A BIOMECHANICAL STUDY SHOULDER PAIN IN ELITE GYMNASTS

Introduction: Shoulder problems are common in overhead sports like baseball, basketball and volleyball. Although gymnastics consists of overhead activities, there are few studies of shoulder problems in this sport. During 1992-1995 we treated five young competitive gymnasts for shoulder pain. Arthroscopy revealed that all suffered from SLAP-lesions or other labral pathologies although they had never dislocated their shoulders. Since four of these athletes stated that they first became aware of acute shoulder pain during ring exercises in suspension, we decided to make an EMG-study of the shoulder musculature during exercises on the parallel bars and rings. Methods: Three elite gymnasts were investigated with telemetric surface EMG of the pect.maj., deltoid, biceps, triceps, trapezius and lat.dorsi. The gymnasts performed the standard bar and ring program. Results: During the ring exercises in suspension there was a ‘critical phase’ during which muscle activity around the shoulder was very low, leading to great articular stresses at the end of the ‘giant swing’, when their shoulders were suddenly exposed to a load of several times their body weight. EMG of biceps brachii was 67 µV just before the end of the giant swing and increased to 698µV. A similar tenfold increase was found in the other muscles as well. This probably explains the occurrence the SLAP lesions. A very strong pull in the long biceps tendon (before the muscle contracts) could tear loose the superior labrum and cause this socalled SLAP-lesion. Modifications of the rings or the ring exercises might decrease the occurrence of SLAP-lesions. Conclusion: Telemetric EMG analysis of the shoulder musculature during ring exercises provided an explanation for the occurrence of SLAP-lesions in gymnasts

Surgical treatment of a rare isolated bilateral agenesis of anterior and posterior cruciate ligaments.

The isolated bilateral agenesis of both cruciate ligaments is a rare congenital disorder. A 17-year-old male came to our attention due to an alteration in gait pattern, pain, and tendency to walk on the forefoot with his knee flexed. The patient did not recall previous injuries. Upon physical examination anterior and posterior chronic instability were observed. Radiographic examination of both knees showed hypoplasia of the tibial eminence, a hypoplastic lateral femoral condyle, and a narrow intercondylar notch. MRI brought to light a bilateral agenesis of both posterior cruciate ligaments. Arthroscopic evaluation confirmed bilateral isolated agenesis of both cruciate ligaments. We recommended a rehabilitation program to prepare the patient for the arthroscopic construction of both cruciate ligaments

IS PRINCIPAL COMPONENT ANALYSIS MORE EFFICIENT TO DETECT DIFFERENCES ON BIOMECHANICAL VARIABLES BETWEEN GROUPS?

The biomechanical analysis investigates variables such as angles, inter-segmental forces and moments at the joints. When the relevant parameters (e.g., range of motion, peak values) are selected a priori from these variables, they could not perfectly represent the information content of the original dataset. Therefore, in this study we want to validate the efficacy of the Principal Component Analysis (PCA) in overcoming the limitations of the a priori selection of the parameters. An application study is reported; the lower-limb joint mechanics between patients operated with two different surgical techniques for a total hip arthroplasty are analyzed with both the traditional analysis and the PCA. The findings from the two methods converged, but the PCA identified new sources of variability not previously detected

A VIRTUAL CRANKSHAFT THIGH MODEL TO ESTIMATE TIBIAL-FEMORAL TRANSVERSE PLANE KINEMATICS

Sports injuries often require a thorough evaluation of the knee that includes transverse plane measurements, which are difficult to measure accurately using motion capture. We have developed a method to estimate thigh position modelling the lower limb as a modified slider-crank mechanism. Our model does not rely on cutaneous thigh markers; its motion is defined by a functionally determined hip joint center and constrained distally to the tibial plateau. Motion capture was used to acquire normal gait and countermovement jump data from three unimpaired subjects. The transverse plane translations and rotation along with frontal plane rotation estimated by our model were shown to be reflective of those reported in literature. Our slider-crank model of the pelvis-femur-tibia complex has been demonstrated to perform well in both low and high impact motions

Return to sport activity after anterior cruciate ligament reconstruction in skeletally immature athletes with manual drilling original all inside reconstruction at 8 years follow-up

Objective: Anterior cruciate ligament (ACL) tears are common injuries in adolescent athletes, especially in those who bear high stress on their knees due to shearing forces. The goal of the surgical procedures in skeletally immature patients is to restore joint stability avoiding the adverse effects on the growth process. The aim of this study was to verify the return of the skeletally immature professional athletes to sports in the long-term, following ACL reconstruction with the original all-inside technique and with manual drilling. Methods: This study included 24 athletes (14 boys, 10 girls; mean age: 13.15 years, range: 9e14 years) who had radiographic evidence of open physes, were less than 14 years of age at the time of surgery and those with a minimum follow-up of eight years. All patients completed a questionnaire, the IKDC subjective knee evaluation form, and Tegner Activity Scale. Biomechanical outcomes of the KT-1000 arthrometer, gait analysis, and stabilometric and isokinetic results were also evaluated. A plain radiograph of both lower limbs was taken to obtain a precise measurement of the limb length and mechanical axis angles. Results: The patients returned to sport activities in a mean time of 6.43 months. No rerupture or resurgery due to growth abnormalities was observed. The mean difference in length between the operated and contralateral legs was 0.4 (range: 0.2 to 0.7) cm. The mean side-to-side difference measured with the KT-1000 arthrometer was 5.2 (range: 3.5 to 7) mm in the preoperative and 0.8 (range: 0 to 2.5) mm in the postoperative measurements. Conclusion: In conclusion, the original all-inside technique with manual drilling with a half tunnel and short graft seems to be a very effective technique for the surgical management of ACL injuries in pediatric/ adolescent athletes. A good rate of return to sports at pre-injury levels or higher, high patient satisfaction and a decent motor and proprioceptive function is possible as shown by our analysis. Level of evidence: Level IV, Therapeutic study

Using machine learning to map the European Cleantech sector

This paper is the introductory chapter of a series of analyses that will result from the CLEU1 project, a collaboration between the universities of Politecnico di Torino, Politecnico di Milano and Università degli Studi di Bologna. The project focuses on Cleantech, an industry sector that develops and deploys sustainable and environmentally friendly solutions for various target applications. It aims to: i) analyse the actions that are undertaken by European Cleantech firms to engage in transformative climate and innovation actions to align with the European Green Deal-inspired policies; ii) examine the association of environmental innovation and the number of new investments made by venture capital (VC) investors in Cleantech companies on environmental indicators; iii) analyse the enabling factors for the development of European Cleantech firms, with a focus on EU-level and country-level targeted policies and regulations and the different sources of financing; iv) analyse the extent to which the implementation of policies and regulations affect both the propensity of cleantech firms to seek external equity financing and the equity offering by VC funds

Changes in Plasma \u3b2-NGF and Its Receptors Expression on Peripheral Blood Monocytes During Alzheimer\u2019s Disease Progression

Alzheimer\u2019s disease (AD), the most common cause of dementia, is characterized by the deposition of extracellular amyloid-\u3b2 (A\u3b2) plaques and intracellular neurofibrillary tangles, and by neuroinflammation. During the pathogenesis of AD, monocyte-macrophage lineage cells become increasingly ineffective in clearing A\u3b2 deposits, less able to differentiate, and shift toward pro-inflammatory processes. Beta-nerve growth factor (\u3b2-NGF) and its receptors, TrKA and p75NTR, produce several biological responses, including cell apoptosis and survival, and inflammation. In the central nervous system, the involvement of these receptors in several critical hallmarks of AD is well known, but their role in circulating monocytes during the progression of dementia is unclear. We investigated the relationship between plasma \u3b2-NGF concentration and TrkA/p75NTR receptor expression in monocytes of patients with mild cognitive impairment (MCI), mild AD, and severe AD. We observed that plasma \u3b2-NGF concentration was increased with a higher expression of TrKA, but not of p75NTR, in monocytes from patients with MCI and mild AD, whereas \u3b2-NGF concentration and TrKA expression were decreased and p75NTR expression was increased, associated with caspase 3-mediated apoptosis, in patients with severe AD. In our study, we show evidence of variation in plasmatic \u3b2-NGF and monocytic TrkA/p75NTR receptor expression during the progression of dementia. These novel findings add evidence to support the hypothesis for the involvement of \u3b2-NGF and its receptors on monocytes during AD progression

Impact of Mast Cells on Multiple Sclerosis: Inhibitory Effect of Natalizumab

Mast cells (MCs) derive from a distinct precursor in the bone marrow and are predominantly found in tissues at the interface between the host and the external environment where they can secrete mediators without overt degranulation. Mast cells mature under local tissue microenvironmental factors and are necessary for the development of allergic reactions, through crosslinking of their surface receptors for IgE (FcεRI), leading to degranulation and the release of vasoactive, pro-inflammatory and nociceptive mediators that include histamine, pro-inflammatory and anti-inflammatory cytokines and proteolytic enzymes. Multiple sclerosis (MS) is an autoimmune disease characterized by inflammatory demylination within the central nervous system. MCs are involved in the pathogenesis of MS by generating various vasoactive mediators and cytokines and participate in the destruction of the myelin sheath and the neuronal cells. The process of the development of demyelinating plaques in MS is probably linked with the rupture of the blood-brain barrier by MC products. The effects of natalizumab, which is a very effective drug in reducing the annualized relapse rate and other relapse-based endpoints, are discussed. Here, we report the relationship between MCs and MS

Autoimmunity and parasites.

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