Gert-Jan Pepping

Risk factors for patellar tendinopathy: a systematic review of the literature

Patellar tendinopathy (PT) is an injury with a high prevalence in sports. Knowledge of risk factors is essential for developing preventive measures and rehabilitation programmes. However, risk factors associated with PT have not yet been systematically studied. This review was undertaken to identify risk factors associated with PT. The literature was systematically searched to identify articles that investigated risk factors for PT. There was no strong or moderate evidence that any investigated risk factor was associated with PT. For nine risk factors there was some evidence: weight, body mass index, waist-to-hip ratio, leg-length difference, arch height of the foot, quadriceps flexibility, hamstring flexibility, quadriceps strength and vertical jump performance. Based on the present evidence, reducing body weight, increasing upper-leg flexibility and quadriceps strength and the use of orthotics may be beneficial treatment options. However, it should be stressed that the evidence for the nine identified risk factors was only limited. Therefore, there is a clear need for high-quality studies in order to identify the exact risk factors associated with PT.

No Effect of a Graded Training Program on the Number of Running-Related Injuries in Novice Runners: A Randomized Controlled Trial

Background Although running has positive effects on health and fitness, the incidence of a running-related injury (RRI) is high. Research on prevention of RRI is scarce; to date, no studies have involved novice runners. Hypothesis A graded training program for novice runners will lead to a decrease in the absolute number of RRIs compared with a standard training program. Study Design Randomized controlled trial; Level of evidence, 1. Methods GRONORUN (Groningen Novice Running) is a 2-armed randomized controlled trial comparing a standard 8-week training program (control group) and an adapted, graded, 13-week training program (intervention group), on the risk of sustaining an RRI. Participants were novice runners (N = 532) preparing for a recreational 4-mile (6.7-km) running event. The graded 13-week training program was based on the 10% training rule. Both groups registered information on running characteristics and RRI using an Internet-based running log. The primary outcome measure was RRIs per 100 participants. An RRI was defined as any musculoskeletal complaint of the lower extremity or back causing a restriction of running for at least 1 week. Results The graded training program was not preventive for sustaining an RRI (χ 2 = 0.016, df = 1, P = .90). The incidence of RRI was 20.8% in the graded training program group and 20.3% in the standard training program group. Conclusions This randomized controlled trial showed no effect of a graded training program (13 weeks) in novice runners, applying the 10% rule, on the incidence of RRI compared with a standard 8-week training program.

Pacing and decision making in sport and exercise : The roles of perception and action in the regulation of exercise intensity

In pursuit of optimal performance, athletes and physical exercisers alike have to make decisions about how and when to invest their energy. The process of pacing has been associated with the goal-directed regulation of exercise intensity across an exercise bout. The current review explores divergent views on understanding underlying mechanisms of decision making in pacing. Current pacing literature provides a wide range of aspects that might be involved in the determination of an athlete’s pacing strategy, but lacks in explaining how perception and action are coupled in establishing behaviour. In contrast, decision-making literature rooted in the understanding that perception and action are coupled provides refreshing perspectives on explaining the mechanisms that underlie natural interactive behaviour. Contrary to the assumption of behaviour that is managed by a higher-order governor that passively constructs internal representations of the world, an ecological approach is considered. According to this approach, knowledge is rooted in the direct experience of meaningful environmental objects and events in individual environmental processes. To assist a neuropsychological explanation of decision making in exercise regulation, the relevance of the affordance competition hypothesis is explored. By considering pacing as a behavioural expression of continuous decision making, new insights on underlying mechanisms in pacing and optimal performance can be developed.

Emotional contagion in soccer penalty shootouts: Celebration of individual success is associated with ultimate team success

Abstract We examined the association between celebratory responses after successful soccer penalty kicks and the outcome of a penalty shootout. Individually displayed post-shot behaviours in penalty shootouts held in World Cups and European Championships (N = 151) were rated on the presence of universally distinct and recognizable behaviours associated with positive emotions. Using chi-square analyses we investigated which behaviours were associated with winning the shootout, when the relative standing between the teams was equal. Players who engaged in certain celebratory post-shot behaviours were more likely to be in the team that ultimately won the penalty shootout. In particular, celebrations including both arms were associated with winning the shootout. It was more likely that the next kick taken by an opponent was missed after a player displayed these behaviours after a goal than when he did not. The findings are interpreted in terms of emotional contagion – that is, the transference of emotions from individuals onto teammates and opponents. It is suggested that the individual expression of post-performance emotions serves a direct purpose in enhancing future team performance and that emotional contagion is an important process in the context of elite sport performance.

Participation in sports by lower limb amputees in the Province of Drenthe, The Netherlands

The numbers of lower limb amputees participating in recreational activity date back more than 25 years. Previous studies have shown that 60% of lower limb amputees participated in recreational activities, including sports. To date, research in The Netherlands into sports participation of this specific amputee population is insufficient. The purpose of the reported survey was to investigate the sports participation habits of lower limb amputees in the Province of Drenthe, The Netherlands, using a self-constructed questionnaire. A total of 105 lower limb amputees responded (36%), a large proportion of whom were traumatic amputees (31%). Of the respondents, 34 (32%) participated in some form of sport. Results indicated that participation in sport before the amputation was a predetermining factor for amputees to participate in sports whilst the level of amputation, age and etiology were not predetermining factors of participation in sports after a lower limb amputation.

Self-regulation of practice behavior among elite youth soccer players: an exploratory observation study.

This study aimed to measure behavioral correlates of self-regulation in elite youth soccer players. Behaviors regarded as indicative of self-regulated learning were identified by interviewing six expert youth soccer coaches. These behaviors were observed during practice of eight elite youth soccer players aged 15–17 years, and linked with self-reported self-regulated learning scores to describe behavioral correlates of self-regulation. Results indicated that self-regulated learning is reflected in taking responsibility for learning and that players’ practice environment plays a significant role. This study highlights the importance of measuring overt behavior to gain a complete impression of youth soccer players’ self-regulated learning skills.

Patient guided Piezo-electric Extracorporeal Shockwave Therapy as treatment for chronic severe patellar tendinopathy : A pilot study

BACKGROUND AND PURPOSE Patellar tendinopathy is a common overuse injury for which no evidence-based treatment guidelines exist. Extracorporeal Shock Wave Therapy (ESWT) seems to be an effective treatment for patellar tendinopathy but the most beneficial treatment strategies still need to be ascertained. Aim of this pilot study was to investigate if patient guided Piezo-electric, focused ESWT, without local anesthesia is a safe and well tolerated treatment which improves pain and function in patients with patellar tendinopathy. METHODS Nineteen male athletes with severe chronic patellar tendinopathy received 3 patient guided focused medium to high energy ESWT treatments at a weekly interval. Before and after 3 months VISA-P and VAS (pain) scores were recorded. Data on side effects and complications of treatment were also collected. RESULTS No serious complications were reported and patients tolerated the treatment well. Mean VISA-P score improved from 36.1 to 50.1 (p < 0.05), VAS decreased from to 7.2 to 3.7 (p < 0.05). CONCLUSION Patient guided Piezo-electric ESWT without local anesthesia is a safe and well tolerated treatment which should be considered as a treatment for patients with patellar tendinopathy.

TauG-guidance of transients in expressive musical performance.

The sounds in expressive musical performance, and the movements that produce them, offer insight into temporal patterns in the brain that generate expression. To gain understanding of these brain patterns, we analyzed two types of transient sounds, and the movements that produced them, during a vocal duet and a bass solo. The transient sounds studied were inter-tone f0(t)-glides (the continuous change in fundamental frequency, f0(t), when gliding from one tone to the next), and attack intensity-glides (the continuous rise in sound intensity when attacking, or initiating, a tone). The temporal patterns of the inter-tone f0(t)-glides and attack intensity-glides, and of the movements producing them, all conformed to the mathematical function, τG(t) (called tauG), predicted by General Tau Theory, and assumed to be generated in the brain. The values of the parameters of the τG(t) function were modulated by the performers when they modulated musical expression. Thus the τG(t) function appears to be a fundamental of brain activity entailed in the generation of expressive temporal patterns of movement and sound.

Effects of Affordance Perception on the Initiation and Actualization of Action

Studies have shown information specifying some affordances may be faster or easier to perceive than others. This article investigates the effect of affordance perception on the time taken to initiate and perform an action. In particular it focuses on how action timing varies as a function of a continuum of afforded action, that is, around an action-boundary. In Experiment 1, participants made judgments regarding whether they could fit a small ball through a series of different size apertures. Judgments were quick and accurate at the extremes of the affordance scale; however, at the perceived action-boundary longer, more variable initiation times (ITs) were observed. Trials repeated over 3 consecutive days revealed a systematic change in the IT distribution and demonstrated that IT is highly sensitive to changes in location of the perceived action-boundary. In Experiment 2 effects of action-scaling were observed on IT and movement time of afforded actions: around the perceived action-boundary the afforded action took longer to be both perceived and acted upon. The results highlight that affordance perception influences not only action selection and preparation but also the action itself. The findings are discussed in terms of the informational basis of action responses.

Sex differences and action scaling in overhead reaching.

Specifications of affordances is independent of the anthropometric scale of the perceiver. It is therefore predicted that sex differences disappear when perceptual performance is scaled relative to the relevant physical properties of the system formed by performer and environment in a particular action. 24 women and 30 men were compared for their ability to perceive the boundaries for overhead reaching for a ball suspended above them. Perceived and actual maximum action boundaries were measured in two height conditions, with and without wearing 15-cm high blocks under their feet. On average the men reached higher than the women; however, when perceived maximum reachable height was expressed as a ratio of actual maximum reachable height, the difference between the groups disappeared. The participants showed an identical fit between environment and performer in both height conditions. The results indicate that the specification of affordances for overhead reaching is independent of the height and the sex of the performer.