Der Regelkreis des Kniesehnenreflexes bei der Stabheuschrecke Carausius morosus: Reaktionen auf passive Bewegungen der Tibia

1. Passive flexion and extension of the femur-tibia-joint causes forces which are directed against the passive movements. Quantitative measurements of these forces are in accordance with the results obtained from step stimuli in open-loop-experiments (1965, 1972). Repetition of the experiments at the same joint often leads to different results: the animal is apparently able to change the amplification of the system.
2. If one brings the joint in a new position by hand, the tibia returns to its starting-point only very slowly. (Flexibilitas cerea). As a quantitative measure for Flexibilitas cerea the time interval is taken, during which a formerly fully extended joint returns to the 90°-position after a 30 sec flexion to 50° (t ₉₀) · t ₉₀ is not correllated with a quantitative measure of Thanatosis. Therefore it is not allowed to combine Thanatosis and Flexibilitas cerea to Katalepsis. — Legs whose receptor tendons were cut, show no Flexibilitas cerea. The behaviour of Flexibilitas cerea is explained by the attributes of the control system.
3. The reaction on very slow constant flexion and extension speeds (2,4°/sec – 0,3°/min) are described. Intact legs show a larger hysteresis at all speeds than legs with cut receptor tendons: it seems the control system reacts at those slow speeds. It responds only to the dynamic part of the movements, however not to the static one.

     

Ultrasonographic observations of the maturation of basic movements in guinea pig fetuses

Ultrasonography has not previously been used for studying fetal movements in precocial rodents. The objective of this study was to ultrasonographically determine the sequence of the appearance of basic movements in a guinea pig fetus. The research included eight guinea pig females carrying one fetus each. Fetal movements were observed for 10 minutes each day, from the 25th to 38th day of gestation. The time and sequence of the appearance of movements was observed as follows: whole body flexion (mean 27.6 SD ± 1.68), whole body extension (mean 28.1 SD ± 1.12), head flexion (mean 28.1 SD ± 1.80), head extension (mean 30.5 SD ± 2.67) forelimbs flexion (mean 30.5 SD ± 2.32), forelimbs extension (mean 30.7 SD ± 1.84), trunk rotation (mean 31.9 SD ± 2.23), forelimbs alternating flexion and extension (mean 32.1 SD ± 2.1), hind limbs extension (mean 32.2 SD ± 3.2), hind limbs flexion (mean 32.4 SD ± 3.16), and hind limbs alternating flexion and extension (mean 33.5 SD ± 2.39). The identical sequences of basic movement appearances in guinea pigs, sheep, and rats suggest that the rostrocaudal gradient of basic movement appearance could be a general developmental pattern in mammalian species.     

Partial medial meniscectomy and rotational differences at the knee during walking

Loss of meniscal function due to injury or partial meniscectomy is common and represents a significant risk factor for premature osteoarthritis. The menisci can influence the transverse plane movements (anterior–posterior (AP) translation and internal–external (IE) rotation) of the knee during walking. While walking is the most frequent activity of daily living, the kinematic differences at the knee during walking associated with the meniscal injury are not well understood. This study examined the influence of partial medial meniscectomy (PMM) on the kinematics and kinetics of the knee during the stance phase of gait by testing the differences in anterior–posterior translation, internal–external rotation, knee flexion range of movement, peak flexion/extension moments, and adduction moments between the PMM and healthy contralateral limbs. Ten patients (45±9 years old, height 1.75±0.06 m, weight 76.7±13.5 kg) who had undergone partial medial meniscectomy (33±100 months post-op) in one limb with a healthy contralateral limb were tested during normal walking. The contralateral limb was compared to a matched control group and no differences were found. The primary kinematic difference was a significantly greater external rotation (3.2°) of the tibia that existed through stance phase, with 8 of 10 subjects demonstrating the same pattern. The PMM subjects also exhibited significantly lower peak flexion and extension moments in their PMM limbs. The altered rotational position found likely results in changes of tibio-femoral contact during walking and could cause the type of degenerative changes found in the articular cartilage following meniscal injury.     

Age-related and obstacle height-related differences in movements while stepping over obstacles

Background

This study aims to examine age-related and obstacle height-related differences in movements while stepping over obstacles.

Methods

The participants included 16 elderly and nine young women. Obstacles that were either 5 or 20 cm high were positioned at the center of a 4-m walking path. The participants were instructed to walk along the path as quickly as possible. The participants’ movements were analyzed using a three-dimensional motion analysis system that recorded their movements as they walked and stepped over the obstacles.

Results and conclusions

Seven joint angles and the distances between the ground and six markers were examined in the initial contact and swing instants of the leading and trailing limbs. In the initial contact instant, the elderly women prepared for stepping with a lower toe height than the young women when stepping over the 20-cm obstacle. Trunk rotation was greater in the young women than in the elderly women. In the swing instant, the elderly women showed greater ankle dorsiflexion and hip adduction angles for the leading limb when stepping over the 20-cm obstacle. They moved the trailing limb with increased ankle dorsiflexion, knee flexion, hip flexion, and foot inversion to ensure that they did not touch the obstacle as they stepped over it. These movement patterns are characteristic of elderly individuals who cannot easily lift their lower limbs because of decreased lower-limb strength.     

Women with knee osteoarthritis have more pain and poorer function than men, but similar physical activity prior to total knee replacement

Background

Osteoarthritis of the knee is a major clinical problem affecting a greater proportion of women than men. Women generally report higher pain intensity at rest and greater perceived functional deficits than men. Women also perform worse than men on function measures such as the 6-minute walk and timed up and go tests. Differences in pain sensitivity, pain during function, psychosocial variables, and physical activity levels are unclear. Further the ability of various biopsychosocial variables to explain physical activity, function and pain is unknown.

Methods

This study examined differences in pain, pain sensitivity, function, psychosocial variables, and physical activity between women and men with knee osteoarthritis (N = 208) immediately prior to total knee arthroplasty. We assessed: (1) pain using self-report measures and a numerical rating scale at rest and during functional tasks, (2) pain sensitivity using quantitative sensory measures, (3) function with self-report measures and specific function tasks (timed walk, maximal active flexion and extension), (4) psychosocial measures (depression, anxiety, catastrophizing, and social support), and (5) physical activity using accelerometry. The ability of these mixed variables to explain physical activity, function and pain was assessed using regression analysis.

Results

Our findings showed significant differences on pain intensity, pain sensitivity, and function tasks, but not on psychosocial measures or physical activity. Women had significantly worse pain and more impaired function than men. Their levels of depression, anxiety, pain catastrophizing, social support, and physical activity, however, did not differ significantly. Factors explaining differences in (1) pain during movement (during gait speed test) were pain at rest, knee extension, state anxiety, and pressure pain threshold; (2) function (gait speed test) were sex, age, knee extension, knee flexion opioid medications, pain duration, pain catastrophizing, body mass index (BMI), and heat pain threshold; and (3) physical activity (average metabolic equivalent tasks (METS)/day) were BMI, age, Short-Form 36 (SF-36) Physical Function, Kellgren-Lawrence osteoarthritis grade, depression, and Knee Injury and Osteoarthritis Outcome Score (KOOS) pain subscale.

Conclusions

Women continue to be as physically active as men prior to total knee replacement even though they have significantly more pain, greater pain sensitivity, poorer perceived function, and more impairment on specific functional tasks.     

Biomechanical influence of TKA designs with varying radii on bilateral TKA patients during sit-to-stand

Background

Compared to the design of a traditional multi-radius (MR) total knee arthroplasty (TKA), the single-radius (SR) implant investigated has a fixed flexion/extension center of rotation. The biomechanical effectiveness of an SR for functional daily activities, i.e., sit-to-stand, is not well understood. The purpose of the study was to compare the biomechanics underlying functional performance of the sit-to-stand (STS) movement between the limbs containing an MR and an SR TKA of bilateral TKA participants.

Methods

Sagittal plane kinematics and kinetics, and EMG data for selected knee flexor and extensor muscles were analyzed for eight bilateral TKA patients, each with an SR and an MR TKA implant.

Results

Compared to the MR limb, the SR limb demonstrated greater peak antero-posterior (AP) ground reaction force, higher AP ground reaction impulse, less vastus lateralis and semitendinosus EMG during the forward-thrust phase of the STS movement. No significant difference of knee extensor moment was found between the two knees.

Conclusion

Some GRF and EMG differences were evident between the MR and SR limbs during STS movement. Compensatory adaptations may be used to perform the STS.

     

Relationships between biomarkers of cartilage, bone, synovial metabolism and knee pain provide insights into the origins of pain in early knee osteoarthritis

Introduction

We tested the hypothesis that there exist relationships between the onset of early stage radiographically defined knee osteoarthritis (OA), pain and changes in biomarkers of joint metabolism.

Methods

Using Kellgren-Lawrence (K/L) grading early radiographic knee OA (K/L 2) was detected in 16 of 46 patients. These grades (K/L 1 is no OA and K/L 2 is early OA) were divided into two groups according to the presence or absence of persistent knee pain. Sera (s) and urines (u) were analysed with biomarkers for cartilage collagen cleavage (sC2C and uCTX-II) and synthesis (sCPII), bone resorption (uNTx) and synovitis (hyaluronic acid: sHA).

Results

sCPII decreased and sC2C/sCPII, uCTX-II/sCPII and sHA increased with onset of OA (K/L 2 versus K/L 1) irrespective of joint pain. In contrast, sC2C and uCTX-II remained unchanged in early OA patients. Of the patients with K/L grades 1 and 2 sC2C, sCPII, sHA, uNTX and uCTX-II were all significantly increased in patients with knee pain independent of grade. Among the K/L grade 2 subjects, only uCTX-II and uCTX-II/sCPII were increased in those with knee pain. In grade 1 patients both sC2C and sCPII were increased in those with knee pain. No such grade specific changes were seen for the other biomarkers including sHA.

Conclusions

These results suggest that changes in cartilage matrix turnover detected by molecular biomarkers may reflect early changes in cartilage structure that account directly or indirectly for knee pain. Also K/L grade 1 patients with knee pain exhibit biomarker features of early OA.     

Promising potential of new generation translocator protein tracers providing enhanced contrast of arthritis imaging by positron emission tomography in a rat model of arthritis

Introduction

The role of popliteal cysts and subgastrocnemius bursitis in knee joint homeostasis is uncertain. The aim of this study is to describe cross-sectional associations between popliteal cysts, subgastrocnemius bursitis, knee symptoms and structural abnormalities in older adults.

Methods

A cross-sectional sample of 900 randomly-selected subjects (mean age 63 years, 48% female) were studied. Knee pain, stiffness and dysfunction were assessed by self-administered Western Ontario McMaster Osteoarthritis Index (WOMAC) questionnaire. Radiographic knee osteophyte and joint space narrowing (JSN) were recorded. Magnetic resonance imaging (MRI) was utilized to assess popliteal cysts, subgastrocnemius bursitis, cartilage defects and bone marrow lesions (BMLs).

Results

Popliteal cysts were present in 11.7% and subgastrocnemius bursitis in 12.7% of subjects. Subgastrocnemius bursitis was more common in those with popliteal cyst (36.2% versus 9.7%, P <0.01). In multivariable analyses, popliteal cysts were significantly associated with increased osteophytes in both medial and lateral tibiofemoral compartments while subgastrocnemius bursitis was associated with increased osteophytes and JSN in the medial tibiofemoral compartment. Both were significantly associated with cartilage defects in all compartments, and with BMLs in the medial tibiofemoral compartment. Furthermore, both popliteal cysts and subgastrocnemius bursitis were significantly associated with increased weight-bearing knee pain but these associations became non-significant after adjustment for cartilage defects and BMLs.

Conclusions

Popliteal cysts and subgastrocnemius bursitis are associated with increased symptoms as well as radiographic and MRI-detected joint structural abnormalities. Longitudinal data will help resolve if they are a consequence or a cause of knee joint abnormalities.     

Functional measurements based on feature tracking of cine magnetic resonance images identify left ventricular segments with myocardial scar

Background

New sensors for intelligent remote monitoring of the heart should be developed. Recently, a cutaneous force-frequency relation recording system has been validated based on heart sound amplitude and timing variations at increasing heart rates.

Aim

To assess sensor-based post-exercise contractility, diastolic function and pressure in normal and diseased hearts as a model of a wireless telemedicine system.

Methods

We enrolled 150 patients and 22 controls referred for exercise-stress echocardiography, age 55 ± 18 years. The sensor was attached in the precordial region by an ECG electrode. Stress and recovery contractility were derived by first heart sound amplitude vibration changes; diastolic times were acquired continuously. Systemic pressure changes were quantitatively documented by second heart sound recording.

Results

Interpretable sensor recordings were obtained in all patients (feasibility = 100%). Post-exercise contractility overshoot (defined as increase > 10% of recovery contractility vs exercise value) was more frequent in patients than controls (27% vs 8%, p < 0.05). At 100 bpm stress heart rate, systolic/diastolic time ratio (normal, < 1) was > 1 in 20 patients and in none of the controls (p < 0.01); at recovery systolic/diastolic ratio was > 1 in only 3 patients (p < 0.01 vs stress). Post-exercise reduced arterial pressure was sensed.

Conclusion

Post-exercise contractility, diastolic time and pressure changes can be continuously measured by a cutaneous sensor. Heart disease affects not only exercise systolic performance, but also post-exercise recovery, diastolic time intervals and blood pressure changes – in our study, all of these were monitored by a non-invasive wearable sensor.     

3D Sequential Kinematics of the Femoro-Tibial Joint of Normal Knee from Multiple Bi-planar X-rays: Accuracy and Repeatability

Background

Several methods can be used to assess joint kinematics going from optoelectronic motion analysis to biplanar fluoroscopy. The aim of the present work was to evaluate the reliability of the use of biplane radiography to quantify the sequential 3D kinematics of the femoro-tibial joint.

Diastolic time – frequency relation in the stress echo lab: filling timing and flow at different heart rates

 

A cutaneous force-frequency relation recording system based on first heart sound amplitude vibrations has been recently validated. Second heart sound can be simultaneously recorded in order to quantify both systole and diastole duration.

Aims

1- To assess the feasibility and extra-value of operator-independent, force sensor-based, diastolic time recording during stress.

Methods

We enrolled 161 patients referred for stress echocardiography (exercise 115, dipyridamole 40, pacing 6 patients). The sensor was fastened in the precordial region by a standard ECG electrode. The acceleration signal was converted into digital and recorded together with ECG signal. Both systolic and diastolic times were acquired continuously during stress and were displayed by plotting times vs. heart rate. Diastolic filling rate was calculated as echo-measured mitral filling volume/sensor-monitored diastolic time.

Results

Diastolic time decreased during stress more markedly than systolic time. At peak stress 62 of the 161 pts showed reversal of the systolic/diastolic ratio with the duration of systole longer than diastole. In the exercise group, at 100 bpm HR, systolic/diastolic time ratio was lower in the 17 controls (0.74 ± 0.12) than in patients (0.86 ± 0.10, p < 0.05 vs. controls). Diastolic filling rate increased from 101 ± 36 (rest) to 219 ± 92 ml/m²* s^-1 at peak stress (p < 0.5 vs. rest).

Conclusion

Cardiological systolic and diastolic duration can be monitored during stress by using an acceleration force sensor. Simultaneous calculation of stroke volume allows monitoring diastolic filling rate. Stress-induced "systolic-diastolic mismatch" can be easily quantified and is associated to several cardiac diseases, possibly expanding the spectrum of information obtainable during stress.     

Chondrocalcinosis is common in the absence of knee involvement

Introduction

We aimed to describe the distribution of radiographic chondrocalcinosis (CC) and to examine whether metacarpophalangeal joint (MCPJ) calcification and CC at other joints occurs in the absence of knee involvement.

Methods

This was a cross-sectional study embedded in the Genetics of Osteoarthritis and Lifestyle study (GOAL). All participants (n = 3,170) had radiographs of the knees, hands, and pelvis. These were scored for radiographic changes of osteoarthritis (OA), for CC at knees, hips, symphysis pubis, and wrists, and for MCPJ calcification. The prevalence of MCPJ calcification and CC overall, at each joint, and in the presence or absence of knee involvement, was calculated.

Results

The knee was the commonest site of CC, followed by wrists, hips, and symphysis pubis. CC was more likely to be bilateral at knees and wrists but unilateral at hips. MCPJ calcification was usually bilateral, and less common than CC at knees, hips, wrists, and symphysis pubis. Unlike that previously reported, CC commonly occurred without any knee involvement; 44.4% of wrist CC, 45.9% of hip CC, 45.5% of symphysis pubis CC, and 31.3% of MCPJ calcification occurred in patients without knee CC. Those with meniscal or hyaline articular cartilage CC had comparable ages (P = 0.21), and neither preferentially associated with fibrocartilage CC at distant joints.

Conclusions

CC visualized on a plain radiograph commonly occurs at other joints in the absence of radiographic knee CC. Therefore, knee radiographs alone are an insufficient screening test for CC. This has significant implications for clinical practice, for epidemiologic and genetic studies of CC, and for the definition of OA patients with coexistent crystal deposition.     

SPEM dysfunction and general schizotypy as measured by the SSQ: a controlled study

Background

SPEM dysfunction is a well-known phenomenon in schizophrenia. The principal aim of the present study was to examine whether SPEM dysfunction is already observable in subjects scoring high on a specific measure of schizotypy (SSQ General Schizotypy) that was selected because of its intimate relationship with schizophrenic prodromal unfolding.

Methods

Applying ANOVAs, we determined the relationship of subjects' scores on SSQ General Schizotypy and eye movements elicited by targets of different speed. We also examined whether there exists an association between our schizotypy measure and pupil size.

Results

We found more SPEM dysfunction in subjects scoring high on SSQ General Schizotypy than in subjects scoring average on that factor, irrespective of the speed of the target. No relationship was found between baseline pupil size and General Schizotypy.

Conclusion

The present study provides additional evidence that SPEM dysfunction is associated with schizotypic features that precede the onset of schizophrenia and is already observable in general population subjects that show these features.     

Hemicraniectomy after middle cerebral artery infarction with life-threatening Edema trial (HAMLET). Protocol for a randomised controlled trial of decompressive surgery in space-occupying hemispheric infarction

Background

Thirty thousand knee replacements are performed annually in the UK. There is uncertainty as to the best surgical approach to the knee joint for knee arthroplasty. We planned a randomised controlled trial to compare a standard medial parapatellar arthrotomy with sub-vastus arthrotomy for patients undergoing primary total knee arthroplasty in terms of short and long term knee function.

Methods

Patients undergoing primary total knee arthroplasty at the local NHS Trust are to be recruited into the study. Patients are to be randomised into either the subvastus or medial parapatellar approache to knee arthroplasty. The primary outcome measures will be the American Knee Society and WOMAC Scores. The secondary outcome measures will be patient based measures of EuroQol and SF-36. All outcomes will be measured pre-operatively, 1, 6, 12 and 52 weeks post-operatively. We will also review pain intensity using a pain and analgesia diary. Ease of surgical exposure and complications will also be analysed.

Discussion

Evidence is lacking concerning the best surgical approach to the knee joint for patients undergoing primary total knee replacement. This pragmatic randomised trial tests the hypothesis that the sub-vastus approach is significantly superior to the standard medial parapatellar approach in terms of short and long term knee function.     

Cross-Talk Correction Method for Knee Kinematics in Gait Analysis Using Principal Component Analysis (PCA): A New Proposal

Background

In 3D gait analysis, the knee joint is usually described by the Eulerian way. It consists in breaking down the motion between the articulating bones of the knee into three rotations around three axes: flexion/extension, abduction/adduction and internal/external rotation. However, the definition of these axes is prone to error, such as the “cross-talk” effect, due to difficult positioning of anatomical landmarks. This paper proposes a correction method, principal component analysis (PCA), based on an objective kinematic criterion for standardization, in order to improve knee joint kinematic analysis.

Methods

The method was applied to the 3D gait data of two different groups (twenty healthy subjects and four with knee osteoarthritis). Then, this method was evaluated with respect to three main criteria: (1) the deletion of knee joint angle cross-talk (2) the reduction of variance in the varus/valgus kinematic profile (3) the posture trial varus/valgus deformation matching the X-ray value for patients with knee osteoarthritis. The effect of the correction method was tested statistically on variabilities and cross-talk during gait.

Results

Cross-talk was lower (p<0.05) after correction (the correlation between the flexion-extension and varus-valgus kinematic profiles being annihilated). Additionally, the variance in the kinematic profile for knee varus/valgus and knee flexion/extension was found to be lower and higher (p<0.05), respectively, after correction for both the left and right side. Moreover, after correction, the posture trial varus/valgus angles were much closer to x-ray grading.

Conclusion

The results show that the PCA correction applied to the knee joint eliminates the cross-talk effect, and does not alter the radiological varus/valgus deformation for patients with knee osteoarthritis. These findings suggest that the proposed correction method produces new rotational axes that better fit true knee motion.     

Joint-specific power production and fatigue during maximal cycling

Cycling power decreases substantially during a maximal cycling trial of just 30 s. It is not known whether movement patterns and joint powers produced at each joint decrease to a similar extent or if each joint exhibits an individual fatigue profile. Changes in movement patterns and/or joint powers associated with overall task fatigue could arise from several different mechanisms or from a complex interplay of these mechanisms. The purpose of this investigation was to determine the changes in movement and power at each joint during a fatiguing cycling trial. Thirteen trained cyclists performed a 30 s maximal cycling trial on an isokinetic cycle ergometer at 120 rpm. Pedal forces and limb kinematics were recorded. Joint powers were calculated using a sagittal plane inverse dynamics model and averaged for the initial, middle, and final three second intervals of the trial, and normalized to initial values. Relative ankle plantar flexion power was significantly less than all other joint actions at the middle interval (51±5% of initial power; p=0.013). Relative ankle plantar flexion power for the final interval (37±3%) was significantly less than the relative knee flexion and hip extension power (p=0.010). Relative knee extension power (41±5%) was significantly less than relative hip extension power (55±4%) during the final three second interval (p=0.045). Knee flexion power (47±5%) did not differ from relative hip extension power (p=0.06). These changes in power were accompanied by a decrease in time spent extending by each joint with fatigue (i.e., decreased duty cycle, p<0.03). While central mechanisms may have played a role across all joints, because the ankle fatigued more than the hip and knee joints, either peripheral muscle fatigue or changes in motor control strategies were identified as the potential mechanisms for joint-specific fatigue during a maximal 30 s cycling trial.     

Sensory and sympathetic nerve fibers undergo sprouting and neuroma formation in the painful arthritic joint of geriatric mice

Introduction

Although the prevalence of arthritis dramatically increases with age, the great majority of preclinical studies concerning the mechanisms that drive arthritic joint pain have been performed in young animals. One mechanism hypothesized to contribute to arthritic pain is ectopic nerve sprouting; however, neuroplasticity is generally thought to be greater in young versus old nerves. Here we explore whether sensory and sympathetic nerve fibers can undergo a significant ectopic nerve remodeling in the painful arthritic knee joint of geriatric mice.

Methods

Vehicle (saline) or complete Freund's adjuvant (CFA) was injected into the knee joint of 27- to 29-month-old female mice. Pain behaviors, macrophage infiltration, neovascularization, and the sprouting of sensory and sympathetic nerve fibers were then assessed 28 days later, when significant knee-joint pain was present. Knee joints were processed for immunohistochemistry by using antibodies raised against CD68 (monocytes/macrophages), PECAM (endothelial cells), calcitonin gene-related peptide (CGRP; sensory nerve fibers), neurofilament 200 kDa (NF200; sensory nerve fibers), tyrosine hydroxylase (TH; sympathetic nerve fibers), and growth-associated protein 43 (GAP43; nerve fibers undergoing sprouting).

Results

At 4 weeks after initial injection, CFA-injected mice displayed robust pain-related behaviors (which included flinching, guarding, impaired limb use, and reduced weight bearing), whereas animals injected with vehicle alone displayed no significant pain-related behaviors. Similarly, in the CFA-injected knee joint, but not in the vehicle-injected knee joint, a remarkable increase was noted in the number of CD68⁺ macrophages, density of PECAM⁺ blood vessels, and density and formation of neuroma-like structures by CGRP⁺, NF200⁺, and TH⁺ nerve fibers in the synovium and periosteum.

Conclusions

Sensory and sympathetic nerve fibers that innervate the aged knee joint clearly maintain the capacity for robust nerve sprouting and formation of neuroma-like structures after inflammation/injury. Understanding the factors that drive this neuroplasticity, whether this pathologic reorganization of nerve fibers contributes to chronic joint pain, and how the phenotype of sensory and sympathetic nerves changes with age may provide pharmacologic insight and targets for better controlling aging-related joint pain.     

Neurotransmitter system markers in adult barrel field

Abstract

Purpose: Skin contributes to joint position sense (JPS) at multiple joints. Altered cutaneous input at the foot can modulate gait and balance and kinesiology tape can enhance proprioception at the knee, but its effect may be dependent on existing capacity. The effect of texture at the knee, particularly in those with poor proprioception, is unknown. The aim of this study was to determine the effect of textured panels on JPS about the knee.

Materials and methods: Eighteen healthy females were seated in an adjustable chair. Their left leg (target limb) moved passively from 65° to a target of flexion (115° or 90°) or extension (40°). Their right leg (matching limb) was passively moved towards this target angle and participants indicated when their limbs felt aligned. We tested three textured panels over the knee of the matching limb and two control conditions. The target limb maintained a control panel. Directional error, absolute error and variable error in matching between limbs were calculated.

Results: On average textured panels over the knee increased JPS error compared to control pants for participants with poor JPS. These participants undershot the target at 90° of flexion significantly more with textured panels (?11°?±?3°) versus control (?7°?±?3°, p?=?0.04).

Conclusions: For participants with poor JPS accuracy, increased JPS error at 90° with a textured panel suggests these individuals utilised altered cutaneous information to adjust joint position. We propose increased error results from enhanced skin input at the knee leading to the perception of increased flexion.     

Magnetic resonance imaging of the erector spinae muscles in Duchenne muscular dystrophy: implication for scoliotic deformities

Background

In patients with structural idiopathic scoliosis the body asymmetries involve the pelvis and the lower limbs; they are included in many theories debating the pathogenesis of idiopathic scoliosis.

Methods

Hip joint range of motion was studied in 158 adolescent girls, aged 10–18 years (mean 14.2 ± 2.0) with structural idiopathic scoliosis of 20–83° of Cobb angle (mean 43.0° ± 14.5°) and compared to 57 controls, sex and age matched. Hip range of rotation was examined in prone position, the pelvis level controlled with an inclinometer; hip adduction was tested in five different positions.

Results

In girls with structural scoliosis the symmetry of hip rotation was less frequent (p = 0.0047), the difference between left and right hip range of internal rotation was significantly higher (p = 0.0013), and the static rotational offset of the pelvis, calculated from the mid-points of rotation, revealed significantly greater (p = 0.0092) than in healthy controls. The detected asymmetries comprised no limitation of hip range of motion, but a transposition of the sector of motion, mainly towards internal rotation in one hip and external rotation in the opposite hip. The data failed to demonstrate the curve type, the Cobb angle, the angle of trunk rotation or the curve progression factor to be related to the hip joint asymmetrical range of motion.

Conclusion

Numerous asymmetries around the hip were detected, most of them were expressed equally in scoliotics and in controls. Pathogenic implications concern producing a "torsional offset" of muscles patterns of activation around the spine in adolescent girls with structural idiopathic scoliosis during gait.