Oral Supplementation of Specific Collagen Peptides Combined with Calf-Strengthening Exercises Enhances Function and Reduces Pain in Achilles Tendinopathy Patients.

The current pilot study investigates whether oral supplementation of specific collagen peptides improves symptoms and tendon vascularisation in patients with chronic mid-portion Achilles tendinopathy in combination with structured exercise. Participants were given a placebo or specific collagen peptides (TENDOFORTE®) in combination with a bi-daily calf-strengthening program for 6 months. Group AB received specific collagen peptides for the first 3 months before crossing over to placebo. Group BA received placebo first before crossing over to specific collagen peptides. At baseline (T1), 3 (T2) and 6 (T3) months, Victorian Institute of Sports Assessment⁻Achilles (VISA-A) questionnaires and microvascularity measurements through contrast-enhanced ultrasound were obtained in 20 patients. Linear mixed modeling statistics showed that after 3 months, VISA-A increased significantly for group AB with 12.6 (9.7; 15.5), while in group BA VISA-A increased only by 5.3 (2.3; 8.3) points. After crossing over group AB and BA showed subsequently a significant increase in VISA-A of, respectively, 5.9 (2.8; 9.0) and 17.7 (14.6; 20.7). No adverse advents were reported. Microvascularity decreased in both groups to a similar extent and was moderately associated with VISA-A (Rc²:0.68). We conclude that oral supplementation of specific collagen peptides may accelerate the clinical benefits of a well-structured calf-strengthening and return-to-running program in Achilles tendinopathy patients.

Effects of Altering Trunk Position during Landings on Patellar Tendon Force and Pain.

PURPOSE: This study aimed to verify the immediate effects of altering sagittal plane trunk position during jump landings on lower limb biomechanics, patellar tendon force, and pain of athletes with and without patellar tendinopathy. METHODS: Twenty-one elite male athletes were categorized into three groups: athletes with patellar tendinopathy (TG; n = 7), asymptomatic athletes with patellar tendon abnormalities (n = 7), and asymptomatic athletes without tendon abnormalities (CG; n = 7). A biomechanical evaluation was conducted while the athletes performed drop landings from a bench in a self-selected trunk position (SS). Afterward, the athletes were randomly assigned to land with either a flexed trunk position (FLX) or an extended trunk position (EXT). Variables of interest for this study included sagittal plane peak kinematics, kinetics, patellar tendon force, and pain during the landing tasks. RESULTS: Peak patellar tendon force, knee extensor moment, and knee pain decreased in the FLX landing compared with the SS landing, regardless of group. In addition, peak patellar tendon force, knee extensor moment, and vertical ground reaction force were smaller in the FLX landing compared with the EXT landing. The TG had smaller peak ankle dorsiflexion compared with the CG during jump landings, regardless of trunk position. CONCLUSIONS: Landing with greater trunk flexion decreased patellar tendon force in elite jumping athletes. An immediate decrease in knee pain was also observed in symptomatic athletes with a more flexed trunk position during landing. Increasing trunk flexion during landing might be an important strategy to reduce tendon overload in jumping athletes.

El continuum de la patología de tendón: concepto actual e implicaciones clínicas / The continuum of tendon pathology: Current view and clinical implications

El modelo del continuum fue propuesto por Cook y Purdam en 2009 con el propósito de mejorar la comprensión del complejo marco que rodea la patología del tendón. El concepto se basa en las características de los tres estados tisulares del tendón: tendón reactivo, tendinopatía desestructurada y tendinopatía degenerativa. El concepto del continuum se diferencia de las otras propuestas por su visión de cambio continuo de la estructura del tejido tendinoso. Cada fase tiene una presentación clínica característica y un tratamiento específico. Estudios histológicos, por la imagen y clínicos corroboran con evidencia el abordaje de esta patología mediante el concepto del modelo de continuum (AU)

Cook and Purdam first proposed the Continuum model in 2009, with the aim of improving the understanding of the complexity of tendon pathologies. The Continuum is based on three states of tendon structure: reactive tendon, tendon disrepair and degenerative tendon. In contrast to other proposals, the Continuum model describes continuous changes in tendon structure. Each state of tendon structure represents a particular clinical presentation and requires a particular type of management. Evidence seen in histopathological studies, imaging and clinical studies all support the Continuum model for the analysis of tendon pathologies (AU)

Asymptomatic players with a patellar tendon abnormality do not adapt their landing mechanics when fatigued.

This study aimed to explore how asymptomatic athletes with a patellar tendon abnormality (PTA), who are at high risk of developing patellar tendinopathy, alter their landing technique and net patellar tendon loads generated in response to fatigue. Seven asymptomatic players with a PTA performed five successful vertical stop-jump trials before and after a fatigue protocol. Fatigue protocol involved participants repeatedly performing sets of 30 submaximal jump exercises on a sledge apparatus followed by 30 s rest until the task failure criteria were reached. Three-dimensional ground reaction forces, lower limb kinematics and net peak patellar tendon force were recorded during the stop-jump task. No significant between-fatigue condition differences in net patellar tendon loading, or most secondary outcome variables were observed. Only some fatigue changes were seen during the vertical landing phase. Asymptomatic PTA participants did not modify their landing technique or net patellar tendon loading during a stop-jump task in response to fatigue. The lack of between-fatigue condition differences displayed by the asymptomatic PTA participants during both landing phases suggest that these individuals may not be capable of sufficient movement variability in their landing strategies to adapt to fatigue.

Proximal Hamstring Tendinopathy: Clinical Aspects of Assessment and Management.

Synopsis Proximal hamstring tendinopathy (PHT) typically manifests as deep buttock pain at the hamstring common origin. Both athletic and nonathletic populations are affected by PHT. Pain and dysfunction are often long-standing and limit sporting and daily functions. There is limited evidence regarding diagnosis, assessment, and management; for example, there are no randomized controlled trials investigating rehabilitation of PHT. Some of the principles of management established in, for example, Achilles and patellar tendinopathy would appear to apply to PHT but are not as well documented. This narrative review and commentary will highlight clinical aspects of assessment and management of PHT, drawing on the available evidence and current principles of managing painful tendinopathy. The management outline presented aims to guide clinicians as well as future research. J Orthop Sports Phys Ther 2016;46(6):483-493. Epub 15 Apr 2016. doi:10.2519/jospt.2016.5986.

Forearm position's alteration of radial-head impingement on wrist-extensor tendons.

CONTEXT: Lateral epicondylalgia, pain at the lateral elbow, is commonly associated with extensor carpi radialis brevis tendinopathy. The radial head, which abuts the extensor tendons and is elliptical in shape, may affect the extensor tendons during pronation of the forearm. Cadaverous studies have shown that the radial head may act as a cam in pronation, to offer a mechanical advantage to the common extensor tendon and to mitigate load on the origin of the extensor carpi radialis brevis tendon. OBJECTIVE: To determine the effect of radial-head position on the wrist-extensor tendons in vivo. DESIGN: Repeated-measures design. SETTING: Laboratory. PARTICIPANTS: 22 participants (12 male, 2 left-handed). MAIN OUTCOME MEASURES: Distance (mm) from subcutaneous fascia to radial head measured by ultrasound. RESULTS: The radial head in supination was significantly deeper than either pronation or midprone, indicating a smaller cam effect in supination. CONCLUSION: The authors recommend that the effect of radial-head position and its relationship to the area of tendon pathology be considered clinically in the rehabilitation of patients suffering from lateral epicondylalgia.

Alterations to landing technique and patellar tendon loading in response to fatigue.

PURPOSE: Fatigue may contribute to knee joint injuries, such as patellar tendinopathy, by increasing joint loading and altering lower limb landing technique, which in turn may increase tissue loading. This study aimed to investigate the effect of lower limb muscle fatigue on the landing technique and patellar tendon loads generated during the horizontal and vertical landing phases of a stop-jump task. It was hypothesized that muscle fatigue would increase patellar tendon loading and alter the landing technique displayed during the horizontal, but not the vertical, landing phase of the stop-jump task. METHODS: Sixteen men, recruited from team sports involving repetitive landing, performed repeated trials of a stop-jump task. During each trial, the participants' ground reaction forces and electromyographic activity of seven lower limb muscles were recorded, three-dimensional kinematics measured, and peak patellar tendon force (FPT) calculated. RESULTS: When fatigued, participants generated a significantly lower FPT and FPT loading rate, despite a higher vertical ground reaction force (FV) and FV loading rate, during the horizontal landing phase of the stop-jump task. During the vertical landing phase, participants displayed only minor changes to the kinetics and kinematics of their landing in response to fatigue, although fatigue caused substantial alterations to their lower limb muscle activation patterns during landing. CONCLUSIONS: During the horizontal landing phase of the stop-jump task, participants decreased their patellar tendon load when they were fatigued by altering their lower limb landing technique, including a reduced net knee joint extension moment associated with less knee and hip flexion. This decrease in patellar tendon loading when fatigued may be an inherent protective strategy to potentially decrease loading of the tendon during repetitive landing.

Sports and exercise-related tendinopathies: a review of selected topical issues by participants of the second International Scientific Tendinopathy Symposium (ISTS) Vancouver 2012.

In September 2010, the first International Scientific Tendinopathy Symposium (ISTS) was held in Umeå, Sweden, to establish a forum for original scientific and clinical insights in this growing field of clinical research and practice. The second ISTS was organised by the same group and held in Vancouver, Canada, in September 2012. This symposium was preceded by a round-table meeting in which the participants engaged in focused discussions, resulting in the following overview of tendinopathy clinical and research issues. This paper is a narrative review and summary developed during and after the second ISTS. The document is designed to highlight some key issues raised at ISTS 2012, and to integrate them into a shared conceptual framework. It should be considered an update and a signposting document rather than a comprehensive review. The document is developed for use by physiotherapists, physicians, athletic trainers, massage therapists and other health professionals as well as team coaches and strength/conditioning managers involved in care of sportspeople or workers with tendinopathy.

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

PURPOSE: When investigating lower limb landing biomechanics, researchers often assume movement symmetry between a participant's 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.

Clinical features of patellar tendinopathy and their implications for rehabilitation.

This study investigated the clinical features of patellar tendinopathy (PT), with focus on individuals with unilateral and bilateral PT. A cross-sectional study design was employed to compare individuals with unilateral (n = 14) or bilateral (n = 13) PT and those without PT (control, n = 31). Features assessed included thigh strength (normalized peak knee extensor torque) and flexibility (sit-and-reach and active knee extension), calf endurance (heel-rise test), ankle flexibility (dorsiflexion), alignment measures (arch height and leg length difference), and functional measures (hop for distance and 6 m hop test). Groups were matched for age and height; however, unilateral and bilateral PT had greater mass with a higher body mass index (BMI) than control. Also, bilateral PT performed more sport hours per week than both unilateral PT and control. Unilateral PT had less thigh strength than control and bilateral PT, whereas bilateral PT had more thigh flexibility than control and unilateral PT. Both unilateral and bilateral PT had altered alignment measures compared to control. Features that predicted symptoms in PT were lower thigh flexibility and strength, whereas those that predicted function were higher thigh strength and lower ankle flexibility. These findings indicate that unilateral and bilateral PT represent distinct entities, and that thigh strength appears particularly important in PT as it predicted both symptoms and function in PT.

Rehabilitation of lower limb tendinopathies.

Tendon rehabilitation requires an extensive assessment, and identification of deficits that impact on sporting performance. Rehabilitation must address all these deficits and may take several months. Return to sport may require short- or long-term load modification. Surgery also requires a long recovery time, and may not guarantee a return to sport.