The effects of initial conditions and takeoff technique on running jumps for height and distance.

This study used a subject-specific model with eight segments driven by joint torques for forward dynamics simulation to investigate the effects of initial conditions and takeoff technique on the performance of running jumps for height and distance. The torque activation profiles were varied in order to obtain matching simulations for two jumping performances (one for height and one for distance) by an elite male high jumper, resulting in a simulated peak height of 1.98m and a simulated horizontal distance of 4.

Evidence-supported rehabilitation of patellar tendinopathy.

Chronic tendinopathy is a common musculoskeletal disorder that frequently affects athletes who train and compete at all levels. This Clinical Commentary presents a review of the etiology, incidence, and contributory factors related specifically to patellar tendinopathy. Examination and differential diagnosis considerations are provided, and an evidence-based, staged rehabilitation program is described.

Infrapatellar Straps Decrease Patellar Tendon Strain at the Site of the Jumper's Knee Lesion: A Computational Analysis Based on Radiographic Measurements.

Background: The impetus for the use of patellar straps in the treatment of patellar tendinopathy has largely been based on empirical evidence and not on any mechanistic rationale. A computational model suggests that patellar tendinopathy may be a result of high localized tendon strains that occur at smaller patella-patellar tendon angles (PPTAs).

Hypothesis: Infrapatellar straps will decrease the mean localized computational strain in the area of the patellar tendon commonly involved in jumper's knee by increasing the PPTA.

Intratendinous tophaceous gout imitating patellar tendonitis in an athletic man.

Patellar tendon-related pain is common in the athletic patient. When it occurs in skeletally mature patients participating in running, jumping, or kicking sports, the diagnosis of jumper's knee patellar tendonitis is usually made. If patellar tendon pain is associated with a mass, the differential diagnosis should be broadened to include crystalline arthropathy.

Sclerosing polidocanol injections or arthroscopic shaving to treat patellar tendinopathy/jumper's knee? A randomised controlled study.

Background: Proximal patellar tendinopathy/jumper's knee (PT/JK) is well known to be difficult to treat. Recent studies using an ultrasound and colour Doppler-based treatment approach on the dorsal side of the tendon, sclerosing polidocanol injections and ultrasound-guided arthroscopic shaving, have shown promising clinical results.

Objectives: To compare the clinical effects after treatment with sclerosing polidocanol injections and arthroscopic shaving.

Moment-angle relations in the initial time of contraction.

Standard moment-angle relations are typically obtained for values at maximum of contraction. Muscle properties for contraction times, similar to the short times of powerful athletic activities, may be more important than muscle properties that are obtained at maximum (TMAX) of contraction. The research question was whether moment-angle relations obtained during the initial time course of contraction are linearly scaled reflections of moment-angle relations obtained at maximum of contraction.

Bilateral asymmetry in joint torque during squat exercise performed by long jumpers.

This study aimed to examine the bilateral differences in movement and joint torques during the squat exercise by using kinematic and kinetic analyses. Eighteen long jumpers participated in this study. They performed 3 repetitions of the squat exercise with loads of 50, 70, and 90% of their 3 repetition maximum (3RM).

Kinematic characteristics of the ski jump inrun: a 10-year longitudinal study.

The athlete's inrun position affects the outcome for take-off in ski jumping. The purpose of this study was to examine the kinematic parameters between skiers' adjacent body segments during their first straight path of the inrun. Elite ski jumpers participated in the study at the World Cup events in Innsbruck, Austria, during the years 1992 through 2001.

A preliminary study of patellar tendon torques during jumping.

The etiology of patellar tendinopathy (jumper's knee) has been attributed to a significant increase in patellar tendon torques associated with jumping. While some investigators have suggested that patellar tendon torques are greater during takeoff, little is known about the relative magnitudes of patellar tendon torques during takeoff and landing. We hypothesized that peak patellar tendon torques are greater in jump takeoff than in landing, and that there is a linear correlation between jump height and peak patellar tendon torque.

Neuromechanical evidence of improved neuromuscular control around knee joint in volleyball players.

The aim of the present work was to verify that skilled volleyball players present specific adaptations in both neuromuscular control and movement biomechanics, showing an improved neuromuscular control around the knee joint than in non-jumper athletes. Seven male volleyball players and seven male non-jumper athletes were recruited for this study. The following tests were performed in a random order: single countermovement jump (CMJ), single squat jump.

Use of platelet-rich plasma for the treatment of refractory jumper's knee.

The aim of this study was to evaluate the efficacy of multiple platelet-rich plasma (PRP) injections on the healing of chronic refractory patellar tendinopathy after previous classical treatments have failed. We treated 15 patients affected by chronic jumper's knee, who had failed previous nonsurgical or surgical treatments, with multiple PRP injections and physiotherapy. We also compared the clinical outcome with a homogeneous group of 16 patients primarily treated exclusively with the physiotherapy approach.

Risk factors for developing jumper's knee in sport and occupation: a review.

Background: The onset of jumper's knee is generally associated with sports and sporting activities. Employees in certain professions might be at risk as well for developing jumper's knee. Therefore, it is of interest to identify risk factors in sport and/or occupation.

Platelet-rich plasma: new clinical application: a pilot study for treatment of jumper's knee.

This study describes a simple, low-cost, minimally invasive way to apply PRP growth factors to chronic patellar tendinosis; 20 male athletes with a mean history of 20.7 months of pain received treatment, and outcomes were prospectively evaluated at 6 months follow-up. No severe adverse events were observed, and statistically significant improvements in all scores were recorded.

Compensatory mechanisms in basketball players with jumper's knee.

Context: Determining whether there are compensations in those with jumper's knee (JK) might further our understanding of the condition.

Objective: Comparing lower extremity kinematics and jump performance of basketball athletes with JK with those of healthy controls (C).

Design: Repeated-measures control-match design.

Overload syndromes of the knee in adolescents: Sonographic findings.

Overload syndromes are caused by repetitive microtrauma, and the knee joint is most frequently affected in adolescents. The reason for this is that the knee joint is engaged in almost all sports activities. Pathologies related to the anterior aspect of the knee are: femoropatellar pain, jumper's knee syndromes, Osgood-Schlatter disease, Sinding-Larsen-Johansson syndrome and patellar stress fractures; to the medial aspect: semimembranous tendon enthesopathy and pes anserinus bursitis; to the lateral aspect: iliotibial band syndrome (runner's knee), popliteus and femoral biceps tendon enthesopathy; to the posterior aspect: fabella syndrome and medial gastrocnemius muscle tendon enthesopathy.

[Patellar tendinopathy ('jumper's knee'); a common and difficult-to-treat sports injury].

Patellar tendinopathy is a common and difficult-to-treat overuse injury of the patellar tendon with a very negative impact on the careers of many athletes. It appears to involve a failed healing process in the tendon--not inflammation--and has consequences for the treatment strategy. Rehabilitation programs are based on the principles of load reduction and an eccentric exercise program to improve muscle-tendon function and optimize the kinetic chain.

Jumper's knee in volleyball athletes: advancements in diagnosis and treatment.

Jumper's knee, or patellar tendinopathy, affects nearly one half of elite volleyball athletes and causes significant morbidity. The diagnosis and treatment of jumper's knee is evolving with heavier reliance on the use of diagnostic ultrasound with and without color or power Doppler. Research suggests that conservative treatment is very effective using an eccentric exercise regimen and decline squats.

Patellar tendon strain is increased at the site of the jumper's knee lesion during knee flexion and tendon loading: results and cadaveric testing of a computational model.

Background: Patellar tendinopathy (jumper's knee) is characterized by localized tenderness of the patellar tendon at its origin on the inferior pole of the patella and a characteristic increase in signal intensity on magnetic resonance imaging at this location. However, it is unclear why the lesion typically occurs in this area of the patellar tendon as surface strain gauge studies of the patellar tendon through the range of motion have produced conflicting results.

Hypothesis: The predicted patellar tendon strains that occur as a result of the tendon loads and patella-patellar tendon angles (PPTAs) experienced during a jump landing will be significantly increased in the area of the patellar tendon associated with patellar tendinopathy.

Color Doppler ultrasound findings in patellar tendinopathy (jumper's knee).

Background: Recent studies have revealed structural changes with neovessels in patients with jumper's knee and Achilles tendinopathy, and treatment with sclerosing injections has shown promising clinical results.

Purpose: To study the prevalence of neovascularization and structural tendon changes on color Doppler ultrasound examination in elite athletes with clinical symptoms of jumper's knee and to examine the ultrasound characteristics of the tendon after sclerosing injection treatment with polidocanol.

Study Design: Cohort study; Level of evidence, 3.

Muscular strength and jumping performance relationships in young women athletes.

The relationships between muscular strength and vertical jumping performance were examined in young women (14-19 years) track and field jumpers (n = 20) and volleyball players (n = 21). The knee extensor muscular strength measured at 9 knee angles was correlated with jumping height and peak power at the squat (SJ) and the countermovement (CMJ) vertical jump tests. Pearson product coefficient of correlation was used to test the significance of these relationships (p View Article and Find Full Text PDF

Augmented feedback reduces ground reaction forces in the landing phase of the volleyball spike jump.

Context: Frequency and magnitude of ground reaction forces (GRF) have been implicated in causing injuries such as "jumpers knee."

Objective: To investigate whether a single session of augmented feedback concerning landing technique would decrease GRF.

Design: Pretest posttest experimental design.

[Arthroscopic treatment of chronic tendinosis of the patellar tendon (Jumper's Knee): surgical technique].

The described surgical technique with the arthroscopic resection of the lower patellar pole for the treatment of chronic patellar tendinosis leads to excellent clinical results. It combines the advantages of a minimal-invasive method with fast rehabilitation and return to sporting activities with comparable results to described open procedures.

Coordination variability and skill development in expert triple jumpers.

The aim of this study was to examine the influence of skill of expert triple jumpers on the coordination variability of lower extremity intra-limb couplings. In contrast to the traditional motor learning perspective, we hypothesized that as skill and thus performance increases, movement coordination variability will also increase. Three-dimensional kinematic and ground reaction force data were collected during the hop-step transition phase of the triple jump.

Arthroscopic resection of the lower patellar pole in patients with chronic patellar tendinosis.

Purpose: The aim of this prospective study is to evaluate the clinical results of arthroscopic resection of the lower patellar pole in patients with patellar tendinosis.

Methods: Twenty patients underwent an arthroscopic resection of the lower patellar pole between 2002 and 2004. All of them were evaluated at 6 weeks and 3, 6, 12, and 24 months after surgery using the Tegner activity level, the Lysholm score, the Kujala score, a modified jumper's knee classification according to Blazina, and visual analog scales for pain, function, and satisfaction.

[Jumper's knee. Surgery and arthroscopic treatment with scraping and povidone collagen in high-performance athletes].

Unlabelled: The jumper's knee or patellar tendonitis is a common injury in the athlete with an incidence between 14% and 16% among high-performance athletes. In addition to an overuse injury, there are some intrinsic factors for its development. Conservative treatment is indicated for the initial form, but when it fails, surgical treatment should be performed with an appropriate rehabilitation program.