of Advanced Systems and Technologies located in the University of Tehran. Afterward, a genetic algorithm optimization is adopted to compute the optimal walking patterns for five different goal functions including energy consumption, stability margin, joint velocity, joint torque and required friction coefficient. Also, several parametric analyses are performed to characterize the effects of heel-strike and toe-off angle and toe link mass and length on these five goal functions. Finally, it is concluded that walking pattern without heel-strike and toe-off motions requires less friction coefficient than the pattern with heel-strike and toe-off motions. Also, heavier toe link lowers tip-over instability and slippage occurrence possibility, but requires more energy consumption and joint torque.

Adding low-cost passive toe joints to the feet structure of SURENA III humanoid robot

SUMMARYAdding active toe joints to a humanoid robot structure has lots of difficulties such as mounting a small motor and an encoder on the robot feet. Conversely, adding passive toe joints is simple, since it only consists of a spring and a damper. Due to lots of benefits of implementing passive toe joints, mentioned in the literature, the goal of this study is to add passive toe joints to the SURENA III humanoid robot which was designed and fabricated at the Center of Advanced Systems and Technologies (CAST), University of Tehran. To this end, a simple passive toe joint is designed and fabricated, at first. Then, stiffness and damping coefficients are calculated using a vision-based measurement. Afterwards, a gait planning routine for humanoid robots equipped with passive toe joints is implemented. The tip-over stability of the gait is studied, considering the vibration of the passive toe joints in swing phases. The multi-body dynamics of the robot equipped with passive toe joints are presented using the Lagrange approach. Furthermore, system identification routine is adopted to model the dynamic behaviors of the power transmission system. By adding the calculated actuating torques for these two models, the whole dynamic model of the robot is computed. Finally, the performance of the proposed approach is evaluated by several simulations and experimental results. Results show that using passive toe joints reduces energy consumption of ankle and knee joints by 15.3% and 9.0%, respectively. Moreover, with relatively large values of stiffness coefficients, the required torque and power of the knee and hip joints during heel-off motion reduces as the ankle joint torque and power increases.

A Novel Stocking to Improve Venous Return Compared to the Class 1 Compression Stocking

Category: Basic Sciences/Biologics Introduction/Purpose: Venous thromboembolism (VTE) is a serious risk of major orthopaedic surgery, associated with significant morbidity and mortality. VTE events are annually costing the US healthcare system over $13.5 billion and causing approximately 200,000 deaths each year. In current clinical practice, the risk of VTE events are reduced with various pharmacological and mechanical thromboprophylactic measures. Class 1 compression stockings are frequently used as mechanical prophylaxis due to few associated complications. The purpose of this study was to determine if the addition of a novel device to the conventional compression stockings improved venous return. Methods: This prospective study measured ejected venous volume (EVV) of the superficial femoral vein in both legs of healthy volunteers (n=10). The novel device wraps around the heel and holds the meta-tarsophalangeal joint of the great toe flexed, encouraging active toe dorsiflexion and partial ankle dorsiflexion. EVV was obtained using duplex scanning, and measured 1) when participants were supine at rest 2) with the addition of the compression stocking and 3) with the novel device in addition to the compression stocking. Results: The use of compression stockings compared to the baseline did not demonstrate a difference in EVV (6.13±0.43 ml vs 6.02±0.32 ml, p=1.000). However, the addition of the novel device significantly increased EVV compared to the baseline (6.13±0.43 ml vs 12.16±1.20 ml, p &lt; 0.001) and more importantly compared to the compression stockings alone (6.02±0.32 ml vs 12.16±1.20 ml, p &lt; 0.001). The novel device therefore augmented the EVV, two times greater than the compression stocking used as monotherapy. Conclusion: We have demonstrated that the addition of the novel device significantly improves venous return, compared to the compression stocking used as a monotherapy. DVT outcome studies assessing efficacy of this novel device in the clinical setting are now required. Nevertheless, these preliminary results demonstrate excellent potential in the next generation of VTE prophylaxis.

The effect of active toe movement (AToM) on calf pump function and deep vein thrombosis in patients with acute foot and ankle trauma treated with cast - A prospective randomized study.

Patients with foot and ankle trauma treated with cast are advised to perform toe movements to prevent venous thromboembolism (VTE). Our aim was to determine the effect of active toe movement on asymptomatic deep vein thrombosis (DVT) and venous calf pump function. Patients aged 18-60 years with acute foot and ankle trauma requiring below knee non weight bearing cast were randomized to intervention (regular active toe movement) or control groups (n=100). Patients had bilateral lower limb venous ultrasound to assess for DVT on discharge from clinic. Patients requiring chemical thromboprophylaxis were excluded. 78 completed the study. 27% sustained asymptomatic DVT, with no statistically significant difference in calf pump function or DVT incidence between groups. All DVT's occurred in the injured lower limb. Active toe movement is not a viable strategy for thromboprophylaxis in patients with acute foot and ankle trauma treated with cast.

Triple Tendon Transfer for Correction of Foot Deformity in Common Peroneal Nerve Palsy.

Anterior transfer of posterior tibial tendon (PTT) is the most common technique to correct foot drop in patients with common peroneal nerve palsy. It does not address the loss of toe extension or "toe drop." This may affect the gait pattern, and patients may not tolerate it. Described here is a technique that addresses toe drop associated with common peroneal nerve palsy. A new technique of tendon transfer using the PTT, flexor hallucis longus (FHL) tendon, and flexor digitorum longus (FDL) tendon was performed on 15 patients (13 males and 2 females) with complete common peroneal nerve palsy from 2009 to 2013. Minimum follow-up was 12 months (range, 12-50 months). The mean age was 37 years (range, 20-52 years). Based on the evaluation criteria of Carayon et al, the postoperative results for foot drop correction were excellent in 9 (60%), good in 5 (33%), and moderate in 1 (7%), and the mean active range of motion of the ankle was 46 degrees. Postoperative extension evaluation of the toes was excellent in 7 (47%), good in 5 (33%), and moderate in 3 (20%). Releasing and transferring of FDL and FHL to the toe extensors along with the anterior transfer of the PTT neutralized the deforming forces and allowed for active toe extension while strengthening ankle dorsiflexion. Movahedi Tendon Transfer was a reliable method to achieve a balanced foot and toe dorsiflexion for complete common peroneal nerve palsy. Level IV, retrospective case series.

Effect of a 2-week trial of functional electrical stimulation on gait function and quality of life in people with multiple sclerosis.

Footdrop is a common gait deviation in people with multiple sclerosis (MS) leading to impaired gait and balance as well as decreased functional mobility. Functional electrical stimulation (FES) provides an alternative to the current standard of care for footdrop, an ankle-foot orthosis (AFO). FES stimulates the peroneal nerve and activates the dorsiflexor muscles, producing an active toe clearance and a more normal gait. This study was undertaken to determine the effects of a 2-week FES Home Assessment Program on gait speed, perceived walking ability, and quality of life (QOL) among people with MS-related footdrop. Participants completed the Timed 25-Foot Walk test (T25FW) and two self-report measures: 12-item Multiple Sclerosis Walking Scale (MSWS-12) and 29-item Multiple Sclerosis Impact Scale (MSIS-29). Measures were taken without FES before and with FES after 2 weeks of full-time FES wear. A total of 19 participants (10 female, 9 male) completed the study; mean age and duration of disease were 51.77 ± 10.16 and 9.01 ± 7.90 years, respectively. Use of FES for 2 weeks resulted in a significant decrease in time to complete the T25FW (P < .0001), the MSWS-12 standardized score (P < .0001), and the MSIS-29 total (P < .0001), Physical subscale (P < .0001), and Psychological subscale (P = .0006) scores. These results suggest that use of FES can significantly improve gait speed, decrease the impact of MS on walking ability, and improve QOL in people with MS-related footdrop even over a short period of time.

Effects of toe stiffness on ankle kinetics in a robotic transtibial prosthesis during level-ground walking

Robotic transtibial prostheses are gaining popularity, as they significantly improve amputees’ locomotion. Existing studies mainly concentrate on the importance of ankle joints in these prostheses. However, there are few studies that focus on the effects of prosthetic toe joints. Different from human feet, most prosthetic feet are single-segment structures without toe joints. In order to develop more human-like prostheses with ankle and toe joints, it is of great importance to investigate the effects of toe stiffness on ankle kinetics, as it contributes to the design and control optimizations. In this paper, we analyze the effects of toe stiffness on ankle kinetics in a robotic transtibial prosthesis we have built recently. Dynamic models of the prosthesis’ ankle and toe joints are built. The imposed plantar pressures and objective joint angles of these models are obtained from locomotion experiments on able-bodied subjects. Simulation results indicate when the toe joint is fixed, the ankle energy consumption in one gait cycle is almost 1.2 times of that when the toe joint is driven to track the able-bodied toe motion. Experiments of the prosthesis prototype are carried out on an amputee subject with a transtibial amputation. The results show that compared with the fixed toe joint either the active toe joint or the passive toe joint can reduce the ankle output moment and power consumption. This means adding a toe joint to the foot can reduce the designing requirements of the ankle joint. In addition, the active toe joint can help the prosthesis perform more human-like behaviors compared with the passive toe joint. On the other hand, the passive toe joint can simplify the prosthesis structures and reduce the total weight compared with the active toe joint.

Kinematics of a New 14 DOF Humanoid Biped Robot

This paper proposes a novel architecture for a biped robot with six DOFs per leg and an active toe DOF (Degrees of Freedom). The arrangement of three successive DOFs paralleled to each other makes its inverse kinematics simple and decoupled by omitting one DOF which is unnecessary when walking. And this work presents close equations for the forward and inverse kinematics. The results can be used in the kinematic control study of the robot.

Kinematics and Dynamics of a New 16 DOF Humanoid Biped Robot with Active Toe Joint

Humanoid biped robots are typically complex in design, having numerous Degrees-of-Freedom (DOF) due to the ambitious goal of mimicking the human gait. The paper proposes a new architecture for a biped robot with seven DOF per each leg and one DOF corresponding to the toe joint. Furthermore, this work presents close equations for the forward and inverse kinematics by dividing the walking gait into the Sagittal and Frontal planes. This paper explains the mathematical model of the dynamics equations for the legs into the Sagittal and Frontal planes by further applying the principle of Lagrangian dynamics. Finally, a control approach using a PD control law with gravity compensation was recurred in order to control the desired trajectories and finding the required torque by the joints. The paper contains several simulations and numerical examples to prove the analytical results, using SimMechanics of MATLAB toolbox and SolidWorks to verify the analytical results.

On the signals underlying conscious awareness of action

To investigate whether conscious judgments of movement onset are based solely on pre-movement signals (i.e., premotor or efference copy signals) or whether sensory feedback (i.e., reafferent) signals also play a role, participants judged the onset of finger and toe movements that were either active (i.e., self initiated) or passive (i.e., initiated by the experimenter). Conscious judgments were made by reporting the position of a rotating clock hand presented on a computer screen and were then compared to the actual measured time of movement onset. In line with previous studies, judgment errors were found to be anticipatory for both finger and toe movements. There was a significant difference between judgment errors for active and passive movements, with judgments of active movements being more anticipatory than judgments of passive movements. This is consistent with a pre-movement (from here on referred to as an “efferent”) account of action awareness because premotor and efference copy signals are only present in active movements, whereas the main source of movement information in passive movements is sensory feedback which is subject to time delays of conduction (and hence predicts later judgment times for passive movements). However, judgments of active toe movement onset time were less anticipatory than judgments of active finger movement onset time. This pattern of results is not consistent with a pure efferent account of conscious awareness of action onset – as this account predicts more anticipatory judgments for toe movements compared to finger movements. Instead, the data support the idea that conscious judgments of movement onset are based on efferent (i.e., premotor, efference copy) and reafferent (i.e., feedback from the movement) components.

Active geometry control suspension system for the enhancement of vehicle stability

The active control of suspension geometry has historically been a challenging perspective for chassis teams of worldwide automakers. Manufacturers and suppliers have offered different solutions, but few have succeeded in combining a marked improvement in handling performance, low-energy consumption, simplicity, and low cost. The new and revolutionary approach of an active geometry control suspension (AGCS) reinvents the possibilities of rear-suspension active toe control. This system employs the use of the complexity of a rear multi-link suspension, and a clever design layout to minimize the energy use. Additionally, because of an efficient control logic strategy, the vehicle-handling performance and stability are substantially improved. The system is the most successful in controlling vehicle transient situations initiated mainly by aggressive lane-change manoeuvres at medium to high speeds. This paper presents the most relevant actions of the development process of the AGCS. The use of different evaluation methods and accurate measurement equipment was crucial for optimization of the system. The methods presented combine subjective evaluations in different road conditions (icy, wet, and dry asphalt), suspension kinematics and elastokinematics characterization, and objective road measurements using dynamic wheel position measurement equipment. Finally, a comprehensive summary of the handling-test results are explained, which outline the efficiency of the system, and its influence on the active safety level of the vehicle.