Muscle activation, strength, and volume in people with patellofemoral osteoarthritis: a systematic review and meta-analysis.

OBJECTIVE: This systematic review investigated whether people with patellofemoral osteoarthritis (PFOA) have muscle strength, volume, and activation around the hip and knee that is different from asymptomatic controls. METHODS: Searches were carried out in five electronic databases, with terms related to PFOA, including muscle strength, volume and activation. Only studies with at least one group with symptomatic PFOA and one asymptomatic group were included. The methodological quality of the studies was assessed using the Downs and Black checklist. Certainty of evidence was assessed using the GRADE methodology. Using the random effects model, a meta-analysis was performed when there were at least two studies reporting the same domain. RESULTS: Eight studies (250 participants) met the inclusion criteria. Subjects with PFOA had weaker hip abduction (SMD -0.96; 95%CI = -1.34 to -0.57), hip external rotation (-0.55;-1.07 to -0.03), hip extension (-0.72;-1.16 to -0.28), and knee extension (-0.97;-1.41 to -0.53) when compared to asymptomatic controls. People with PFOA also presented with smaller volumes of the gluteus medius, gluteus minimus, tensor fascia lata, vastus medialis (VM), vastus lateralis (VL) and rectus femoris when compared to asymptomatic controls. Also, people with PFOA presented with changes in muscle activation for the VL, VM and gluteus maximus (GMax) when compared to asymptomatic controls. CONCLUSION: People with PFOA present with lower strength and volume of the hip and quadriceps muscles and altered muscle activation of the VM, VL and GMax during ascending and descending stairs when compared to asymptomatic controls. However, the certainty of these findings are very low. TRIAL REGISTRATION NUMBER: PROSPERO systematic review protocol (ID = CRD42020197776).

The Effects of Forefoot Striking, Increasing Step Rate, and Forward Trunk Lean Running on Trunk and Lower Limb Kinematics and Comfort.

This study aimed to compare the immediate effects of 3 running technique modifications on the ankle, knee, hip and trunk kinematics and on the perceived comfort in healthy runners. The modifications were: forefoot striking pattern (FFOOT); increasing 10% of step rate (10% SR); and increasing forward trunk lean (FTL). 31 healthy runners participated. 3-dimensional lower limb and trunk kinematics were quantified while performing each condition on a treadmill. At initial contact, the FFOOT showed an increase in plantar flexion and knee external rotation, and reduction in knee flexion and adduction. During the stance phase, this condition showed greater peak knee external rotation and less mean and peak dorsiflexion and knee flexion. The 10% SR resulted in less hip flexion at initial contact. During the stance phase this technique showed less mean and peak knee flexion, peak reduction for dorsiflexion, knee abduction, hip flexion and hip adduction. At initial contact and during the stance phase, the FTL caused greater knee adduction and hip flexion. The usual running was the most comfortable technique. The techniques showed different lower limb kinematic modifications; which could potentially reduce knee injury risk. This knowledge is clinically relevant as it can be used to better prescribe techniques in prevention and rehabilitation programs.

Hip and knee kinematics are associated with pain and self-reported functional status in males and females with patellofemoral pain.

Altered hip and knee kinematics in the frontal and transverse planes may increase patellofemoral joint stress and contribute to the development of patellofemoral pain. The purpose of this cross-sectional study was to evaluate the association among hip and knee kinematics, pain, and self-reported functional status in males and females with patellofemoral pain. 20 males and 20 females with patellofemoral pain participated in this study. 3-dimensional hip and knee kinematics were quantified while performing a step-down task. A visual analogue scale was used to evaluate usual knee pain. The anterior knee pain scale was used to evaluate the knee functional score. For both groups combined, greater usual pain was associated with greater peak hip adduction, hip internal rotation and knee abduction (r=0.54-0.57, P<0.001). Also, modest to low correlations (r=-0.48 to - 0.37, P=0.03-0.08) were found among hip and knee kinematics and functional score. Stepwise regression revealed that peak hip internal rotation and hip adduction were significant predictors of pain, while peak hip adduction was the only predictor of function. Greater hip adduction, hip internal rotation and knee abduction are associated with higher levels of pain and reduced function in males and females with patellofemoral pain.

Antenatal post-hemorrhagic ventriculomegaly: a prospective follow-up study.

OBJECTIVE: The aim of this study was to evaluate the presence and the severity of neurological and cognitive impairment at 2 years of age in 16 infants (9 term born, 7 preterm of mean gestation 33.6 weeks) with cerebral ventriculomegaly of antenatal onset associated with intraventricular haemorrhage. METHODS: Ventricular dilatation, with or without associated lesions, was, with one exception, not identified on the antenatal routine scan at approximately 22 weeks but was obvious on the scans performed between weeks 27 and 33. In 8 of the 16 cases there were signs of parenchymal involvement or of abnormalities of the corpus callosum or cerebellum. In all patients the diagnosis of antenatal IVH was confirmed by early neonatal imaging. Outcome was measured using the Hammersmith infant neurological examination and the Griffiths developmental scales at 2 years. RESULTS AND CONCLUSIONS: At 2 years, 8 infants had normal motor outcome and 8 had cerebral palsy. The presence and severity of cerebral palsy or neurodevelopmental delay was not always related to the magnitude or symmetry of the ventricular dilatation per se. The presence of associated lesions was a negative prognostic marker. The early development of epilepsy was also associated with an abnormal outcome.

Analise do torque isometrico e da atividade elétrica apos lesão muscular induzida por exercício excentrico em humanos / Analysis of isometrci torque and of the electrical activity after induced muscle damage by eccentric exercise human

Este estudo avaliou e relacionou as alteracoes funcionais domusculo quadriceps femoral apos lesao induzida pelo exercicio excentrico. O torque isometrico maximo medio desse musculo e a eletromiografia de superficie (raiz quadrada da media dos quadrados, root meam square - RMS; frequencia mediana -FM) dos musculos vasto medial obliquo(VMO) e vasto lateral(VL) foram avaliados antes, imediatamente apos e durante os 7 dias apos o exercicio excentrico. As imagens de ressonancia magnetica nuclearRMN) de tres voluntarias foram usadas para evidenciar a presenca de lesao muscular. Nove mulheres (21,7+-1,48 anos), sedentarias e saudaveis, foram avaliadas. A lesao foi induzida por meio de contracoes isocineticas excentricas. O torque isometrico maximo medio e a atividade eletrica foram mensurados por meio da contracao isometrica maxima com o joelho a 90 graus de flexao. O torque isometrico maximo medio diminiu imediatamente apos o exercicio excentrico (p<0,01), com recuperacao gradual na primeira semana. O RMS do musculo VL diminuiu imediatamente apos o exercicio excentrico (p<0,05). Por outro lado, somente o musculo VMO ocorreu aumento na FM imediatamente apos o exercicio excentrico (p<0,01). Correlacao significativa foi observada entre o torque isometrico maximo medio e a FM do musculo VMO entre o 1o. e 7o. dia apos o exercicio (r=0,32, p<0,05). Extensas areas de lesao no musculo quadriceps femoral foram identificadas pela RMN. Em conclusao, o exercicio excentrico diminuiu o torque isometrico maximo medio e alterou o sinal eletromiografico, os quais se recuperaram gradualmente na primeira semana, apesar da presenca de lesao muscular

Functional changes of human quadriceps muscle injured by eccentric exercise.

The present study evaluated functional changes of quadriceps muscle after injury induced by eccentric exercise. Maximal isometric torque of quadriceps and the surface electromyography (root mean square, RMS, and median frequency, MDF) of the vastus medialis oblique (VMO) and vastus lateralis (VL) muscles were examined before, immediately after and during the first 7 days after injury. Serum creatine kinase (CK) levels and magnetic resonance imaging (MRI) were used to identify muscle injury. The subject was used as her own control and percent refers to pre-injury data. Experiments were carried out with a sedentary 23-year-old female. Injury was induced by 4 bouts of 15 maximal isokinetic eccentric contractions (angular velocity of 5 /s; range of motion from 40 to 110 of knee flexion). The isometric torque of the quadriceps (knee at 90 flexion) decreased 52% immediately after eccentric exercise and recovered on the 5th day. The highest reduction of RMS occurred on the 2nd day after injury in both VL (63%) and VMO (66%) and only VL recovered to the pre-injury level on the 7th day. Immediately after injury, the MDF decreased by 5 and 3% (VMO and VL, respectively) and recovered one day later. Serum CK levels increased by 109% on the 2nd day and were still increased by 32% on the 7th day. MRI showed large areas of injury especially in the deep region of quadriceps. In conclusion, eccentric exercise decreased the isometric torque and electromyographic signals of quadriceps muscle, which were recovered in one week, despite the muscle regeneration signals.

Functional changes of human quadriceps muscle injured by eccentric exercise

The present study evaluated functional changes of quadriceps muscle after injury induced by eccentric exercise. Maximal isometric torque of quadriceps and the surface electromyography (root mean square, RMS, and median frequency, MDF) of the vastus medialis oblique (VMO) and vastus lateralis (VL) muscles were examined before, immediately after and during the first 7 days after injury. Serum creatine kinase (CK) levels and magnetic resonance imaging (MRI) were used to identify muscle injury. The subject was used as her own control and percent refers to pre-injury data. Experiments were carried out with a sedentary 23-year-old female. Injury was induced by 4 bouts of 15 maximal isokinetic eccentric contractions (angular velocity of 5º/s; range of motion from 40º to 110º of knee flexion). The isometric torque of the quadriceps (knee at 90º flexion) decreased 52 percent immediately after eccentric exercise and recovered on the 5th day. The highest reduction of RMS occurred on the 2nd day after injury in both VL (63 percent) and VMO (66 percent) and only VL recovered to the pre-injury level on the 7th day. Immediately after injury, the MDF decreased by 5 and 3 percent (VMO and VL, respectively) and recovered one day later. Serum CK levels increased by 109 percent on the 2nd day and were still increased by 32 percent on the 7th day. MRI showed large areas of injury especially in the deep region of quadriceps. In conclusion, eccentric exercise decreased the isometric torque and electromyographic signals of quadriceps muscle, which were recovered in one week, despite the muscle regeneration signals

[Thoracic imaging in adolescence: news and perspectives]. / L'imaging toracico in età pediatrica adolescenziale: attualità e prospettive.

Technological advances modified actual trends in pediatric imaging. Up 25 years ago thoracic X-ray was the only resource in pediatric radiology. The introduction of CT, digital radiography, sonography and magnetic resonance and then of psitron emission tomography, led to a new dimension in thoracic pediatric imaging. In the future, new technological perspectives will make the functional study of the lung ventilation possible with techniques such as the 3-He hyperpolarized.

Some parameters of descending inhibition during colonic propulsion.

Isolated segments of rabbit distal colon were stimulated by distension of intraluminal balloons, with the aim of investigating the electrophysiological pattern of descending inhibition (DI) during the peristaltic reflex. Incidence, duration, and latency of DI were studied by varying the parameters of stimulation. A linear correlation was found between stimulus duration and DI duration for stimuli up to 10 s long. DI duration increased with the distance of the recording site from the stimulus up to 3 cm. A more complex relation was found between balloon volume and DI duration. Propagation velocity decreased with the distance from the stimulus. The relation between ascending excitation and DI was also studied: ascending excitation could always be suppressed by DI. DI was examined after addition of anticholinergics, ganglionic blocking agents, and tetrodotoxin to the organ bath. The results show that DI parameters are partially related to the stimulus characteristics and that propagation of DI is neurally mediated through nonadrenergic inhibitory nerves.

[Post-traumatic pneumomediastinum (not associated with pleuro-mediastinical organ's lesion). Two cases (author's transl)]. / Pneumomédiastin post-traumatique (non associé à des lésions des organes pleuro-médiastinaux). Deux observations.

The authors of this article describe two cases of post-traumatic pneumomediastinum, without pneumothorax and oesophageal or bronchial mucosal lesions. Both cases had a benign evolution. General considerations are discussed and the authors concluded that when pneumomediastinum is not associated with lesions of mediastinical organs no surgical treatment is usually required.