Bente Rona Jensen

Knee function in 10-year-old children and adults with Generalised Joint Hypermobility.

PURPOSEnKnee function is reduced in patients with Benign Joint Hypermobility Syndrome. The aim was to study knee function in children and adults with Generalised Joint Hypermobility (GJH) and Non-GJH (NGJH)).nnnMATERIALS AND METHODSnIn a matched comparative study, 39 children and 36 adults (mean age children 10.2 years; adults 40.3 years) were included, comprising 19 children and 18 adults with GJH (Beighton ≥ 5/9; Beighton ≥ 4/9), minimum one hypermobile knee, no knee pain (children), and 20 children and 18 adults with NGJH (Beighton <5; Beighton <4). Totally, 85% of the adults were parents to these children. Knee function was determined by self-reported physical fitness (100mm VAS), Knee injury and Osteoarthritis Outcome Score (KOOS) (only adults), measured maximum isokinetic knee strength (60°/s) and peak vertical jump displacement (PVJD), with calculated knee strength balance, Hamstring/Quadriceps (H/Q) ratio and peak rate of force development (PRFD).nnnRESULTSnAdults with GJH had lower knee function (KOOS: pain, p=0.001; symptoms, p=0.001; Activities of Daily Living, p=0.001; Sport/Recreation, p=0.003; knee-related quality of life, p<0.001), and H/Q ratio (0.46 vs. 0.54, p=0.046) than adults with NGJH, regardless of age and knee pain. Both GJH groups had normal physical fitness, isokinetic knee strength, and (only children) H/Q ratio.nnnCONCLUSIONSnChildren at 10 years with GJH have normal, but adults with GJH have impaired knee function. To track the risk of developing impaired knee function, children with GJH must be followed longitudinally. Meanwhile, attention to knee function may be given to children with GJH who have parents presenting GJH.

Gait pattern in 9-11-year-old children with generalized joint hypermobility compared with controls; a cross-sectional study

BackgroundTo study differences in gait patterns in 10-year-old children with Generalized Joint Hypermobility (GJH) and with no GJH (NGJH).MethodsA total of 37 children participated (19 GJH, 18 NGJH, mean age 10.2 (SD 0.5) years). Inclusion criteria for GJH were a Beighton score of ≥5, with at least one hypermobile knee joint; for NGJH a Beighton score of ≤4, and no hypermobile knees and for both groups no knee pain during the previous week. All children were recorded by five video cameras, while they walked across three force platforms. Net joint moments were calculated in 3D by inverse dynamics and peak values provided input to statistical analyses.ResultsIn the frontal plane, children with GJH had a significantly lower peak knee abductor moment and peak hip abductor moment. In the sagittal plane, the peak knee flexor moment and the peak hip extensor moment were significantly lower in the GJH group although the absolute difference was small.ConclusionsThe walking pattern was the same for children with GJH and for healthy children, as there were no differences in kinematics, but it was, however, performed with different kinetics. Children with GJH walked with lower ankle, knee and hip joint moments compared to children with NGJH. However, the clinical importance of these differences during normal gait is unknown. To obtain this knowledge, children with GJH must be followed longitudinally.Trial registrationThe study was approved by the Committee on Biomedical Research Ethics for Copenhagen and Frederiksberg, Denmark (jnr. KF01-2006-178).

Impaired postural control in children with developmental coordination disorder is related to less efficient central as well as peripheral control

BACKGROUNDnDevelopmental coordination disorder (DCD) is a neurodevelopmental impairment that affects approximately 6% of children in primary school age. Children with DCD are characterized by impaired postural control. It has yet to be determined what effect peripheral and central neuromuscular control has on their balance control.nnnOBJECTIVEnThe aim of this study was to investigate the underlying mechanisms to impaired postural control in children with DCD using the rambling-trembling decomposition of the center of pressure (CoP).nnnMETHODnNine children with DCD (9.0±0.5years, 7 boys, 2 girls) and 10 age- and gender-matched typically developing children (TD) with normal motor proficiency (9.1±0.4years, 7 boys and 3 girls) performed 3×30s bipedal standing on a force plate in six sensory conditions following the sensory organization procedure. Sway length was measured and rambling-trembling decomposition of CoP was calculated in medio-lateral (ML) and anterior-posterior (AP) direction.nnnRESULTSnBoth rambling and trembling were larger for the children with DCD in AP (p=0.031; p=0.050) and ML direction (p=0.025; p=0.007), respectively. ML rambling trajectories did not differ in any conditions with fixed support surface. In ML direction children with DCD had a lower relative contribution of rambling to total sway (p=0.013).nnnCONCLUSIONnThis study showed that impaired postural control in children with DCD is associated with less efficient supraspinal control represented by increased rambling, but also by reduced spinal feedback control or peripheral control manifested as increased trembling.

Motor intensive anti-gravity training improves performance in dynamic balance related tasks in persons with Parkinson's disease

Recent studies indicate that the effect of training on motor performance in persons with Parkinsons disease (PDP) is dependent on motor intensity. However, training of high motor intensity can be hard to apply in PDP due to e.g. bradykinesia, rigidity, tremor and postural instability. Therefore, the aim was to study the effect of motor intensive training performed in a safe anti-gravity environment using lower-body positive pressure (LBPP) technology on performance during dynamic balance related tasks. Thirteen male PDP went through an 8-week control period followed by 8 weeks of motor intensive antigravity training. Seventeen healthy males constituted a control group (CON). Performance during a five repetition sit-to-stand test (STS; sagittal plane) and a dynamic postural balance test (DPB; transversal plane) was evaluated. Effect measures were completion time, functional rates of force development, directional changes and force variance. STS completion time improved by 24% to the level of CON which was explained by shorter sitting-time and standing-time and larger numeric rate of force change during lowering to the chair, indicating faster vertical directional change and improved relaxation. DPB completion time tended to improve and was accompanied by improvements of functional medial and lateral rates of force development and higher vertical force variance during DPB. Our results suggest that the performance improvements may relate to improved inter-limb coordination. It is concluded that 8 weeks of motor intensive training in a safe LBPP environment improved performance during dynamic balance related tasks in PDP.

Parkinson's disease and transcranial pulsed electromagnetic fields: A randomized clinical trial

New potential nonpharmacological and noninvasive treatments for PD are seldom investigated and deserve attention. Pulsed electromagnetic fields could allay PD neurodegeneration through neurogenesis and neuroprotection via up regulation of brain-derived neurotrophic factor, neurite outgrowth, and neural anti-inflammatory effects. In this study, the treatment modality transcranial pulsed electromagnetic fields (T-PEMF) was assessed for the effect on PD symptoms using the UPDRS. The study was designed as a double-blinded, randomized controlled trial with one group receiving active T-PEMF treatment and the other receiving sham T-PEMF treatment. T-PEMF was applied 30 minutes once daily for 8 consecutive weeks. Electric pulses were applied to the brain tissue through 7 electromagnetic coils distributed over the frontal-, parietal-, temporal-, and occipital lobes. Squared bipolar pulses of 650 mV and 2.25 ms duration at a frequency of 50 Hz generated pulsed electromagnetic fields of 5 to 8 mT 1 cm from the coils. T-PEMF differs from transcranial magnetic stimulation by not inducing an action potential in excitable cells. UPDRS data from 92 participants with idiopathic PD were analyzed. All participants were in stable and optimal medical treatment regarding PD before inclusion. The participants in the active group had a mean age of 66.7 years, mean Hoehn & Yahr score of 2.4, and mean disease duration of 6.3 years. Those in the placebo group had a mean age of 64.9 years, mean Hoehn & Yahr score of 2.2, and mean disease duration of 5.1 years. Treatment compliance was 97.9%. The active group and the placebo group improved in UPDRS total score and part scores I to IV from baseline to endpoint with no between-group difference. The placebo group improved in subscores IVa and IVc, but not in subscore IVb; in the active group, no improvement was seen for subscores IVa-c (Table 1). The development of dyskinesias in the active group could be a result of the upregulation of dopamine levels resulting from T-PEMF treatment combined with well-medicated participants. For the differences between groups in subscore IVc, no obvious explanations were found. However, comparing subscores can lead to false positive conclusions. Moreover, the UPDRS is a subjective and somewhat insensitive scale that may not collect discrete changes in symptoms. Thus, the present results do not *Corresponding author: Dr. Bo Mohr Morberg, Department of Neurology, Odense University Hospital, Sdr. Boulevard 29, 5000 Odense C, Denmark; bo.mohr.morberg@rsyd.dk

Association Between Gross-Motor and Executive Function Depends on Age and Motor Task Complexity

ABSTRACT The objective was to examine associations between motor and executive function across the adult lifespan and to investigate the role of motor complexity in these associations. Young, middle-aged and older adults (n = 82; 19–83y) performed two gross-motor tasks with different levels of complexity and a Stroop-like computer task. Performance was decreased in older adults. The association between motor and cognitive performance was significant for older adults in the complex motor task (p = 0.03, rs = −0.41), whereas no significant associations were found for young or middle-aged groups, suggesting that the link between gross-motor and executive function emerges with age and depends on motor complexity.

Local dynamic stability during treadmill walking can detect children with developmental coordination disorder

OBJECTIVEnDevelopmental coordination disorder (DCD) is an innate impairment of motor coordination that affects basic locomotion and balance. This study investigated local dynamic stability of trunk accelerations during treadmill walking as an objective evaluation of gait stability and the sensitivity and specificity of this measure to discriminate children with DCD from typically developing children.nnnMETHODnEight children with DCD and ten age- and gender-matched typically developing children (TD) walked four minutes on a treadmill. Trunk accelerations in vertical, medio-lateral and anterior-posterior directions were recorded with a sternum mounted accelerometer at 256Hz. Short term local dynamic stability (λs), root mean square (RMS) and relative root mean square (RMSR) were calculated from measures of orthogonal trunk accelerations. Receiver operating characteristic curve (ROC) analysis was performed to discriminate between groups based on short term local dynamic stability.nnnRESULTSnλs was significantly greater in children with DCD in the main movement direction (AP) (DCD: 1.69±0.17 λs; TD:1.41±0.17 λs; p=0.005), indicating reduced local dynamic stability. RMS and RMSR accelerations showed no difference between children with DCD and TD children in any direction. The ROC analysis of λs in separate directions and in two dimensions showed an excellent accuracy of discriminating between children with DCD and TD children. Anterior-posterior direction in combination with medio-lateral or vertical showed best performance with an area under the curve (AUC) of 0.91.nnnCONCLUSIONnWe have shown that children with developmental coordination disorder have general reduced local dynamic stability and that the short term Lyapunov exponent has good power of discrimination between DCD and TD.

Effects of transcranial pulsed electromagnetic field stimulation on quality of life in Parkinson's disease

Pulsed electromagnetic fields induce a protective and anti‐inflammatory effect in the nervous system primarily due to growth factor upregulation that possibly abates neurodegeneration in Parkinsons disease (PD). This study investigated treatment effects of transcranial pulsed electromagnetic fields (T‐PEMFs) on quality of life in PD and the feasibility and safety of this treatment.

Effects of Long-Term Treatment with T-PEMF on Forearm Muscle Activation and Motor Function in Parkinson's Disease

Bipolar pulsed electromagnetic stimulation applied to the brain (T-PEMF) is a non-pharmacological treatment which has been shown to stimulate nerve growth, attenuate nerve abnormalities, and improve microcirculation. We report on a 62-year-old, medically well-treated man with idiopathic Parkinson’s disease. He was treated with T-PEMF, 30 min per day for three 8-week periods separated by two 1-week breaks. The disease made his handwriting impossible to read mainly due to small letters and lack of fluency. Forearm EMG measured during standardized conditions showed an involuntary spiky EMG pattern with regular burst activity (on his left side) at baseline. The intervention normalized the handwriting and forearm EMG. The UPDRS-motor score decreased from 25 to 17, and UPDRS-II-handwriting decreased from a pre-intervention value of 3 to 0 after the intervention. Finally, the patient reported improved fine motor function, less muscle stiffness, less muscle cramps and tingling, and less fatigue during the day in response to the T-PEMF treatment. The improved handwriting lasted for approximately 3 months after the treatment. Our results should be considered as preliminary, and large-scale, controlled studies are recommended to elucidate the therapeutic potential of long-term treatment with T-PEMF.

Alterations in neuromuscular function in girls with generalized joint hypermobility

BackgroundGeneralized Joint Hypermobility (GJH) is associated with increased risk of musculoskeletal joint pain. We investigated neuromuscular performance and muscle activation strategy.MethodsGirls with GJH and non-GJH (NGJH) performed isometric knee flexions (90°,110°,130°), and extensions (90°) at 20xa0% Maximum Voluntary Contraction, and explosive isometric knee flexions while sitting. EMG was recorded from knee flexor and extensor muscles.ResultsEarly rate of torque development was 53xa0% faster for GJH. Reduced hamstring muscle activation in girls with GJH was found while knee extensor and calf muscle activation did not differ between groups. Flexion-extension and medial-lateral co-activation ratio during flexions were higher for girls with GJH than NGJH girls.ConclusionsGirls with GJH had higher capacity to rapidly generate force than NGJH girls which may reflect motor adaptation to compensate for hypermobility. Higher medial muscle activation indicated higher levels of medial knee joint compression in girls with GJH. Increased flexion-extension co-activation ratios in GJH were explained by decreased agonist drive to the hamstrings.