The AGE Reader: A non-invasive method to assess long-term tissue damage.

AIMS: Advanced glycation endproducts (AGEs) are sugar-modified adducts which arise during non-enzymatic glycoxidative stress. These compounds may become systemically elevated in disease states, and accumulate in tissue, especially on long-lived proteins. AGEs have been implicated in various acute, and chronic diseases, stressing the need for reliable and comprehensive measuring techniques. Measurement of AGEs in tissue such as skin requires invasive skin biopsies. The AGE Reader has been developed to assess skin autofluorescence (SAF) non-invasively using the fluorescent properties of several AGEs. RESULTS/CONCLUSION: Various studies have shown that SAF is a useful marker of disease processes associated with oxidative stress. It is prospectively associated with the development of cardiovascular events in patients with diabetes, renal or cardiovascular disease, and it predicts diabetes, cardiovascular disease, and mortality in the general population. However, when measuring SAF in individual subjects, several factors may limit the reliability of the measurement. These include endogenous factors present in the skin that absorb emission light such as melanin in dark-skinned subjects, but also factors that lead to temporal changes in SAF such as acute diseases and strenuous physical exercise associated with glycoxidative stress. Also, exogenous factors could potentially influence SAF levels inadvertently such as nutrition, and for example the application of skin care products. This review will address the AGE Reader functionality and the endogenous, and exogenous factors which potentially influence the SAF assessment in individual subjects.

Bilateral changes in tendon structure of patients diagnosed with unilateral insertional or midportion achilles tendinopathy or patellar tendinopathy.

PURPOSE: Changes in tendon structure are commonly seen in patients with unilateral achilles (AT) or patellar (PT) tendinopathy but might also be present on the asymptomatic side, indicating a higher risk for developing symptoms. The aim of this study is to compare tendon structure of the symptomatic side with the asymptomatic side in AT and PT patients and control subjects. METHODS: A total of 46 patients with unilateral AT (16 insertional and 30 midportion) and 38 with unilateral PT were included. For the control group, a total of 18 Achilles tendons and 25 patellar tendons were scanned. Tendon structure was assessed using ultrasound tissue characterisation (UTC), which quantifies tendon organisation dividing the structure into four different echo types (I-IV). RESULTS: There were significant differences in echo types I, III, and IV between symptomatic and asymptomatic sides and controls. Additionally, there was a significant difference between the symptomatic and the asymptomatic side for all tendinopathy locations. In the insertional AT tendon portion, the symptomatic side showed a higher percentage of echo type III. For the midportion AT, the symptomatic side showed a lower percentage of echo type I and a higher percentage of echo types III and IV. For the patellar tendon, the symptomatic side showed a higher percentage of echo types III and IV. All differences were higher than the minimal detectable changes. CONCLUSION: Although patients have symptoms unilaterally, the tendon structures are compromised on both sides. These results stress the importance of monitoring both symptomatic and asymptomatic tendon structures and in addition highlight that the asymptomatic side should not be used as reference in clinical practice. LEVEL OF EVIDENCE: III.

Does the adolescent patellar tendon respond to 5 days of cumulative load during a volleyball tournament?

Patellar tendinopathy (jumper's knee) has a high prevalence in jumping athletes. Excessive load on the patellar tendon through high volumes of training and competition is an important risk factor. Structural changes in the tendon are related to a higher risk of developing patellar tendinopathy. The critical tendon load that affects tendon structure is unknown. The aim of this study was to investigate patellar tendon structure on each day of a 5-day volleyball tournament in an adolescent population (16-18 years). The right patellar tendon of 41 players in the Australian Volleyball Schools Cup was scanned with ultrasound tissue characterization (UTC) on every day of the tournament (Monday to Friday). UTC can quantify structure of a tendon into four echo types based on the stability of the echo pattern. Generalized estimating equations (GEE) were used to test for change of echo type I and II over the tournament days. Participants played between eight and nine matches during the tournament. GEE analysis showed no significant change of echo type percentages of echo type I (Wald chi-square = 4.603, d.f. = 4, P = 0.331) and echo type II (Wald chi-square = 6.070, d.f. = 4, P = 0.194) over time. This study shows that patellar tendon structure of 16-18-year-old volleyball players is not affected during 5 days of cumulative loading during a volleyball tournament.

Effect of patellar strap and sports tape on pain in patellar tendinopathy: A randomized controlled trial.

Numerous athletes with patellar tendinopathy (PT) use a patellar strap or sports tape during sports. This study's aim was to investigate the short-term effect of these orthoses on patellar tendon pain. Participants performed the single-leg decline squat, vertical jump test, and triple-hop test under four different conditions (patellar strap, sports tape, placebo, and control). Subsequently, participants practiced sports as usual for 2 weeks; during 1 week, they were assigned to one of the four conditions. Pain was measured with the visual analog scale (VAS). In total, 97 athletes with PT [61% male, age 27.0 (SD8.1), VISA-P 58.5 (SD12.7)] were analyzed. On the single-leg decline squat, the VAS pain score reduced significantly in the patellar strap (14 mm, P = 0.04) and the sports tape condition (13 mm, P = 0.04), compared with control, but not placebo. A significant decrease in VAS pain during sports was found in the sports tape (7 mm, P = 0.04) and placebo group (6 mm, P = 0.04). The VAS pain score two hours after sports decreased significantly in the patellar strap, sports tape and placebo group (8-mm, P < 0.001, 10 mm, P = 0.001 and 7 mm, P = 0.03, respectively). This study's findings indicate that an orthosis (including placebo tape) during sports can reduce pain in PT patients in the short term.

Prospective Study of the Relation between Landing Biomechanics and Jumper's Knee.

The literature on the relation between jump biomechanics and jumper's knee indicates that a jump with horizontal displacement poses a threat for developing jumper's knee. Subjects with jumper's knee have been shown to display a stiff landing pattern characterized by a small range of motion. However, up to now only cross-sectional studies have been conducted. 6 teams from sports involving repetitive landing were followed prospectively for 2 years. At baseline athletes performed the Landing Error Scoring System jump and 3D kinematics and kinetics were obtained. A comparison was made between subjects who developed jumper's knee and those who did not develop it. 3 subjects developed jumper's knee during the study. Leg stiffness during landing was high compared to the mean of the healthy controls. No common kinematic patterns could be identified in these 3 subjects. The results suggest that athletes with high leg stiffness during landing might have an increased risk for developing jumper's knee, yet this conclusion is based on a very small sample. Subjects who develop jumper's knee do not show a common landing technique. Further research is needed to investigate whether leg stiffness can be used to identify athletes at risk and as a target variable to be used in prevention.

Risk factors for patellar tendinopathy in volleyball and basketball players: A survey-based prospective cohort study.

Patellar tendinopathy (PT) is a common overuse injury of the patellar tendon in jumping athletes. In a recent large cross-sectional study from 2008 several factors were identified that may be associated with the etiology of PT. However, because of the study design no conclusions could be drawn about causal relations. The primary aim of the current study is to investigate whether the factors identified in the previous 2008 study can also be prospectively recognized as predictors of symptomatic PT in 2011. Nine hundred twenty-six Dutch elite and non-elite basketball and volleyball players from the previous study were invited again to complete an online survey about knee complaints and risk factors for PT in 2011. The logistic regression included 385 athletes of which 51 (13%) developed PT since 2008. Male gender [odds ratio (OR) 2.0, 95% confidence interval (CI) 1.1-3.5] was found to be a risk factor for developing PT. No sports-related variables could be identified to increase the risk of developing PT, but some evidence was found for performing heavy physically demanding work, like being a nurse or a physical education teacher (OR 2.3, 95% CI 0.9-6.3). These findings indicate that, when considering preventive measures, it is important to take into account the total tendon load.

Jumper's knee or lander's knee? A systematic review of the relation between jump biomechanics and patellar tendinopathy.

Patellar tendinopathy (jumper's knee) is a common injury in sports that comprise jump actions. This article systematically reviews the literature examining the relation between patellar tendinopathy and take-off and landing kinematics in order to uncover risk factors and potential prevention strategies. A systematic search of the Pubmed, Embase and Amed databases was performed to identify studies that reported kinematics of sport specific jumps in relation to patellar tendinopathy. A quantitative analysis was performed on 4 indentified studies. Differences were found only between controls and asymptomatic subjects with patellar tendon abnormalities. Most differences were found during horizontal landing after forward acceleration. A synthesis of the literature suggests that horizontal landing poses the greatest threat for developing patellar tendinopathy. A stiff movement pattern with a small post-touchdown range of motion and short landing time is associated with the onset of patellar tendinopathy. Accordingly, employing a flexible landing pattern seems to be an expedient strategy for reducing the risk for (re-) developing patellar tendinopathy. Together, these findings indicate that improving kinetic chain functioning, performing eccentric exercises and changing landing patterns are potential tools for preventive and/or therapeutic purposes.

No difference in effectiveness between focused and radial shockwave therapy for treating patellar tendinopathy: a randomized controlled trial.

PURPOSE: The aim of the study was to compare the effectiveness of focused shockwave therapy (FSWT) and radial shockwave therapy (RSWT) for treating patellar tendinopathy. METHODS: Patients were randomized into two groups. One group received three sessions of FSWT, and the other group received three sessions of RSWT. Both groups also received an eccentric training programme. Follow-up measurements took place 1, 4, 7 and 14 weeks after the final shockwave treatment. The primary outcome measure was the Victorian Institute of Sport Assessment-Patella (VISA-P) questionnaire. Secondary outcome measures were pain during ADL, sports activities and the decline squat. RESULTS: Forty-three subjects (57 tendons) were included in the study. Twenty-one subjects (31 tendons) received FSWT, and 22 subjects (26 tendons) received RSWT. Both groups improved significantly on the VISA-P score, but there were no differences in improvement between the FSWT group (15 points on the VISA-P) and the RSWT group (9.6 points, n.s.). This was also the case for the secondary outcome measures. CONCLUSION: There were no statistically significant differences in effectiveness between FSWT and RSWT. It is therefore not possible to recommend one treatment over the other on grounds of outcome. Both groups improved significantly, although it is questionable whether this difference is clinically relevant. LEVEL OF EVIDENCE: II.

Treatment of task-specific dystonia in sports: A systematic review.

Introduction: Task specific dystonia is a movement disorder only affecting a highly practiced skill and is found in a broad set of expert movements including in sports. Despite affecting many sports, there is no comprehensive review of treatment options, which is in contrast to better studied forms of task specific dystonia in musicians and writers. For this reason, studies involving an intervention to treat task specific dystonia in sports were systematically reviewed, with special attention for the quality of outcome measures. Methods: The PICO systematic search strategy was employed on task-specific dystonia, and all synonyms. Inclusion criteria were peer reviewed published studies pertaining to sports, studies with a measurement and/or intervention in TSD, all in English. We excluded abstracts, expert opinions, narrative review articles, unpublished studies, dissertations and studies exclusively relating to choking. We included case reports, case studies and case-control studies. Results: In April 2022 Pubmed, Embase, Web of Science, and Psychinfo were searched. Of the 7000 articles identified, 31 were included that described psychological and invasive and/or pharmacological interventions. There was a lack of formal standardized outcome measures in studies resulting in low quality evidence for the effectiveness of treatment options. A descriptive synthesis showed emotional regulation was effective, but was exclusively tried in golfers. Interventions like botulinum toxin or pharmacology had a similar effectiveness compared to studies in musicians dystonia, however there was almost no formal evidence for these treatments. Conclusion: The quality of studies was low with a lack of standardized outcome measures. Future studies with larger cohorts and quantitative outcome measures are needed to improve understanding of treatments for task specific dystonia in athletes.

Do patients with chronic patellar tendinopathy have an altered somatosensory profile? A Quantitative Sensory Testing (QST) study.

The prevalence of tendinopathies in sports is high. The etiology and pain mechanisms of tendinopathies are not completely understood. Currently, little is known whether, or to which degree, somatosensory changes within the nervous system may contribute to the pain in tendinopathies. We conducted a patient controlled study in which we used the standardized QST protocol developed by the German Research Network on Neuropathic Pain. This protocol consists of seven different tests that measures 13 somatosensory parameters and can be seen as the gold standard to measure somatosensory function. Twelve athletes with clinically diagnosed chronic patellar tendinopathy (PT) mean duration 30 months (range 6-120) and 20 controls were included in the study. In two of the 13 QST parameters namely Mechanical Pain Threshold (P < 0.05) and Vibration Disappearance Threshold (P < 0.5) injured athletes were significantly more sensitive for the applied stimuli. None of the athletes had signs of Dynamic Mechanical Allodynia. Reduced mechanical pain thresholds or pinprick allodynia reflects the involvement of central sensitization upon the myelinated (Aδ-fibre) nociceptive input. From this explorative study, we conclude that sensitization may play a prominent role in the pain during and after sports activity in patella tendinopathy patients.

[Diagnosis and management of tendon problems]. / Diagnostiek en behandeling van peesproblemen.

Tendon problems of upper and lower extremity are common and can have impact on quality of life. The preferred terminology for load dependent tendon pain and loss of function is tendinopathy. The underlying pathophysiology of tendinopathy is complex and usually not a tendinitis. The Continuum of tendinopathy-model describes the role of load in 3 stages of tendinopathy which can be helpful in management of tendinopathy. Diagnosis of tendinopathy can be based on history and clinical examination. The role of imaging in diagnosis and prognosis is limited. Patient education, load management and progressive tendon loading exercises are the cornerstone of treatment. In case this approach fails there are several treatment options that can be considered, however there is only low or conflicting evidence on its effectiveness.

The JUMPFOOD study: additional effect of hydrolyzed collagen and vitamin C to exercise treatment for patellar tendinopathy (jumper's knee) in athletes-study protocol for a double-blind randomized controlled trial.

BACKGROUND: Patellar tendinopathy (PT) is a common problem in jumping athletes. Management can be challenging and treatment outcome is not always successful. In combination with tendon loading exercises, hydrolyzed collagen/vitamin C supplementation appears to have a promising effect on the recovery of tendinopathy. The aim of this study is to evaluate whether the use of oral supplementation of hydrolyzed collagen and vitamin C in combination with progressive tendon loading exercises (PTLE) is superior to PTLE and placebo on VISA-P score (which rates pain, function, sports participation) after 24 weeks for athletes with PT. METHODS: The JUMPFOOD study is a double-blinded, two-armed randomized controlled trial, in which the effectiveness of oral supplementation of hydrolyzed collagen/vitamin C combined with PTLE compared to PTLE with placebo on pain and recovery of function in athletes with PT will be investigated. Seventy-six athletes aged 16-40 years, with symptoms of PT for at least 12 weeks, who play sports at least once a week will be included. All participants will receive education, advice with regard to load management and a PTLE program according to the Dutch guidelines for anterior knee pain. In addition, the intervention group will receive daily 10 g hydrolyzed collagen and 40 mg vitamin C supplementation for 24 weeks whereas the control group receives 10 g maltodextrin placebo supplementation. Measurements will take place at baseline and at 12 and 24 weeks' follow-up. Primary outcome is the VISA-P score, which evaluates pain, function, and sports participation. For secondary outcome measures, data with regard to pain during functional tests, flexibility measurements, blood withdrawals, imaging characteristics of the tendon, and health questionnaires will be collected. During the follow-up period, participants will register sports participation, amount of training and tendon load, pain during sports, co-medication, and side-effects in a digital weekly diary. DISCUSSION: The JUMPFOOD study is the first large RCT to study the effectiveness of hydrolyzed collagen/vitamin C supplementation in combination with the PTLE program in athletes with patellar tendinopathy. If supplementation of collagen/vitamin C appears to be effective, this treatment can be implemented in daily sports medicine practice to improve the treatment outcome of patients with PT. TRIAL REGISTRATION: ClinicalTrials.gov NCT05407194. Registered on 7 June 2022.

Risk factors for patellar tendinopathy in basketball and volleyball players: a cross-sectional study.

Patellar tendinopathy (PT) has a multifactorial etiology, and many possible risk factors have been described in the literature. The findings are conflicting, though, and most research has been conducted on elite athletes. The aim of the current study is to determine the risk factors for PT in a large representative sample of basketball and volleyball players. Separate risk factors for men and women, basketball and volleyball players, and athletes with unilateral and bilateral PT were identified. All basketball and volleyball players between ages 18 and 35 from the Dutch Basketball Association and the Dutch Volleyball Association were invited to complete an online questionnaire on knee complaints and risk factors for PT. The logistic regression analyses included 2224 subjects. The risk factors for PT were age, playing at the national level, being male and playing volleyball (compared with playing basketball). The risk factors for men and women were comparable. Among volleyball players, outside hitters and middle blockers/hitters had an increased risk compared with setters. For basketball players, no risk factors could be identified. No differences in the risk factors were found between athletes with unilateral and bilateral PT. These findings should be taken into account for prevention and rehabilitation purposes.

In women with polycystic ovary syndrome and obesity, loss of intra-abdominal fat is associated with resumption of ovulation.

BACKGROUND: It is not clear why some anovulatory women with polycystic ovary syndrome (PCOS) and obesity resume ovulation and others remain anovulatory after weight loss. The objective of this study was to compare the changes in body fat distribution and specifically intra-abdominal fat (IAF) and subcutaneous abdominal fat (SAF) between a group of anovulatory women with PCOS and obesity who resume ovulation (RO+) to those who remain anovulatory (RO-) during a lifestyle program. METHODS: In a prospective pilot cohort study, anovulatory women with PCOS underwent a 6 month lifestyle program in a tertiary fertility clinic. Body fat distribution was assessed by anthropometrics, dual-energy X-ray absorptiometry (DEXA) and single slice abdominal CT scan at intake, after 3 months and after 6 months. Baseline-corrected changes over time were analysed using generalized estimating equations longitudinal regression analysis. RESULTS: In 32 anovulatory women with PCOS (age, 28 ± 4 years; BMI, 37.5 ± 5.0 kg/m²), there were no significant baseline differences in anthropometrics and biochemical assessment between 14 RO+ participants and 18 RO- participants. RO+ women lost more weight (6.3 versus 3.0%) and abdominal fat on DEXA (15.0 versus 4.3%) compared with RO- women. Resumption of ovulation was associated with early and consistent loss of IAF (12.4 versus 5.0% at 3 months and 18.5 versus 8.6% at 6 months). Loss of SAF between the RO+ women and the RO- women was similar at 3 months (6.2 versus 6.1%) but did not change any further in RO- women (6.1%) as it did in RO+ women (11.4%) at 6 months. CONCLUSIONS: In anovulatory women with PCOS and obesity undergoing a lifestyle program, RO+ women lose more body weight and abdominal fat on DEXA than RO- women. In addition, this study shows that early and consistent loss of IAF is associated with resumption of ovulation. Future studies should address the mechanisms behind these changes and should assess interventions aimed at loss of IAF to facilitate resumption of ovulation.

[Preventing anterior cruciate ligament injury in children is effective]. / Preventie van voorste-kruisbandletsels bij kinderen.

An anterior cruciate ligament (ACL) injury in children is a devastating injury. After an ACL injury 1 in 3 children obtain a second injury of the ipsilateral or contralateral ACL. Children who suffer an ACL injury also have a ten times higher risk of osteoarthritis. Preventative training programmes can decrease the risk of acute knee injuries in young sportspeople; however, implementation of these prevention programmes is challenging, so it is important to inform associations, clubs, youth trainers and parents about the added value of these programmes. Children with ACL injuries must receive specialized guidance during rehabilitation, regardless of whether they have been treated conservatively or surgically. Because of the risk of a second ACL injury,we recommend that children should not to return to pivoting sports until at least 12 months after surgery for ACL.

Extracorporeal shockwave therapy for patellar tendinopathy: a review of the literature.

BACKGROUND AND PURPOSE: Extracorporeal shockwave therapy (EWST) has become a popular treatment for patellar tendinopathy. The purpose of this review was to study the effectiveness of ESWT treatment for patellar tendinopathy; to draft guidelines for an effective treatment protocol of ESWT treatment; and to identify topics for further research. METHODS: A computerised search of the Medline and Embase databases was conducted on 1 August 2007, to identify studies dealing with the effectiveness of ESWT for patellar tendinopathy. RESULTS: Seven articles describing the effectiveness of ESWT on patellar tendinopathy, all published after 2000, were included. These studies included a total of 283 patients (298 tendons), 204 of whom (215 tendons) were assigned to ESWT treatment. The treatment results were positive but most studies had methodological deficiencies, small numbers and/or short follow-up periods. Method of application and shockwave generation, energy level, number and frequency of treatments, use of (local) anaesthesia and method of localisation were variable. CONCLUSION: ESWT seems to be a safe and promising treatment for patellar tendinopathy with a positive effect on pain and function. Based on current knowledge it is impossible to recommend a specific treatment protocol. Further basic and clinical research into the working mechanism and effectiveness of ESWT for patellar tendinopathy are necessary.

[Symptoms of sleepiness and vomiting in an open-water swimmer]. / Slaperigheid en braken bij een openwaterzwemmer.

Long-distance open-water swimming is a swimming discipline which takes place in outdoor bodies of water, such as open oceans, lakes and rivers. The activity has grown in popularity. This case report describes the attempt of an Olympic Champion (Maarten van der Weijden) to swim 200 km along a route taking him to eleven Frisian cities. We describe the importance of good preparation and training but also the health problems open-water swimmers, and (medical) staff, might encounter during such an extreme event. Optimal endurance, management of dizziness and hypothermia, high caloric food intake, risk of (gastrointestinal) infections and lack of sleep are all important factors to take into account in long-distance open-water swimming.

Are the take-off and landing phase dynamics of the volleyball spike jump related to patellar tendinopathy?

OBJECTIVE: The causal mechanism of the chronic sports injury patellar tendinopathy is not well understood. The aim of the present study was to compare ankle and knee joint dynamics during the performance of the volleyball spike jump between healthy volleyball players (n = 8) and asymptomatic volleyball players with previous patellar tendinopathy (n = 7). DESIGN: Cross-sectional. METHODS: Inverse dynamics were used to estimate ankle and knee joint dynamics. From these multiple biomechanical variables, a logistic regression was performed to estimate the probability of the presence or absence of previous patellar tendinopathy among the volleyball players studied. RESULTS: Several biomechanical variables improved the prediction of the presence or absence of previous patellar tendinopathy. For landing, ankle plantar flexion at the time of touch-down, and knee range of motion during the first part of impact, and for take-off, loading rate of the knee extensor moment during the eccentric countermovement phase of take-off were predictive. As interaction effects, the presence or absence of previous patellar tendinopathy were correctly predicted by ankle and knee range of motion during the first part of impact, by loading rate of the knee extensor moment during the eccentric phases of take-off and landing, and by knee angular velocity during the eccentric phases of take-off and landing. CONCLUSION: Smaller joint flexion during the first part of landing impact , and higher rate of knee moment development during the eccentric phases of the spike-jump landing sequence, together with higher knee angular velocities, might be risk factors in the development of patellar tendinopathy in volleyball players.

[Patellar tendinopathy ('jumper's knee'); a common and difficult-to-treat sports injury]. / Patellatendinopathie ('jumper's knee'); een veelvoorkomende en lastig te behandelen sportblessure.

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. Prolonged rehabilitation is necessary because of slow tendon recovery. Anti-inflammatory treatment is often unsuccessful. Surgery does not guarantee a quick symptom-free return to sport at the original level either. Extracorporeal shock wave therapy, ultrasound-guided sclerosing of new vessels and tendinous and peritendinous injections of aprotinin and autologous growth factors seem to be promising new treatment options.

[The value of preventive advice and examination focusing on cardiovascular events and injury for novice runners]. / De waarde van preventieve adviezen en keuringen bij beginnende hardlopers met het oog op cardiovasculaire gebeurtenissen en blessures.

Novice runners often seek advice from a physician about training responsibly. Common concerns include sudden cardiac arrest, advice on running injuries and how to avoid these events. Cardiologic screening and ergometry are only beneficial if the athlete has a high-risk profile. In the world of running, there are many myths regarding the prevention ofinjuries. Many recommendations on the use of running shoes, supportive insoles, running on soft or hard surfaces and the value of stretching have been made based on empirical evidence. The actual effects of these recommendations on injury prevention, however, have not been evaluated sufficiently. The value of preventive examination of structural and locomotor elements is also unclear at this time. Progression of training load in which the duration and intensity of training increases by less than 10% per week, appears to be the most reasonable way to prevent running injuries.