The crucial part in the development of PTA and, in turn, patellar tendinopathy may not be the magnitude of the patellar tendon load but rather the loading patterns. This research provides clinicians with important landing assessment criteria against which to identify athletes at risk of developing patellar tendinopathy.

Age related changes in rib cage geometry were found from measurements made on chest radiographs from 38 individuals aged from 1 month to 31 years and on computed tomography (CT) scans in another 28 individuals, aged from 3 months to 18 years. Chest radiographs were taken for minor respiratory symptoms or fever and only films showing no abnormality were used. CT scans were obtained in children undergoing staging for solid tumours in whom no intrathoracic deposits were found. In infants and very young children the ribs were found to be more horizontal and the sternal clavicular heads and diaphragmatic domes higher than in older children and young adults. Most of these changes were observed in the first two years of life, with something close to the adult pattern by the age of 2 years. Similarly cross sectional chest shape changed from the rounded infantile form to the more ovoid adult form by the same age. The configuration of the ribs observed in infancy and early childhood reduces the potential for thoracic expansion and may contribute to the frequency of respiratory problems found in the very young.Respiratory problems are frequent in childhood and most significant illnesses in preschool children are referrable to the respiratory tract.' The reasons for this age distribution are likely to be the immaturity of the host defences in the lungs and the lesser ability of the respiratory pump to cope with the increased respiratory loads associated with airflow obstruction. The respiratory pump (rib cage, accessory muscles, diaphragm, and abdominal muscles) is thought to be less efficient in the very young child than in the mature adult because of the instability of the thoracic cage and the lower efficiency of the diaphragm.2 Not only is the rib cage more pliable in the very young3 but the ribs also appear to be more horizontal than in the adult.4-6 The pliable rib cage allows the chest wall to move inwards during strong diaphragmatic contraction, while the more horizontal lie of the ribs is likely to limit the potential for thoracic expansion by rib cage movement in the cephalad direction.Although it is known that rib cage geometry changes from early infancy to adulthood, the timing of this change has not be described. MethodsWe examined radiographs in 38 subjects aged 1 month to 31 years and computed tomography (CT) scans of the thorax in 28 children and adolescents aged 3 months to 18 years. CHEST RADIOGRAPHSChest radiographs were taken from the paediatric accident and emergency department at Guy's Hospital and from adults having routine films taken before employment at the Brompton Hospital. Radiographs which were poorly orientated, as assessed by the position of the sternal heads of the clavicles in relation to the spine, were excluded, as were films from any subject with a history of wheezing, asthma, or recent pneumonia. All of the children underwent radiographic examination because of minor respiratory symptoms or fever, and only those films showing no abnormality were accepted for the study. Clear c...

An easily implemented, reliable, and valid movement screening tool composed of three criteria enables coaches and/or clinicians to predict the presence and severity of a PTA in asymptomatic athletes. This enables identification of asymptomatic athletes at higher risk of developing patellar tendinopathy, which allows the development of effective preventative measures to aid in the reduction of patellar tendinopathy injury prevalence.

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Excessive extensor mechanism loading from repeated landing has been associated with overuse knee injuries, especially patellar tendinopathy. In order to reduce these loads, it is important to establish which landing task places the highest load on the patellar tendon. It was hypothesized that the horizontal landing would create higher patellar tendon force (F(PT)) compared with the vertical landing. Sixteen male athletes with healthy patellar tendons performed five successful trials of a stop-jump task, which involved a symmetrical two-foot landing after a horizontal approach (horizontal landing) followed by another symmetrical two-foot landing after a vertical jump (vertical landing). For both lower limbs during each trial, the participants' ground reaction forces were recorded, three-dimensional kinematics measured and F(PT) calculated by dividing the net knee joint moment by the patellar tendon moment arm. Compared with the vertical landing, significantly higher F(PT), posterior ground reaction forces and F(PT) loading rates were generated during the horizontal landing, despite lower vertical ground reaction forces (F(V)), highlighting the notion that F(V) should not be used to reflect F(PT). Understanding that a horizontal landing task places the highest load on the patellar tendon, provides an appropriate framework for future research to investigate lower limb landing strategies in athletes with patellar tendinopathy.