CHANGE IN FOOTSTRIKE POSITION IS RELATED TO ALTERATIONS IN RUNNING ECONOMY IN TRIATHLETES

Biomechanical factors are likely related to the impairment in running economy frequently observed in triathletes when running after cycling (Millet et al., 2000). Cycling has been shown to interfere with muscle recruitment during subsequent running in some highly-trained triathletes (Chapman et al., 2008), but the implications of this on run performance are unknown. Links between muscle recruitment and running economy have been established during isolated running (Paavolainen et al., 1999), which compel the proposition that any change in muscle recruitment following cycling might be associated with running economy. Stride frequency, stride length and hip and knee angles have been reported to be unchanged after cycling (Quigley & Richards, 1996; Hue et al., 1997), however, muscle recruitment and limb movement have not been simultaneously measured in previous studies that have investigated the relationship between biomechanical factors and running economy after cycling. The purpose of the current investigation was to evaluate changes in neuromuscular control (muscle and movement control) during running after a 45 min high-intensity cycle and their relationships to alterations in running economy

SHORT-TERM PLYOMETRIC TRAINING IMPROVES ALTERED NEUROMOTOR CONTROL DURING RUNNING AFTER CYCLING IN TRIATHLETES

Cycling has a direct negative effect on some highly-trained triathletes’ ability to execute optimal neuromotor strategies specific to running (Chapman et al., 2008). The presence of altered neuromotor control when running off-the-bike has been associated with exercise-related leg pain (Chapman et al., 2010). Accordingly, identification of training interventions that could minimise this interference may aid in prevention of injury and augmentation of performance during running following cycling. Plyometric training is a specific form of strength training that has been reported to improve running economy by enhancing neuromuscular function (Paavolainen et al., 1999). The primary aim of this study was to examine the effect of plyometric training on triathletes neuromotor control and running economy in those in which neuromotor control is aberrant during running after cycling

A prospective investigation of changes in the sensorimotor system following sports concussion. An exploratory study

Background Sports concussion is a risk for players involved in high impact, collision sports. Post-concussion, the majority of symptoms subside within 7–10 days, but can persist in 10–20% of athletes. Understanding the effects of sports concussion on sensorimotor systems could inform physiotherapy treatment. Objective To explore changes in sensorimotor function in the acute phase following sports concussion. Design Prospective cohort study. Methods Fifty-four players from elite rugby union and league teams were assessed at the start of the playing season. Players who sustained a concussion were assessed three to five days later. Measures included assessments of balance (sway velocity), vestibular system function (vestibular ocular reflex gain; right-left asymmetry), cervical proprioception (joint position error) and trunk muscle size and function. Results During the playing season, 14 post-concussion assessments were performed within 3–5 days of injury. Significantly decreased sway velocity and increased size/contraction of trunk muscles, were identified. Whilst not significant overall, large inter-individual variation of test results for cervical proprioception and the vestibular system was observed. Limitations The number of players who sustained a concussion was not large, but numbers were comparable with other studies in this field. There was missing baseline data for vestibular and cervical proprioception testing for some players. Conclusions Preliminary findings post-concussion suggest an altered balance strategy and trunk muscle control with splinting/over-holding requiring consideration as part of the development of appropriate physiotherapy management strategies

HAPPi Kneecaps! Protocol for a participant- and assessor-blinded, randomised, parallel group feasibility trial of foot orthoses for adolescents with patellofemoral pain

BACKGROUND: Patellofemoral pain (PFP) is a common cause of knee pain in adolescents, but there are limited evidence-based treatment options for this population. Foot orthoses can improve pain and function in adults with PFP, and may be effective for adolescents. The primary aim of th

Tibialis posterior in health and disease: a review of structure and function with specific reference to electromyographic studies

Tibialis posterior has a vital role during gait as the primary dynamic stabiliser of the medial longitudinal arch; however, the muscle and tendon are prone to dysfunction with several conditions. We present an overview of tibialis posterior muscle and tendon anatomy with images from cadaveric work on fresh frozen limbs and a review of current evidence that define normal and abnormal tibialis posterior muscle activation during gait. A video is available that demonstrates ultrasound guided intra-muscular insertion techniques for tibialis posterior electromyography

A pilot study of the initial effects of anti-pronation taping on electromyographic activity of lower leg muscles during walking

Clinicians frequently use anti-pronation (AP) taping to relieve symptoms and improve function in the management of musculoskeletal pain and injury, yet the mechanisms behind this effect have not been fully explored. To date, the majority of the literature has focused on the mechanical effects of AP taping and little has been done to explore its possible neurophysiological effects. This pilot study set out to investigate the effect of the Augmented LowDye taping technique on the electromyographic (EMG) activity of muscles of the lower leg during walking. Five asymptomatic subjects, who exhibited clinically abnormal pronation during a visual assessment of gait, walked on a treadmill for ten minutes before and after the application of the taping technique. Bipolar intra-muscular electrodes were used to record the EMG of the tibialis anterior (TA), tibialis posterior (TP), gastrocnemius (GN) and peroneus longus (PL) during walking. A two-way repeated measures analysis of variance was used to compare the EMG activity (peak amplitudes, duration of activity) for each muscle. The co-efficient of multiple correlations was calculated to evaluate the variability of muscle recruitment patterns within each subject. Visual comparisons of EMG activity during individual walking strides before and after the application of tape were also performed. Peak EMG activity decreased by 25% in TA and by 45% in TP following the application of tape. There were no significant differences in peak EMG activity of GN or PL, or in duration of EMG activity for any muscle. Results from this study suggest that neurophysiological changes could contribute to the mechanism behind AP taping