Patellar tendinopathy: pathomechanics and a modern approach to treatment

Patellar tendinopathy, a common condition in sport, can be recurrent and resistant to treatment, Risk factors include the level of training, biomechanics, and genetic factors. This review discusses several programs based on eccentric exercise and suggests principles for nonoperative treatment including improving shock absorption, load modification, and adaptation of the tendon to sporting stress. The level of pain that patients are asked to tolerate during tendon-exercise programs varies among programs, and it is unclear what level is optimal to stimulate tendon recovery. Rehabilitation presents several challenges: It can take a long time (3-12 months), exercise prescription in an athlete who is continuing to compete is not straightforward, and guidelines for treatment progression are poor, Nonoperative treatment can fail because of inappropriate exercise prescription and poor athlete compliance. If this occurs and surgical intervention is required, the athlete might still have an unpredictable outcome. Solutions to these problems require additional clinical research.<br /

EFFECTS OF FATIGUE ON PATELLAR TENDON LOADING DURING THE LANDING PHASES OF A STOP-JUMP MOVEMENT

Therefore, the purpose of this study was to establish whether there were any significant differences in the patellar tendon forces generated by athletes during the landing phases of a stop-jump (SJ) movement before and after fatigue induced by repetitive SSC exercises. Eighteen soccer and basketball players performed a SJ movement before and after a fatigue protocol. During each SJ trial, three-dimensional kinematic, kinetic and electromyographic data for each subject’s lower limbs were recorded. When fatigued, athletes significantly (p < 0.05) reduced their patellar tendon forces during the SJ movement by reducing knee and hip flexion. Whether “stiff limb” landings reduces the risk of developing patellar tendinopathy by decreasing patellar tendon loading during jumping requires further investigation

ICON 2019: International Scientific Tendinopathy Symposium Consensus: Clinical Terminology

© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.Background Persistent tendon pain that impairs function has inconsistent medical terms that can influence choice of treatment.1 When a person is told they have tendinopathy by clinician A or tendinitis by clinician B, they might feel confused or be alarmed at receiving what they might perceive as two different diagnoses. This may lead to loss of confidence in their health professional and likely adds to uncertainty if they were to search for information about their condition. Clear and uniform terminology also assists inter-professional communication. Inconsistency in terminology for painful tendon disorders is a problem at numerous anatomical sites. Historically, the term ‘tendinitis’ was first used to describe tendon pain, thickening and impaired function (online supplementary figure S1). The term ‘tendinosis’ has also been used in a small number of publications, some of which were very influential.2 3 Subsequently, ‘tendinopathy’ emerged as the most common term for persistent tendon pain.4 5 To our knowledge, experts (clinicians and researchers) or patients have never engaged in a formal process to discuss the terminology we use. We believe that health professionals have not yet agreed on the appropriate terminology for painful tendon conditions.Peer reviewedFinal Accepted Versio

Differential Activation Of Medial And Lateral Hamstring Muscles In Loading Challenges: A Pilot Study: 1615: Board #105

Hamstring strain injuries are the most common muscle injury in Australian Rules Football. 80% of these involve the lateral hamstring group. Recurrence rate on return to play is reported to be 30%. Many exercises utilised in rehabilitation treat the hamstring muscles as a single group with sagittal plane exercise. Recent studies have identified differential activation of the medial and lateral hamstring groups in cutting manoeuvres similar to those encountered in Australian Rules Football. PURPOSE: To evaluate a variety of exercise challenges to determine if differential activation of the medial and lateral hamstring muscles can be achieved during rehabilitation. We hypothesised increased specificity may better optimise activation and possibly loading of the lateral hamstring group in particular, which has little in the way of synergists over the hip and knee. METHODS: Healthy adult participants with no history of hamstring muscle injury undertook a variety of isometric exercise challenges in random order. Two of these exercises comprised resisted knee flexion (at 80° knee flexion) in 0° and 45°hip flexion. Further exercises involved a hamstring bridge on a stable or unstable surface (Swiss Ball). A single leg trunk flexion exercise was also included. All exercises were performed with neutral, internal and external rotation of the knee. Activation of the biceps femoris (lateral hamstring) and semimembranosus (medial hamstring) was measured using surface electromyography (EMG) during maximal 5 s isometric holds. RESULTS: Challenges that elicited greatest activation of the lateral hamstring group were a hamstring bridge with external rotation of the hip and knee followed by a hamstring bridge in neutral. Greatest activation of the medial hamstring occurred during prone knee flexion in 0° hip flexion and internal rotation, followed by hamstring bridging on a Swiss ball with internal rotation. CONCLUSION: This pilot study identified hamstring loading challenges that offer greater specificity in activation of the medial and lateral hamstring muscles. These challenges may be useful in targeted rehabilitation of the lateral or medial hamstring muscles. In interpreting our findings it should be noted that activation levels do not necessarily correspond to muscle loads

Conservative treatment of patellar tendinopathy

Patellar tendinopathy disrupts athletic careers in several sports and is resistant to many forms of conservative treatment. Outcome after conservative treatment has been minimally investigated, and the effect of these treatments on the pathology of overuse tendinopathy are not well understood.The clinical assessment of patellar tendinopathy appears straightforward, but evidence suggests that the importance of imaging and palpation in diagnosis and ongoing assessment may be overestimated. There is a lack of clinically relevant research on which to base treatment. However, the principles of management for patellar tendinopathy derived from clinical experience include load modification, musculotendinous rehabilitation, and intervention to improve the shock absorbing capacity of the limb. The role of electrophysical agents, massage, and stretching in the treatment of patellar tendinopathy are also discussed. The progression of treatment is based on clinical grounds due to a lack of reliable subjective and objective tools to assess recovery.The failure of some conservative programs could be due to either athlete compliance or practitioner expertise. The management of patellar tendinopathy is complex, and if the physiotherapist addresses all the principles of treatment, the chance of success could be increased.<br /

Effects of fatigue on patellar tendon loading during the landing phases of a stop-jump movement

Therefore, the purpose of this study was to establish whether there were any significant differences in the patellar tendon forces generated by athletes during the landing phases of a stop-jump (SJ) movement before and after fatigue induced by repetitive SSC exercises. Eighteen soccer and basketball players performed a SJ movement before and after a fatigue protocol. During each SJ trial, three-dimensional kinematic, kinetic and electromyographic data for each subject’s lower limbs were recorded. When fatigued, athletes significantly (p \u3c 0.05) reduced their patellar tendon forces during the SJ movement by reducing knee and hip flexion. Whether “stiff limb” landings reduces the risk of developing patellar tendinopathy by decreasing patellar tendon loading during jumping requires further investigation

Landing strategies of athletes with an asymptomatic patellar tendon abnormality

Purpose: Risk factors associated with a clinical presentation of patellar tendinopathy are patellar tendon ultrasonographic abnormality (PTA) and excessive loading. It remains unknown whether characteristics of an athlete\u27s landing technique contribute to this excessive patellar tendon loading. This study investigated whether asymptomatic athletes with and without PTA had different landing strategies and hypothesized that asymptomatic athletes with a PTA would create higher patellar tendon loading and a different lower-limb landing strategy compared with athletes with normal patellar tendons. Methods: Seven athletes with no previous history or clinical signs of patellar tendon injury with a PTA were matched to athletes with normal patellar tendons (controls). Participants performed five successful trials of a stop-jump task, which involved a simultaneous two-foot horizontal and then vertical landing. During each trial, the participants\u27 ground reaction forces and lower-limb electromyographic data were recorded, the three-dimensional kinematics measured, and the peak patellar tendon force calculated by dividing the net knee joint moment by the patellar tendon moment arm. Results: Significant between-group differences in landing technique were mostly observed during the horizontal landing phase. Participants with a PTA created similar patellar tendon loading to the controls, but with altered sequencing, by landing with significantly greater knee flexion and extending their hips while the controls flexed their hips as they landed, reflecting a different muscle recruitment order compared with the PTA group. Conclusions: 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

Lower limb movement symmetry cannot be assumed when investigating the stop-jump landing

Assumed When Investigating the Stop-Jump Landing. Med. Sci. Sports Exerc., Vol. 44, No. 6, pp. 1123-1130, 2012. Purpose: When investigating lower limb landing biomechanics, researchers often assume movement symmetry between a participant\u27s right and left lower limbs for the simplicity of data collection and analysis, although landing tasks often involve dual-limb motion. However, whether lower limb symmetry can be assumed when investigating dynamic, sport-specific movements such as the stop-jump has not been investigated. Therefore, this study aimed to determine whether there were any significant differences in selected kinetic, kinematic, and muscle activation patterns characterizing lower limb biomechanics displayed by the dominant limb compared with the nondominant limb of participants during a stop-jump task. Methods: Sixteen male athletes with normal patellar tendons on diagnostic imaging performed five successful stop-jump trials. Patellar tendon forces (FPT), ground reaction forces, three-dimensional kinematics, and EMG activity of seven lower limb muscles were recorded for the dominant and nondominant lower limbs during each trial. Results: During the horizontal landing phase, the dominant lower limb sustained a significantly higher FPT and peak net knee joint extension moment compared with the nondominant lower limb. Furthermore, during the vertical landing phase, the dominant lower limb sustained significantly lower vertical but higher posterior ground reaction forces compared with the nondominant lower limb. Other variables did not significantly vary as a function of lower limb dominance. Conclusions: It is recommended that researchers clearly identify their primary outcome variables and ensure that their experimental design, particularly in terms of lower limb dominance, provides an appropriate framework to investigate possible mechanics underlying unilateral and bilateral knee joint injuries during dual-limb movements such as the stop-jump task