Astrid de Vries

The effect of a patellar strap on knee joint proprioception in healthy participants and athletes with patellar tendinopathy

OBJECTIVES The primary aim of this study is to investigate the effect of the use of a patellar strap on knee joint proprioception in both healthy participants and in patients with patellar tendinopathy (PT). Secondary aims are to examine whether there is a difference in effectiveness of the use of a patellar strap between participants with low and high proprioceptive acuity and if possible predictors of effectiveness can be determined. DESIGN Case-control. METHODS The threshold to detect passive motion with and without a patellar strap was assessed in 22 healthy participants and 21 unilateral PT patients. RESULTS The results from the mixed model analysis show that in both groups of participants a small but statistically significant improvement in proprioception was found, primarily in those who had low proprioceptive acuity. A notable finding was that in the symptomatic leg of the PT group no improvement in proprioception by wearing a strap could be determined. Male gender and having fewer symptoms were possible predictors of effectiveness in PT patients. CONCLUSIONS As proprioception plays a role in optimising movements and reducing load to joint-related structures like tendons and ligaments, it is considered an important protection mechanism. Although the improvements in proprioception as a result of wearing the strap are small, it might be that the use of a patellar strap can potentially play a role in injury prevention since poor proprioception can be a risk factor for (re)-injury.

Effect of patellar strap and sports tape on pain in patellar tendinopathy

Numerous athletes with patellar tendinopathy (PT) use a patellar strap or sports tape during sports. This studys 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 studys findings indicate that an orthosis (including placebo tape) during sports can reduce pain in PT patients in the short term.

The impact of patellar tendinopathy on sports and work performance in active athletes

ABSTRACT Greater insight into sports and work performance of athletes with patellar tendinopathy (PT) will help establish the severity of this common overuse injury. Primary aim of this study is to investigate the impact of PT on sports and work performance. Seventy seven active athletes with PT (50 males; age 28.1 ± 8.2 years; Victorian Institute of Sports Assessment Patella 56.4 ± 12.3) participated in this survey. Sports performance, work ability and work productivity were assessed using the Oslo Sports Trauma Research Center overuse injury questionnaire, the single-item Work Ability Index and the Quantity and Quality questionnaire, respectively. Reduced sports performance was reported by 55% of the participants; 16% reported reduced work ability and 36% decreased work productivity, with 23% and 58%, respectively, for physically demanding work. This study shows that the impact of PT on sports and work performance is substantial and stresses the importance of developing preventive measures.

Effect of patellar strap and sports tape on jumper's knee symptoms: protocol of a randomised controlled trial

INTRODUCTION Patellar straps or sports tapes are commonly used by athletes with patellar tendinopathy in order to reduce pain and to continue sports participation. Currently, there is no scientific evidence for the effectiveness of a patellar strap or sports tape in the management of this common injury. AIM To investigate the effect of the use of a patellar strap and sports tape on pain and sports participation in subjects with patellar tendinopathy. DESIGN The study is divided into two parts: a randomised controlled crossover experiment and a randomised controlled trial (parallel group design). PARTICIPANTS AND SETTING 140 patients diagnosed with patellar tendinopathy recruited from sports medical centres and physiotherapist practices. INTERVENTION In the first part of the study, participants serve as their own control by performing three functional tests under four different conditions (patellar strap, sports tape, placebo tape, and no orthosis). In the second part, participants keep a log for two weeks (control week and intervention week) about the pain experienced during and after sports and their level of sports participation. In the intervention week participants will use the orthosis assigned to them during training and competition. MEASUREMENTS The amount of pain (both parts of the study) and sports participation (second part only) will be measured. ANALYSIS To analyse the effects of the orthoses a Linear Mixed Model will be used. DISCUSSION The knowledge gained in this study can be used by practitioners in their advice for athletes with patellar tendinopathy about using patellar strap and sports tape during sports.

Effect of a patellar strap on the joint position sense of the symptomatic knee in athletes with patellar tendinopathy

OBJECTIVES The primary aim of this study was to investigate the effect of a patellar strap on the proprioception of the symptomatic leg in PT. Secondary aims were to investigate a possible difference in effectiveness between athletes with high and low proprioceptive acuity, and whether predictors of effectiveness could be found. DESIGN Randomised cross-over pilot study. METHODS 24 athletes with PT (age 27.3±9.0, VISA-P 50.6±11.2) performed a joint position sense test with and without a patellar strap. The difference between both conditions was analysed using linear mixed-model analysis. RESULTS No improvement in the joint position sense using the strap for the whole group was found, while those classified as having low proprioceptive acuity did improve using the strap (p=0.015, 17.2%). A larger knee girth, longer duration of symptoms and more tendon abnormalities were negatively associated with the straps effectiveness. CONCLUSIONS The use of a patellar strap improves the knee joint proprioception - measured with joint position sense - of the symptomatic leg in athletes with poor proprioceptive acuity. Especially athletes with relatively small knee girth, short duration of symptoms and small tendon abnormalities might benefit from the strap. As proprioception plays an important role in motor control, and deficits in proprioception may put an athlete at risk for (re-)injury, these findings may be relevant for prevention as well as rehabilitation purposes in those PT athletes with low proprioceptive acuity.

26 Risk Factors For Patellar Tendinopathy: A Survey- Based Prospective Cohort Study

Introduction Patellar tendinopathy (PT) is a painful, sports related overuse injury of the patellar tendon3 with a high prevalence in sports that require a lot of jumping and landing, like volleyball and basketball.4 Since PT can be very persistent and treatments do not guarantee recovery1 it is important to identify risk factors for this injury that can be used for prevention. In 2008 in a cross-sectional study the following factors were identified that may be associated with the aetiology of PT: younger age, playing national, being male and playing volleyball (compared to playing basketball).2 However, due to the retrospective design of this study, nothing could be concluded about causal relations. The aim of the current study is to investigate if the factors identified in the previous study can also be prospectively recognised as predictors of symptomatic PT three years later. Methods 926 asymptomatic Dutch non-elite and elite basketball and volleyball players who participated in the retrospective 2008-study were invited to complete again an online survey in 2011. Questions about respondent characteristics, sports participation, knee injuries and occupation were included in the survey. Diagnosis of PT was based on a self reported pain map and/or made by a physical therapists or physician. Using simple and multiple logistic regression analysis, it was investigated if variables from the 2008-survey could be identified as predictors of PT in 2011. Results 385 athletes (290 volleyball and 90 basketball players) completed the questionnaire in 2011 and 51 (13%) of these participants developed PT since 2008 (18% male and 10% female). In the simple logistic regression analysis we found in the total group that males had increased odds to develop PT (OR 2.0 95% CI 1.1–3.5), this was also found in the volleyball players separately (OR 2.6 95% CI 1.3–5.2). In the volleyball players a trend was found for increased odds for those jumping at work (OR 2.4 95% CI 1.0–5.5) compared to not jumping at work and for those performing heavy physically demanding work compared to mentally demanding work (OR 2.6 95% CI 0.9–7.8), the latter variable showing also a trend in the total group in the multiple logistic regression analysis (OR 2.3 95% CI 0.9–6.3). In the basketball population we found a trend toward increased odds for a higher BMI as a risk factor for developing PT in the simple regression analysis (OR 1.2 95% CI 1.0–1.5). Discussion In this first prospective cohort study investigating risk factors for symptomatic PT in a large group of non-elite and elite basketball and volleyball players it was shown that the most important factors were male gender and performing physically demanding work (whether or not involving jumping). There was some evidence in the relative small group of basketball players that a higher BMI increases the risk for PT. In contrast to the study of Van der Worp et al (2012), no specific sports related factors for PT were identified in this study. This can be caused by the smaller number of participants in this study and/or it might be that other sports-related factors that cannot be measured with an online survey (like jumping height or landing strategy) have more predictive power. Implications for practice The findings from this study suggest that especially in males (with higher BMI) the activities at work should be taken into account when adjusting patellar tendon load for PT prevention purposes. References 1 Gaida and Cook. Current Sports Medicine Reports. 2011;10:255–270 2 van der Worp, et al. Scand J Med Sci Sports. 2012;22:783–790 3 Warden, Brukner. Clin Sports Med. 2003;22:743–759 4 Zwerver, et al. Am J Sports Med. 2011;39:1984–1988

25 Effect Of The Use Of Patellar Strap And Sports Tape On Pain In Patellar Tendinopathy

Introduction Numerous athletes with patellar tendinopathy (PT) use a patellar strap or sports tape during sports aiming to reduce their pain. Despite that theories are suggested about the working mechanisms of these orthoses,2 there is to our knowledge no scientific evidence supporting the use of these orthoses in this common overuse injury. The aim of this study was to investigate the effect of wearing a patellar strap or sports tape on pain in athletes with PT. The secondary aim was to investigate if specific patients’ characteristics are related to the effectiveness of the orthoses. Methods In a randomised controlled crossover experiment, active athletes with clinically diagnosed PT were included. All participants performed three functional patellar tendon loading tests (single leg decline squat (1x and 10x), counter movement jump (both legs and one leg) and triple hop test) under four different conditions: control, patellar strap, sports tape, and placebo (kinesiotape administered in a non-functional way). The order of the conditions was randomised and balanced between subjects. A visual analogue scale (VAS, 0–100 mm) for pain was used to quantify the amount of pain experienced by the subjects during the tests. A difference of 12 mm was considered clinically relevant.1 A mixed model analysis and a linear regression analysis were used for the data analysis. The study design was previously published.4 Results A total of 97 athletes from different sports (61% male, age 27.0 y (SD 8.1), VISA-P 58.5 (SD 12.7)) were analysed. On the 10x single leg decline squat we found a significant (p < 0.05) median reduction of 14 mm and 13 mm on the VAS pain score in the patellar strap and sports tape condition, compared to control. A reduction of 7 mm and 6 mm compared to placebo was found (p = 0.33 and p = 0.32). A reduction of 11.5 mm (p = 0.06) was found in the patellar strap condition compared to control during the one legged counter movement jump. Females seem to benefit more from wearing sports tape compared to men. No predictors could be identified for the effectiveness of a patellar strap. Abstract 25 Figure 1 VAS score for the four conditions during the 10x single leg decline squat (white bars) and the one legged counter movement jump (black bars) Discussion This study shows that in athletes with PT the use of a patellar strap or sports tape results in significant and clinically relevant (>12 mm) lower VAS pain scores during functional tests with high patellar tendon load like the 10 times single leg decline squat. Part of the effect can be a placebo effect, as the placebo condition also caused a reduction in the VAS pain score compared to control. Females seem to benefit more than men from the use of sports tape. As in the current study only the short term effect of the orthoses was investigated, future research should focus on long term effects as these might be different.3 Furthermore, it is very interesting to investigate if the same effects of the orthoses will be found in a sports specific situation and to determine if other factors can predict the effectiveness of wearing orthoses in order to be able to provide the athlete with an evidence based advice on the use of orthoses in PT. References 1 Kelly. Emergency Medicine Journal. 2001;18: 205–207 2 Lavagnino et al. Sports Health: A Multidisciplinary Approach. 2011;3:296–302 3 Öken et al. Journal of Hand Therapy. 2008;21:63–68 4 Vries de et al. Journal of Physiotherapy. 2013;59:270