Pronation Movements Research Articles

Ulnar osteotomy and the ilizarov mini-fixator for pediatric chronic monteggia fracture-dislocations.

Treatment of chronic Monteggia fracture-dislocations remains controversial in skeletally immature patients. The present study aimed to review the clinical outcomes of surgical treatment with an Ilizarov mini-fixator for chronic Monteggia fracture-dislocations in children. From April 2003 to March 2014, 5 pediatric patients (4 males, 1 female) with chronic Monteggia fracture-dislocation were treated with an Ilizarov mini-fixator at our institution. The median age at the time of surgery was 9 years (range 5–14 years), median duration from injury to surgery was 31 months (range 2–125 months), and median duration of follow-up was 12 months (range 11 months–10 years). All patients underwent opening wedge osteotomy of the proximal ulna followed by the application of an Ilizarov mini-fixator. Although closed reduction was attempted after ulnar osteotomy and application of the Ilizarov mini-fixator, open reduction of the radial head was required in all patients. In 4 patients, dense scar tissue in the radiocapitellar joint was excised to enable reduction of the radial head; the remaining patient had traumatic radioulnar synostosis, and underwent separation of the synostosis followed by anconeus interposition arthroplasty. No patient received bone grafting at the ulnar osteotomy site, repair or reconstruction of the annular ligament, or temporary fixation of the radial head with transarticular wire. The median period of external fixation was 10 weeks (range 8–13 weeks). Although there were no severe complications such as deep infection and neurovascular disturbance, asymptomatic radial head subluxation occurred in 2 patients. The patient with traumatic synostosis had residual posterior subluxation with limitation of forearm rotation, and another patient with radial head enlargement had residual anterior subluxation. The median postoperative ranges of motion in pronation, supination, extension, and flexion were 90°, 90°, 0°, and 140°, respectively. The median Kim's elbow performance score was 65 (range 50–75) preoperatively, which improved to 94 (range 80–100) at final follow-up. The outcome was rated as excellent in 4 cases, and good in 1. In pediatric chronic Monteggia fracture-dislocations, ulnar osteotomy followed by the application of an Ilizarov mini-fixator is a viable option that is less invasive than plate fixation.

Medial Post Foot Orthotic Influences Knee Valgus Angle Excursions During a Vertical Jump Task

Medial posting is a common therapeutic midsole foot orthotic that is used to control excessive pronation movement, and creating a more supinated position of the foot. Consequently, these altered biomechanics may also create more favorable movements at other joints, such as the knee. Knee valgus angle has been identified as a risk factor for lower extremity joint injury, and medial posting may reduce excessive valgus during dynamic tasks, therefore decreasing the risk of injury. PURPOSE: Investigate if medial post orthotics influence knee valgus and performance outcomes during a vertical jump. METHODS: Thirty healthy participants volunteered (18m/12f; age 24.8 ± 3.1y; height 173.94 ± 8.72cm; mass 73.7 ± 13.2kg). Six maximal vertical jump trials were recorded using electromagnetic 3D biomechanical and force plate assessment. Three trials were performed with bilateral medial posting orthotics, and three without, with the order randomized. Max vertical jump height, jump power, and total valgus range of motion (excursion) during the take-off phase were extracted for each limb and averaged across the three trials for analysis. Paired samples t-tests were performed to assess differences in outcomes between orthotic conditions. Alpha level was set a priori at P ≤ 0.05. RESULTS: There were no differences in vertical jump height between the orthotic (46.9 ± 9.0cm) and no orthotic conditions (46.1 ± 8.6cm, t = -0.58, p = 0.56). Jump power also was the same between the orthotic (1219.4 ± 520.9) and no orthotic conditions (1243.5 ± 456.5W, t = 0.35, p = 0.72). Both the left (orthotic: 15.2 ± 7.4o; no orthotic: 18.3 ± 10.5o; t = 2.46, p = 0.02) and right (orthotic: 17.9 ± 8.6o; no orthotic: 19.9 ± 12.4o; t = 1.96, p = 0.05) limbs demonstrated significantly less knee valgus excursion when using the orthotic. CONCLUSIONS: The medial post orthotic was successful at reducing knee valgus excursion angles during a maximal vertical jump, while also maintaining vertical jump performance, measured via vertical jump height and power. Although medial posting is a common orthotic to correct excessive pronation at the foot, it may also have therapeutic efficacy at knee joint injury prevention during dynamic tasks.

A study of the extensor tendons of the hand from point of view of evolution

IntroductionBoth anatomists and the surgeons need to have knowledge of anatomy of extensor muscles and their variations but the analysis of characteristics of each of these muscles can also improve our understanding of evolution of modern human beings. Methods100 upper limbs preserved in 10% formalin were dissected to study the extensor muscles on the dorsum of forearm and hand. Results28% incidence of variation was observed. Variant muscles such as extensor carpi radialis tertius (4%), extensor digitorum brevis manus (2%) and extensor medii proprius(4%) were observed. Duplication and triplication of extensor digitorum communis tendons to the 2nd, 3rd and 4th digits was noted. A 28% incidence of absence of extensor digitorum communis tendon to the little finger was observed. DiscussionPresent study attempted to explain the presence of these extra muscles on the basis of their actions. Increased supination and pronation movements have been associated with more number of muscles/tendons in the extensor carpi radialis muscle and could explain the formation of extensor carpi radialis tertius muscle observed in the present study. The need to extend wrist and throw an object in a precise direction which was the need of the primate evolving to be the human being, could explain the extra extensors seen over the wrist and digits. A very well developed extensor mechanism is needed for precise functioning of the hand. The present study attempts to link together the functioning of individual extensor muscles to the trajectory of events involved in evolution of primates.

A human–computer interface for wrist rehabilitation: a pilot study using commercial sensors to detect wrist movements

Health conditions might cause muscle weakness and immobility in some body parts; hence, physiotherapy exercises play a key role in the rehabilitation. To improve the engagement during the rehabilitation process, we therefore propose a human–computer interface (serious game) in which five wrist movements (extension, flexion, pronation, supination and neutral) are detected via two commercial sensors (Leap motion controller and Myo armband). Leap motion provides data regarding positions of user’s finger phalanges through two infrared cameras, while Myo armband facilitates electromyography signal and inertial motion of user’s arm through its electrodes and inertial measurement unit. The main aim of this study is to explore the performance of these sensors on wrist movement recognition in terms of accuracy, sensitivity and specificity. Eight healthy participants played 5 times a proposed game with each sensor in one session. Both sensors reported over 85% average recognition accuracy in the five wrist movements. Based on t test and Wilcoxon signed-rank test, early results show that there were significant differences between Leap motion controller and Myo armband recognitions in terms of average sensitivities on extension ( $$p = 0.0356$$ ), flexion ( $$p = 0.0356$$ ) and pronation ( $$p = 0.0440$$ ) movements, and average specificities on extension ( $$p = 0.0276$$ ) and pronation ( $$p = 0.0249$$ ) movements.

P 75 Movement-induced γ oscillations in the subthalamic nucleus are increased by dopamine and scaled by velocity in patients with Parkinson’s disease

Parkinson’s disease (PD) is a basal ganglia disorder that results in general slowness of movement and an effective treatment option consists in subthalamic deep brain stimulation (DBS). Postoperatively, DBS-electrodes are externalized which gives the unique opportunity of recording local field potentials (LFP). Previous studies have shown that there are disease specific oscillatory patterns at rest, most prominently an increased β synchronization (Kuhn, 2006) that correlates with clinical symptoms of PD such as rigidity and bradykinesia (Neumann, 2016). During movement, subthalamic oscillations show an increase of γ power that increases after L-Dopa intake (Androulidakis, 2007). In the motor cortex of healthy subjects (Cheyne, 2013) as well as in the internal pallidum of dystonia patients (Brucke, 2012) γ power is moreover scaled by kinematic parameters such as movement speed or force. Here we investigated whether γ oscillations in the human STN are related to scaling of movement and to what extent this modulation is influenced by dopamine and relates to symptom severity as assessed by the UPDRS-III motor score. To shed light on these questions, 16 PD patients (4 female, mean age 58.4 years ±2.8 SEM) undergoing electrode implantation in the STN for DBS were included in the study. Bipolar LFPs from 3 contact pairs were recorded while patients on their usual dopaminergic medication performed forearm pronation movements of three amplitudes (small, medium, large). 7 patients additionally performed the task after withdrawal of the dopaminergic replacement therapy, in the so called medical OFF state (>30% increase in UPDRS score). Signals were taken to the frequency domain using wavelet analysis, averaged and normalized to a pre-trial baseline period. Normalized time frequency plots were averaged across hemispheres and patients. Statistical analysis was conducted using FDR-corrected Monte Carlo permutation tests and correlations were calculated using Spearman’s Rho. Averaged Θ (2–8 Hz), β (13–30 Hz) and γ (40–90 Hz) power were compared across hemispheres, movement amplitudes and single trial velocities and correlated with the clinical symptom severity as measured by the UPDRS-ON score. We were able to reveal a neural signature of movement in the STN consisting in a synchronization in the Θ, a desynchronization in the β and a synchronization in the γ band compared to baseline. Our findings could be of special interest in the field of adaptive stimulation in order to monitor dopamine dependent subthalamic movement related activity in relation to current motor demand.

Forearm Rotation Moments are Associated with Elbow Varus Moments

Objectives:The incidence of upper extremity injury in baseball has increased over the past decade, and much of the research into the biomechanics of pitching has focused on the shoulder and elbow. However little attention has been placed on how forearm rotation and the forearm rotation moment could affect a pitcher’s risk of injury. Therefore this study sought to determine the association between forearm moments and the elbow varus moment in collegiate baseball pitchers.Methods:Collegiate level baseball pitchers that were recruited for this study were actively pitching for an NCAA team and had no history of surgery to their pitching arms. All pitchers underwent a pitching analysis using computerized motion analysis techniques. The forearm’s position, rotational velocity, and supination and pronation moments were analyzed using a random intercept mixed-effects regression model to determine if there were significant associations between the variables of interest and the elbow varus moment. All moments are presented as internal moments.Results:A total of 78 collegiate level pitchers with a mean age of 19.9 ± 1.3 years, were include in this study. The average fastball velocity was 32.1 ± 2.5m/s. The results indicated that there was no association with the forearm’s position or rotational velocity and the elbow varus moment. However, there were statistically significant associations between the forearm supination moment and the elbow varus moment (p=0.002). The results showed that for every 1Nm increase in the supination moment there was a corresponding 1 Nm increase in the elbow varus moment. Whereas a pronation moment was associated with a decrease in the elbow varus moment (p=0.013).Conclusion:The forearm’s absolute position was not associated with an increased elbow varus moment, indicating that the position of the forearm does not play a role in injury mechanisms for baseball pitchers. However the regression analysis indicated a significant association with the forearm moments and the elbow varus moment. Specifically that an increased supination moment increased the elbow varus moment. Therefore as the body resists the pronation motion associated with pitching this increases the stresses on the medial side of the elbow. Suggesting that an increased need to resist pronation in pitchers that over supinate their arms during a pitch could be placing additional stresses on their elbows and therefore increasing their risk for injury. This finding also provides evidence that a potential injury prevention strategy for pitchers could be to increase their forearm supination and reduce the speed at which they pronate especially during the deceleration of the pitch cycle.

Recovery of Wrist Function after Volar Locking Plate Fixation for Distal Radius Fractures

The purpose of our present study was to examine the recovery of the postoperative wrist function, and to compare the range of motion among each direction ofthe wrist joint during the same time periods after surgery for distal radius fractures. Twenty patients treated with a volar locking plate were evaluated. The active range of motion and grip strength were assessed at four weeks, six weeks, three months, six months and one year after surgery. The ratio of the range of motion in pronation and supination recovered significantly earlier than for any other directions within six months after surgery (p = 0.0205), however, the ratio of the range of motion among the six directions was not significantly different at one year after surgery (p = 0.0823). The recovery of the range of motion in flexion was 96.8% compared with the contralateral wrist at one year after surgery, and it was not significantly lower than that in extension, radial deviation or ulnar deviation (97.8%, 93.5%, 94.4%, respectively). The grip strength of dominant hand recovered from 50% after four weeks to 66% after six weeks, 83% after three months, 91% after six months and 106% at the examination performed after one year compared with the uninjured non-dominant hand. The grip strength of non-dominant hand recovered from 52% after four weeks to 59% after six weeks, 79% after three months, 84% after six months and 94% at the examination performed after one year compared with the uninjured dominant hand. The mean DASH score was 5.3. The range of motion in flexion can achieve similar improvement to that in the other directions by obtaining the appropriate postoperative parameters. The optimal postoperative radiographic parameters were thus identified to be essential for successfully obtaining a recovery of the wrist function for unstable distal radius fractures.

Motion Analysis of the Trapeziometacarpal Joint Using Three-dimensional Computed Tomography.

Zancolli theorized that the first metacarpal bone axially rotates on the semispheroidal part of the trapezium, which is controlled by ligaments. This study used three-dimensional computed tomography (3D-CT) to describe the motion of the first metacarpal bone on the trapezium. 3D-CT images were taken of the left hand of 30 healthy volunteers (mean age [Formula: see text] years, 15 men and 15 women). They were divided into five groups: radial abduction, retroposition, adduction, palmar abduction, and opposition. The range of motion of radial abduction and palmar abduction of the trapeziometacarpal joint was measured from the first metacarpal bone to the second metacarpal bone. The range of motion of pronation was measured following Cheema's method. The main contacts of the joint surface of trapezium and the first metacarpal bone were determined on the 3D-CT images. Pronation of the trapeziometacarpal joint was [Formula: see text] in radial abduction, [Formula: see text] in retroposition, [Formula: see text] in adduction, [Formula: see text] in palmar abduction, and [Formula: see text] in opposition. Radial abduction was [Formula: see text] in radial abduction, [Formula: see text] in retroposition, [Formula: see text] in adduction, [Formula: see text] in palmar abduction, and [Formula: see text] in opposition. Palmar abduction was [Formula: see text] in radial abduction, [Formula: see text] in retroposition, [Formula: see text] in adduction, [Formula: see text] in palmar abduction, and [Formula: see text] in opposition. The contact surfaces of the trapezium and the first metacarpal bone were dorsal and ulnar in radial abduction, radial and ulnar in retroposition, and volar-ulnar and volarradial in opposition, respectively, while they were both central in adduction and both radial in palmar abduction. The range of motion of the trapeziometacarpal joint was 44° for radial abduction/adduction, 48° for palmar abduction/adduction, and 57° for pronation/supination. The varying contact surfaces of the trapezium and the first metacarpal bone enabled a wide range of motion.

手関節可動域計測システムの開発

Goniometer and flexible Goniometer are used for measuring range of motion (ROM). However the method of measuring ROM of wrist with Goniometer has many problems. For examples, it can not measure wrist's motion mixed with motion of ulnar and radial flexion and palmar and dorsal flexion, it is difficult for dividing wrist's motion from motion of pronation and supination by arm and it has limitation on measurable ROM due to low elasticity of Goniometer. Therefore, we are developing the new type measurement system for ROM of wrist. In this paper we explain the measurement system for ROM of wrist. And we measure the ROM of healthy parson by using the measurement system. From measured data, we confirmed that measurement system can measure the ROM.

Real time Electronic Control of Multi Fingered Hand Based on Sensors

In India the general population's majority lost their hand because of street mishap, sickness and troopers lost their arm in war. This paper portrays the outline which controls the hand movement and wrist movement of My electric controlled prosthetic arm utilizing cortex M3 microcontroller. In this outline electromyogram signs are created by getting the muscles of biceps and detected by terminal sensors. Anode sensors deliver the electrical signs and these signs are handled by small scale controller and accomplish the supination movement from 0 to 75 and pronation movement from 0 to 85 in the wrist of hand.. In this study, a human five-fingered mechanical hand, activated by six engines, was utilized as a prosthetic hand emulator to evaluate the possibility of a control methodology in light of Principal Components Analysis (PCA), particularly considered to address this issue. Since it was exhibited somewhere else that the initial two foremost parts (PCs) can portray the entire hand setup space adequately well, the controller here utilized returned the PCA calculation and permitted to drive a multi-DoF hand by consolidating a two differential channels EMG information with these two PCs. Consequently, the oddity of this methodology remained in the PCA application for taking care of the testing issue of best mapping the EMG inputs into the degrees of opportunity (DoFs) of the prosthesis

The role of the forelimb in prey capture in the Late Triassic reptile Megalancosaurus (Diapsida, Drepanosauromorpha)

The pectoral girdle and forelimb of the Late Triassic drepanosauromorph reptile Megalancosaurus are redescribed and their function reinterpreted. The whole skeleton of this diapsid is highly specialised for arboreal life, and also the peculiarities of the shoulder girdle and forelimb were interpreted as adaptations for a limb-based locomotion using gap-bridging to move from one support to another, as in chameleons. Re-examination of the pectoral girdle and forelimb revealed the presence of clavicles fused into a furcula-like structure, a saddle-shaped glenoid and a tight connection between the radius and ulna that strengthened the forearm but hindered pronation and supination movements at that joint. The new information plus a reconstruction of the pectoral and forelimb musculature suggests that the forelimb was also specialised for grasping and raking in addition to climbing and thus prey capture may have been an important function for the forelimb. The new functional interpretation fits well with the overall body architecture of Megalancosaurus’ skeleton, suggesting that this reptile was an ambush predator that may have assumed a stable tripodal position, secured by the hooked tail and hind limbs, freeing its forelimbs to catch prey by sudden extension of the arm and firm grasping with the pincer-like digits.

Outcome after Implantation of the Aptis Total Distal Radioulnar Joint Replacement Prosthesis

To date, the Aptis distal radioulnar joint (DRUJ) prosthesis by Scheker is the only total, bipolar prosthesis available. In the literature, only few data exist concerning the prosthesis and its surgical technique. Aim of the present study was the evaluation of the medium-term clinical and radiological outcome following implantation of the Aptis DRUJ prosthesis. 5 patients (4 women and 1 man) with mean age of 40.2 (30-65) years underwent secondary implantation of the Aptisprosthesis between February 2006 and May 2013. The average date of the follow-up was after 36 (24-48) months. Besides the complications, the wrist range of motion (ROM) and the strength in grip were measured. The quality of pain was determined using a visual analogue pain scale from 0-10. In follow-up X-ray controls, bone resorption and bony abnormalities were evaluated. The DASH score as well as the postoperative subjective satisfaction of the patients were recorded. No patient required removal of the prosthesis. Only 1 patient underwent secondary surgery in which debridement of the screw tip over the radius was required. The postoperative range of motion in pronation and supination was measured with 78 (70-90)° and 82 (70-90)°. The average grip strength amounted to 29 (24-32) kg. This represented 85 (76-100)% of the value of the contralateral side. Postoperative pain symptoms on the visual analogue pain scale were measured with 0 points at rest and with 1.2 (0-2) points under strain. Radiological evaluation showed bone resorption at the radial peg in 2 patients, but without evidence of implant loosening. The DASH score was recorded with 37 (13-75) points. All patients were satisfied or very satisfied after the surgical treatment. The Aptis prosthesis is a safe and efficient treatment option for previously failed surgery of the DRUJ.

Sagittal plane blocade chez les patients présentant un hallux limitus fonctionnel (HLF). Résultats après ténolyse endocopique du tendon du long fléchisseur de l’hallux par un modèle multi-segment, une étude comparative et prospective

Functional hallux limitus (Fhl) is a loss of 1st metatarsophalangeal joint extension during the second half of the single-support phase, when the weight-bearing foot is in maximal dorsiflexion, with important consequences during gait. Our objectives were to evaluate the functional results in the sagittal plane biomechanics following the endoscopic release of the Flexor Hallucis Longus (FHL) tendon at the retrotalar pulley, by assessing the kinematics and kinetics of the foot using a multi-segment model. A prospective cohort of 20 patients with FHL was analyzed before and after surgical treatment and compared with 10 healthy subjects comprising the control group. A complete orthopaedic clinical examination was performed. Foot posture was determined with the Foot Posture Index and function before and after surgery was measured with the AOFAS Ankle-Hindfoot and AOFAS Midfoot validated scales. The multi-segment model consisted of Gait and joint angles’ analysis with the use of inertial sensors, plantar pressure analysis and surface electromyography analysis with the use of EMG. Pressure parameters, e.g., peak pressure, maximum force, time of occurrence, and contact time in different foot sub-regions and duration of activation, normalized EMG amplitude, and frequency content of selected muscles of shank were calculated. Results showed an alteration of the gait pattern in the sagittal plane by increasing the flexion moment at the knee and ankle. A diminished dorsal flexion of the great toe at push-off, explaining the failure of the windlass mechanism, was also evident. An alteration of the plantar pressure distribution along the stance phase was associated to a mistimed supination to pronation motion, necessary to gain instability before heel-strike and push-off. FHL causes a sagittal plane blockade, which is usually present at the retrotalar pulley and causes an asynchronic and mistimed gait that changes the biomechanics of the lower limb, especially the foot. Range of motion at the 1st metatarsophalangeal (1MTPJ) joint, ankle and knee joints are comparable to control group values, indicating the restoration of gait biomechanics following the endoscopic release of the FHL. Even though not statistically significant, the existent changes in the angular velocity values of the lower limb, especially below the knee, illustrate the involvement of a delayed muscular activation which is a time dependent factor. Endoscopic FHL release is a safe and promising treatment alternative for 1MTPJ pathologies that restores normal gait and minimizes the occurrence of associated degenerative sequelae. Further studies including larger cohort groups are warranted.

English

BACKGROUND: Intraarticular displaced distal humerus fractures in adults always require open reduction and internal fixation with some plate and screw osteosynthesis after accurate reduction and alignment of fracture fragments. But high velocity trauma or gun-shot injuries often lead to a compound fracture with contamination and devitalization of soft tissue cover which requires some kind of external fixation. We thereby report the outcome of a series of ten patients who were treated definitively by extensive debridement and JESS type external fixation. This external fixator construct gave excellent fracture fragment stability and early mobilization of elbow joint. It provided patient friendly definitive fixation assembly resulting in early fracture consolidation with reasonably good range of elbow movement for such difficult fractures. MATERIAL AND METHODS: Ten cases of compound intercondylar distal humerus fracture between January 2007 to December 2011were treated by early debridement & uniplanar bilateral JESS fixator application at the same sitting. This study includes cases of age group 1865 yrs. of which 3 were females & 7 were males. Mean age was 31.5yr. Only one case had injury to elbow with Gun-shot injury & rest were of high energy road traffic accidents. All patients reported within 40 hrs. average time to emergency department except 2 cases. A case of Gun-shot injury reported after 5 days & one case reported after 7day with pus discharge wound. According to A.O. Classification, 4 cases with C 3 type& 6 were C 2 type. All cases were operated within a mean of 8.7hrs of presenting to the emergency department. The average interval between injury & operation was 48.7 hrs. RESULTS: Complete painless supination pronation movement was achieved in six weeks At the end of six months of aggressive physiotherapy, the average extension was 9 degrees (range = 5 – 15 degrees) and average flexion was 106 degrees (range = 70 – 120 degrees). Clinical evaluation of elbow functions was done at sixth month using Mayo elbow score where 20% excellent, 60% good, 10%fair and10% poor results were obtained. CONCLUSION: This is a relatively new technique of fixing compound intra-articular distal humerus fractures with JESS external fixator without spanning and immobilizing elbow joint has given good results, good patient compliance, least complications in our series of ten cases.

Gross anatomy of skeleton antebrachii of a tiger (Panthera tigris)

Gross anatomical features of the skeleton of forearm of an adult tiger revealed that the ulna was longer and more massive than the radius and was the longest bone of the forelimb. The oval caput radii showed concave fovea capitis radii for humerus and a convex articular circumference for ulna. Radial tuberosity was situated ventrolateral to the caput. A transverse crest extended obliquely from the radial tuberosity ventromedially along the caudal surface of the radius. The olecranon tuberosity of ulna was grooved and presented three prominences of which the caudal one was large and rounded. The shaft of ulna presented a rough, elevated margointer osseus along the cranial surface. The spatium interosseum was wide. The radius and ulna were not fused allowing pronation and supination movements to clutch the prey with the powerful forelimbs.

The c.429_452 duplication of the ARX gene: a unique developmental-model of limb kinetic apraxia

BackgroundThe c.429_452dup24 of the ARX gene is a rare genetic anomaly, leading to X-Linked Intellectual Disability without brain malformation. While in certain cases c.429_452dup24 has been associated with specific clinical patterns such as Partington syndrome, the consequence of this mutation has been also often classified as “non-specific Intellectual Disability”. The present work aims at a more precise description of the clinical features linked to the c.429_452dup24 mutation.MethodsWe clinically reviewed all affected patients identified in France over a five-year period, i.e. 27 patients from 12 different families. Detailed cognitive, behavioural, and motor evaluation, as well as standardized videotaped assessments of oro-lingual and gestural praxis, were performed. In a sub-group of 13 ARX patients, kinematic and MRI studies were further accomplished to better characterize the motor impairment prevalent in the ARX patients group. To ensure that data were specific to the ARX gene mutation and did not result from low-cognitive functioning per se, a group of 27 age- and IQ-matched Down syndrome patients served as control.ResultsNeuropsychological and motor assessment indicated that the c.429_452dup24 mutation constitutes a recognizable clinical syndrome: ARX patients exhibiting Intellectual Disability, without primary motor impairment, but with a very specific upper limb distal motor apraxia associated with a pathognomonic hand-grip. Patients affected with the so-called Partington syndrome, which involves major hand dystonia and orolingual apraxia, exhibit the most severe symptoms of the disorder. The particular “reach and grip” impairment which was observed in all ARX patients, but not in Down syndrome patients, was further characterized by the kinematic data: (i) loss of preference for the index finger when gripping an object, (ii) major impairment of fourth finger deftness, and (iii) a lack of pronation movements. This lack of distal movement coordination exhibited by ARX patients is associated with the loss of independent digital dexterity and is similar to the distortion of individual finger movements and posture observed in Limb Kinetic Apraxia.ConclusionThese findings suggest that the ARX c.429_452dup24 mutation may be a developmental model for Limb Kinetic Apraxia.

Entheseal Changes and Functional Implications of the Humeral Medial Epicondyle

ABSTRACTLongitudinal rotation of the forearm (pronosupination) is an essential component of human manipulative tasks. The efficiency of this movement is dependent not only on the rotatory muscles but also on several morphological and structural features of the upper limb. In a recent study, we observed that the size and orientation of the humeral medial epicondyle played an important role in forearm rotatory ability. We further observed that the forearm muscular activity, specifically the motion of pronation, promotes radial curvature, which, in turn, enhances rotational efficiency. In this study, we aim to test whether the orientation of the medial epicondyle is an activity‐dependent parameter or whether it is an invariable morphological feature characteristic of the human skeleton. We analysed the upper limb entheseal changes in 30 human skeletons and assessed the role of several functional groups in the anteroposterior and proximo‐distal orientation of the medial epicondyle. Our results indicate that the orientation of the medial epicondyle is partially an activity‐dependent feature basically determined by elbow flexor‐extensors and hand and wrist flexors. The orientation of the medial epicondyle towards more posterior and proximal positions causes a gain of efficiency in the pronation range when the elbow is extended and in the supination range when the elbow is flexed. Therefore, we suggest that the medial epicondyle of the humerus is a structure involved in the manipulative capacities of the human upper limb, and its orientation presents a range of variation that may be associated with the functional enhancement of these abilities. Copyright © 2012 John Wiley & Sons, Ltd.

Kinematics of the ankle and foot. In vivo roentgen stereophotogrammetry.

Roentgen stereophotogrammetric analysis has been used to study ankle/foot kinematics in eight healthy volunteers. All the joints between the tibia and the first metatarsal as well as the talo-calcaneal and tibio-fibular joints were analysed in input plantar flexion/dorsiflexion and pronation/supination of the foot as well as internal/external rotation of the leg. The findings included the following: INDIVIDUAL JOINTS 1. The joint axis of the talo-crural joint varied with varying kinds of input motion. Substantial amounts of rotation occurred about axes close to the vertical; this occurred particularly when the input motion was in the internal rotation part of the arc of leg rotation and in pro-/supination of the foot. 2. The total amount of rotation in the talo-calcaneal joint was small in internal rotation of the leg and in pronation of the foot compared to external rotation of the leg and supination of the foot. 3. The talo-navicular joint showed a limited ball-and-socket joint pattern in all subjects. The total amounts of rotation were larger than in the talo-calcaneal joint in all subjects. Plantar flexion axes were more transverse than the axes seen in other kinds of input motion. 4. The talo-calcaneal and talo-navicular joint axes were seldom parallel, indicating that these joints do not necessarily behave as a simple hinge. JOINT INTERACTION Joint interaction varied in different qualities of input motion. Plantar flexion induced rotation in the talo-crural joint, and to some extent in the joints of the arch. Dorsiflexion mainly induced talo-crural joint motion. Pronation/supination induced motion in all joints. The distal joints of the arch displayed more rotation in pronation than in supination, while the talo-calcaneal joint showed less motion in pronation than in supination. Internal leg rotation induced little rotation in the joints of the ankle/foot complex. External rotation induced external rotation, dorsiflexion, and supination in the talo-navicular and talo-calcaneal joints. The distal joints of the arch displayed compensatory plantar flexion and pronation. TRANSFERRAL OF ROTATION The ankle/foot complex showed ability to transform leg rotation into pro-/supination and vice versa. This function was most pronounced in external leg rotation. MOTIONS OF THE FIBULA The fibula showed consistent lateral and posterior translation from input plantar flexion to dorsiflexion of the foot.

Realisation of SEMG-based multifunctional prototype elbow prosthesis

Prosthetic devices employing myoelectric control systems are now widely accepted by upper-limb-deficient individuals. However, such devices are successfully fitted to below-elbow amputees to control a single function-opening or closing a prosthetic hand. In above-elbow amputees, the multifunctional control of artificial prosthetic device using myoelectric signals is of major importance. In this work, RMS value (Vrms) of SEMG was used to realise microcontroller-based artificial elbow. Microcontroller-based artificial elbow was designed to carter four elbow operations, i.e., elbow flexion, extension, pronation and supination movements. Myoelectric signals were recorded using Ag-AgCl surface electrodes from biceps and triceps branchii. A prototype was developed with control from single-channel and two-channel approaches.

Indices of Evaluation System for a Motion of Pronation and Supination of Forearms using Three-Dimensional Wireless Acceleration and Angular Velocity Sensors

Indices of Evaluation System for a Motion of Pronation and Supination of Forearms using Three-Dimensional Wireless Acceleration and Angular Velocity Sensors