Antonio Pinti

The role of muscle strength & activation patterns in patellofemoral pain

BACKGROUND To investigate the extent to which quadriceps muscle activation and strength are responsible for patellofemoral pain. METHODS A pain on-off switch system synchronized with a force transducer and surface electromyography was utilized on 32 volunteer patellofemoral pain patients during maximal isometric and squat exercises. FINDINGS There were 26 patients out of the 32 tested who complained of pain during the squat or isometric test, of these 20 subjects presented a significant advantage for the vastus lateralis compared to the vastus medialis obliquis activation and 12 patients had decreased quadriceps strength of the symptomatic compared to the non symptomatic leg. All patients who demonstrated weak vastus medialis obliquis activation during the isometric exercise possessed the same symptoms during the squat. On the other hand, 9 patients who showed diminished vastus medialis obliquis activation during the squat displayed equal activation between the vastus medialis obliquis and the vastus lateralis during the isometric task. With regard to the timing for the onset of muscle activation, there were only 4 patients who had a difference (P=0.03) between the symptomatic (0.042 s) and non-symptomatic legs (0.011 s). INTERPRETATION Causes for patellofemoral pain vary and are not necessarily a result of quadriceps strength deficit or vastus medialis obliquis activation weakness. Patellofemoral pain patients who possess lower vastus medialis obliquis activation compared to the vastus lateralis do not necessarily have quadriceps weakness while patients presenting with quadriceps strength deficits do not always have an imbalance between vastus medialis obliquis and vastus lateralis activation.

Regional variations in human patellar trabecular architecture and the structure of the quadriceps enthesis: a cadaveric study

We investigated whether there were regional differences in the quadriceps enthesis and the patella bone structure that could suggest unequal force transmission to the patella. Quadriceps tendon enthesis was removed by cutting the patellae transversally in the middle and the quadriceps tendon approximately 1 cm from the bone. Tissues were post‐fixed, decalcified, dehydrated through and embedded in paraffin wax. Serial longitudinal sections were cut, mounted on glass slides at 1‐mm intervals and slides were stained. Trabecular architecture was analysed from digital images taken from the histological slides, and regional differences at the enthesis in the thickness of the uncalcified fibrocartilage and the cortical zone of calcified tissue (calcified cartilage and lamellar bone) were evaluated. At the quadriceps enthesis, the thickness of the cortical zone of calcified tissue was significantly greater in the central part of the enthesis than medially and laterally. The trabeculae were thicker in the central and lateral parts compared with the medial region. Similarly, the zone of uncalcified fibrocartilage was thicker laterally and centrally than medially. Bone structure and the thickness of uncalcified fibrocartilage presented a similarity between the centre and the lateral parts; however, the medial side was different. We suggest that the mechanical stress at the proximal quadriceps tendon enthesis is higher laterally and centrally compared with medially. This could induce a lateral patellar translation, which is potentially a risk factor for knee osteoarthritis.

Physical Performance Variables and Bone Mineral Density in a Group of Young Overweight and Obese Men

The aim of this study was to explore the relationships between performances obtained in different physical tests and bone parameters (bone mineral density [BMD], bone mineral content, hip geometry indices, and trabecular bone score [TBS]) in a group of young Lebanese overweight and obese adult men. Fifty-two overweight and/or obese (body mass index > 25 kg/m2) young men whose ages range from 18 to 35 yr participated in this study. Weight and height were measured, and body mass index was calculated. Body composition, BMD, cross-sectional area and section modulus (Z) of the femoral neck (FN), and TBS were measured by dual-energy X-ray absorptiometry. Maximum oxygen consumption (VO2 max, in liter per minute) was determined by direct measurement while exercising on a medical treadmill. One-repetition-maximum half-squat and maximum power (P max) of the lower limbs were measured using validated exercises. Lean mass was a positive determinant of whole-body bone mineral content (r = 0.71, p < 0.001), FN cross-sectional area (r = 0.51, p < 0.001), and FN Z (r = 0.58, p < 0.001). VO2 max (in liter per minute) was a positive determinant of whole-body BMD (r = 0.47, p < 0.001), total hip BMD (r = 0.43, p < 0.01), and FN BMD (r = 0.42, p < 0.01). VO2 max (in milliliter per minute per kilogram) was a positive determinant of TBS (r = 0.30, p < 0.05). One repetition maximum was a positive determinant of L1-L4 BMD (r = 0.33, p < 0.05). This study suggests that VO2 max (in liter per minute) is a positive determinant of BMD, and VO2 max (in milliliter per minute per kilogram) is a positive determinant of TBS in overweight and obese men.

Decreased Composite Indices of Femoral Neck Strength in Young Obese Men

The aim of the current study was to compare compression strength index (CSI), bending strength index (BSI) and impact strength index (ISI) among obese, overweight and normal-weight young women. 117 young women (20 obese, 36 overweight and 61 normal-weight) whose ages range from 18 to 35 years participated in this study. Body composition and BMD were evaluated by dual-energy X-ray absorptiometry (DXA). CSI, BSI and ISI values were significantly lower in obese and overweight women compared to normal-weight women (p < 0.001). In the whole population (n = 117), body mass index (BMI) was negatively correlated to CSI (r = −0.66; p < 0.001), BSI (r = −0.56; p < 0.001) and ISI (r = −0.54; p < 0.001). This study suggests that obesity is associated with lower CSI, BSI and ISI values in young women.

Association between individual quadriceps muscle volume/enthesis and patello femoral joint cartilage morphology.

IntroductionThe aim of this study was to determine the association between individual quadriceps muscle volumes and the quadriceps enthesis structures and cartilage morphology at the patellofemoral joint (PFJ).MethodsWe studied 12 cadavers (age 75 ± 5 years). For both legs, individual quadriceps muscles (vastus lateralis (VL), rectus femoris (RF), vastus intermedialis (VI) and vastus medialis (VM)) were dissected and their volumes measured. Cartilage areas at the PFJ were classified using the International Cartilage Repair Society (ICRS) score. Histological sections were evaluated at the quadriceps tendon enthesis (laterally, centrally and medially). Several variables were calculated on the binary images based on two-dimensional analysis. These were apparent bone area (BA) and apparent trabecular thickness (TH). A Spearman rank test was used to determine the strength of correlation between individual quadriceps muscles volume, the structure of the quadriceps tendon enthesis and the ICRS score.ResultsThe thickness of calcified fibrocartilage tissue was significantly greater in the central part of the enthesis than both medially (P = 0.03) and laterally (P = 0.04). Uncalcified fibrocartilage was significantly thicker laterally (P = 0.04) and centrally (P = 0.02) than medially. Muscle volume was highest (P <0.05) for the VL, followed by the VI, VM and RF. There was no association between total and individual muscle volumes and ICRS or BA. However, there was a strong positive correlation (r = 0.81) between the VL/VM volume ratio and BA ratio (bone volume at the lateral part divided by bone volume at the medial part). There was a moderate positive correlation between VL/VM and ICRS (r = 0.65) and between ICRS and BA ratio (lateral/medial; r = 0.74).ConclusionsIndividual and total quadriceps volumes were not correlated with cartilage loss at the PFJ or fibrocartilage thickness. However, both VL/VM and BA ratio (lateral/medial) were positively correlated with ICRS scoring and therefore could be a tool for predicting degree of PFJ osteoarthritis severity.

An Automatic FCM-Based Method for Tissue Classification Application to MRI of Thigh

Fuzzy C-means (FCM) has been frequently used to image segmentation in order to separate objects. The most used segmentation attribute is grey level of pixels. Nevertheless, this method can not identify complex image objects because grey level can not take into account all visual information. This paper describes a modified FCM method for tissue classification using retrospective operation of partition tree with expert knowledge. This method is applied to 26 MRI (Magnetic Resonance Imaging) images of thigh for localizing four main anatomical tissues: muscle, adipose tissue, cortical bone, and spongy bone. A test dataset of 6500 representative points has been created by an expert. Using our method, we obtain a classification rate of 95.73% in the test dataset, which largely improved the classification results obtained from existing methods.

Trabecular Bone Score in Overweight and Normal-Weight Young Women

The aim of this study was to compare Trabecular Bone Score (TBS) in overweight and normal-weight young women. This study included 14 overweight (BMI > 25 kg/m2) and 42 normal-weight (BMI < 25 kg/m2) young Lebanese women whose ages range from 18 to 32 years. Body composition, Bone Mineral Content (BMC), Bone Mineral Density (BMD), and lumbar spine (L1–L4) TBS were assessed by dual-energy X-ray asborptiometry (DXA). The DXA measurements were completed for the whole body (WB), the lumbar spine (L1–L4), the total hip (TH) and the femoral neck (FN). Physical activity, daily calcium intake, daily protein intake and sleep quality index were evaluated using validated questionnaires. Maximal oxygen consumption (VO2 max in l/mn) was measured whilst exercising on a bicycle ergometer using a specialized device. Weight, height, BMI, lean mass, fat mass, WB BMC, WB BMD, TH BMD and FN BMD were significantly higher in overweight women compared to normal-weight women. Trabecular Bone Score (TBS) was not significantly different between the two groups (overweight and normal-weight). In the whole population (n = 56), weight, height, BMI, lean mass and fat mass were positively correlated to BMC and BMD values but not to TBS values. VO2 max (l/mn) was positively correlated to BMC, BMD and TBS (p < 0.05). This study suggests that being overweight is not associated with higher trabecular bone score values in young women.

Sarcopenia and Hip Structure Analysis Variables in a Group of Lebanese Postmenopausal Women

The aim of the present study was to compare hip structural analysis variables in postmenopausal women with sarcopenia and postmenopausal women with normal skeletal muscle mass index. This study included 8 postmenopausal women (aged between 65 and 84 years) with sarcopenia and 60 age-matched controls (with normal skeletal muscle mass index (SMI)). Body composition and bone mineral density (BMD) were assessed by dual-energy X-ray absorptiometry (DXA). Weight, lean mass, Body mass index, femoral neck cross-sectional area (FN CSA), FN section modulus (Z), FN cross sectional moment of inertia (CSMI), intertrochanteric (IT) CSA, IT Z, IT CSMI, IT cortical thickness (CT), femoral shaft (FS) CSA, FS Z and FS CSMI were significantly higher (p < 0.05) in women with normal SMI compared to women with sarcopenia. In the whole population, SMI was positively correlated to IT CSA, IT Z, IT CSMI, IT CT, FS CSA, FS Z, FS CSMI, FS CT but negatively correlated to IT buckling ratio (BR) and FS BR. The present suggests that sarcopenia negatively affects hip bone strength indices in postmenopausal women.

Maximal Oxygen Consumption and Composite Indices of Femoral Neck Strength in a Group of Young Women

The aim of this study was to explore the relationship between maximal oxygen consumption (VO2 max; mL/mn/kg) and composite indices of femoral neck strength in a group of young women. 41 young women whose ages ranged from 18 to 35 years participated in the present study. Femoral neck bone mineral density was measured by DXA. Composite indices of femoral neck strength (CSI, BSI and ISI) were calculated. VO2 max (mL/mn/kg) of the participants was measured using a Cosmed Fitmate pro device (version 2.20) while exercising on a bicycle ergometer (Siemens-Elema RE 820; Rodby Elektronik AB, Enhorna, Sweden). VO2 max (mL/mn/kg) was positively correlated to CSI (r = 0.52; p < 0.001) and ISI (r = 0.45; p < 0.01). The positive associations between VO2 max (mL/mn/kg) and these two indices (CSI and ISI) remained significant after controlling for body mass index using multiple linear regression models.

An Online Viewer of FHR Signal for Research, E-Learning and Tele-Medicine

This paper presents a web viewer of Fetal Heart Rate (FHR) signals developed on HTML5/JavaScript. It provides an easy solution to remotely consult an FHR signal on a web browser without installing any specific software and it can be used either on a computer or on mobile device. There are three major applications of this tool. First, it is used to build up our FHR database used for research on signal processing and analysis. Secondly, it is used on our E-learning website e.RCF in order to train midwives and obstetricians to interpret FHR signals. At last, it could be used on telemedicine either on tele-monitoring to remotely check the fetal welfare, or on tele-expertise to enable practitioners to ask for specialists’ opinion. This viewer is designed to correspond to practitioners’ habits while including tools to ease the interpretation the FHR signal.