Biomechanical and Physical Characteristics of Whitewater Kayakers with and without Shoulder Pain

Participation in whitewater kayaking is growing faster than any other outdoor recreational pursuit. With increases in participation, an increase in the number of injuries associated with whitewater kayaking may also become apparent. Overuse injuries are the most prevalent type of injury found in whitewater kayakers. Due the large range of motion and forces that occur through the shoulder while kayaking, the most common injury location is the shoulder. Little scientific inquiry has been performed assessing the kinematics of kayaking and the musculoskeletal attributes of these athletes. Sixteen whitewater kayakers with shoulder pain and sixteen whitewater kayakers without shoulder pain participated in this study. Each subject underwent kinematic and electromyographic analysis of the forward kayak stroke. Additionally, participants underwent clinical examination of shoulder injury, clinical assessment of shoulder and torso range of motion, posterior shoulder tightness assessment, isokinetic strength testing at the shoulder, and a scapular kinematic evaluation during a standardized humeral elevation task.The most common type of injury found was related to overuse. Statistical comparisons occurred between the involved and uninvolved limb in the shoulder pain group and between the involved and uninvolved and matching shoulders in the control group, respectively. Significant differences were found between in involved and uninvolved shoulder for shoulder internal rotation and abduction range of motion. Additional differences were found for these variables between the involved shoulder in the pain group and the matching shoulder in the control group. Kayakers with shoulder pain present with decreased shoulder range of motion on their involved shoulder. Assessment of the specific types of injuries seen in whitewater kayakers should be further evaluated. Additionally, the role of increasing range of motion through injury prevention programs in whitewater kayakers with shoulder pain should be investigated

Effects of Lower Extremity Aerobic Exercise and Conditioned Pain Modulation on Evoked Shoulder Pain

Background: Emerging evidence suggests that aerobic exercise and conditioned pain modulation may be advocated in treating patients with musculoskeletal pain. The effects of lower extremity aerobic exercise and conditioned pain modulation on evoked shoulder pain are not known. Purpose: To determine the acute effects of lower extremity aerobic exercise and conditioned pain modulation on outcomes of evoked shoulder pain from pain pressure threshold measurements. Study Design: Repeated measures. Methods: Thirty (30) healthy volunteers were tested over the course of two sessions. Session 1 consisted of collecting pain pressure threshold measurements over the infraspinatus before and immediately following a conditioned pain modulation with cool water. Session 2 consisted of collecting pain pressure threshold measurements over the infraspinatus before and immediately following a bout of lower extremity aerobic exercise on a recumbent stepper apparatus. Results: Pain pressure threshold was not significantly influenced by the conditioned pain modulation using cool water (p=0.725). Pain pressure threshold was significantly increased immediately following the lower extremity exercise session (P\u3c0.001). Conclusion: Conditioned pain modulation with cool water did not produce any significant changes in pain pressure threshold. Lower extremity aerobic exercise acutely increased pain pressure threshold in participants with experimentally induced shoulder pain. Physical therapists may consider lower extremity aerobic exercise to produce short-term hypoalgesic effects and facilitate the application of more active interventions

Acute rotator cuff tendinopathy: does ice, low load isometric exercise, or a combination of the two produce an analgaesic effect?

This document is the Accepted Manuscript version of the following article: Parle PJ, Riddiford-Harland DL, Howitt CD, et al. 'Acute rotator cuff tendinopathy: does ice, low load isometric exercise, or a combination of the two produce an analgaesic effect?.' Br J Sports Med 2017;51:208-209, doi: http://dx.doi.org/10.1136/bjsports-2016-096107.Rotator cuff tendinopathies are the most commonly diagnosed musculoskeletal shoulder conditions and are associated with pain, weakness and loss of function.1 Tendon swelling may be associated with tendinopathy and may result from acute overload.2–3 An increase in tendon cells (tenocytes) and upregulation of large molecular weight proteoglycans, such as aggrecan, may increase tendon water content.2 There is uncertainty as to whether the swelling is related to the pain or is instead an observed but unrelated phenomenon. Weakness detected clinically may be due to pain inhibition.4–5 Early treatment of acute rotator cuff tendinopathy involves patient education and relative rest, and may include non-steroidal anti-inflammatory drugs (NSAIDs) to reduce pain, swelling and inflammation. Subacromial corticosteroid injections are also used to achieve the same purpose. These techniques show low to moderate evidence of reducing short-term pain but they do not improve function.6 The medications have side effects such as gastrointestinal tract complaints,7 and corticosteroids may damage tendon tissue.8 Identifying alternative ways to control pain and inflammation may be warranted. Two clinical procedures to manage RC tendinopathy include ice wraps and isometric exercise, however, there are no empirical data supporting their use. This pilot study, conducted at the Illawarra Sports Medicine Clinic, NSW, Australia, was designed to test (1) the short term analgaesic effect of these interventions and (2) the feasibility of a larger clinical trial for adults diagnosed with acute rotator cuff tendinopathy (<12 weeks).Peer reviewe

The Efficacy of Partial Squats on Measures of Strength and Explosiveness: An Exploratory Study

Abstract available in the 8th Annual Coaches and Sport Science College

Fatigue, Induced via Repetitive Upper-Limb Motor Tasks, Influences Trunk and Shoulder Kinematics During an Upper Limb Reaching Task in a Virtual Reality Environment

Background Efficient shoulder movement depends on the ability of central nervous system to integrate sensory information and to create an appropriate motor command. Various daily encountered factors can potentially compromise the execution of the command, such as fatigue. This study explored how fatigue influences shoulder movements during upper limb reaching. Methods Forty healthy participants were randomly assigned to one of two groups: Control or Fatigue Group. All participants completed an upper limb reaching task at baseline and post-experimental, during which they reached four targets located at 90° of shoulder abduction, 90° external rotation at 90° abduction, 120° scaption, and 120° flexion in a virtual reality environment. Following the baseline phase, the Fatigue Group completed a shoulder fatigue protocol, while Controls took a 10-minute break. Thereafter, the reaching task was repeated. Upper limb kinematic (joint angles and excursions) and spatiotemporal (speed and accuracy) data were collected during the reaching task. Electromyographic activity of the anterior and middle deltoids were also collected to characterize fatigue. Two-way repeated-measures ANOVA were performed to determine the effects of Time, Group and of the interaction between these factors. Results The Fatigue group showed decreased mean median power frequency and increased electromyographic amplitudes of the anterior deltoid (p \u3c 0.05) following the fatigue protocol. Less glenohumeral elevation, increased trunk flexion and rotation and sternoclavicular elevation were also observed in the Fatigue group (Group x Time interaction, p \u3c 0.05). The Control group improved their movement speed and accuracy in post-experimental phase, while the Fatigue group showed a decrease of movement speed and no accuracy improvement (Group x Time interaction, p \u3c 0.05). Conclusion In a fatigued state, changes in movement strategy were observed during the reaching task, including increased trunk and sternoclavicular movements and less glenohumeral movement. Performance was altered as shown by the lack of accuracy improvement over time and a decrease in movement speed in the Fatigue group

Controller of a new pulsed source for linac 4 (MEGADISCAP)

This document presents the implementation of a control system for a new multiple-stage pulsed current source converter. A new topology that has been proposed to overcome some limitations inherent to capacitor discharge converter is presented in detail and explained. Its implementation is described and the design considerations adopted are accounted for. Besides, a control strategy is proposed, which has been implemented using an existing control board with some modifications on the acquisition system. A prototype whose current and voltage are scaled down with respect to those required for the converters that will be used for CERN Booster injection with LINAC 4 has been built. This reduced scale system has been simulated taking into account the control system implementation. Finally, the topology operating principle has been validated, the results obtained with the scaled down prototype have been compared with simulations and the need for more hardware resources for the control system implementation has been demonstrated

The Impact of Experimental Pain on Shoulder Movement During an Arm Elevated Reaching Task in a Virtual Reality Environment

Background: People with chronic shoulder pain have been shown to present with motor adaptations during arm movements. These adaptations may create abnormal physical stress on shoulder tendons and muscles. However, how and why these adaptations develop from the acute stage of pain is still not well-understood. Objective: To investigate motor adaptations following acute experimental shoulder pain during upper limb reaching. Methods: Forty participants were assigned to the Control or Pain group. They completed a task consisting of reaching targets in a virtual reality environment at three time points: (1) baseline (both groups pain-free), (2) experimental phase (Pain group experiencing acute shoulder pain induced by injecting hypertonic saline into subacromial space), and (3) Post experimental phase (both groups pain-free). Electromyographic (EMG) activity, kinematics, and performance data were collected. Results: The Pain group showed altered movement planning and execution as shown by a significant increased delay to reach muscles EMG peak and a loss of accuracy, compared to controls that have decreased their mean delay to reach muscles peak and improved their movement speed through the phases. The Pain group also showed protective kinematic adaptations using less shoulder elevation and elbow flexion, which persisted when they no longer felt the experimental pain. Conclusion: Acute experimental pain altered movement planning and execution, which affected task performance. Kinematic data also suggest that such adaptations may persist over time, which could explain those observed in chronic pain populations

An exploratory study into the effects of a 20 minute crushed ice application on knee joint position sense during a small knee bend.

Objectives The effect of cryotherapy on joint positioning presents conflicting debates as to whether individuals are at an increased risk of injury when returning to play or activity immediately following cryotherapy application at the knee. The aim of this study was to investigate whether a 20 minute application of crushed ice at the knee immediately affects knee joint position sense during a small knee bend. Design Pre and post-intervention. Setting University movement analysis laboratory. Participants Eleven healthy male participants. Main Outcome Measures Kinematics of the knee were measured during a weight bearing functional task pre and post cryotherapy intervention using three-dimensional motion analysis (Qualisys Medical AB Gothenburg, Sweden). Tissue cooling was measured via a digital thermometer at the knee. Results Results demonstrated significant reductions in the ability to accurately replicate knee joint positioning in both sagittal (P=.035) and coronal (P=.011) planes during the descent phase of a small knee bend following cryotherapy. Conclusion In conclusion a twenty minute application of crushed ice to the knee has an adverse effect on knee joint repositioning. Team doctors, clinicians, therapists and athletes should consider these findings when deciding to return an athlete to functional weight bearing tasks immediately following ice application at the knee, due to the potential increase risk of injury

How Does Cryotherapy Effect Ankle Proprioception in Healthy Individuals?

Objectives: To investigate how a 15 minute Cryotherapy intervention effects proprioception by measuring Joint positional Sense (JPS) and static single legged balance. Design: Repeated measures design. Setting: Laboratory. Participants: Eighteen healthy university sports team students (11 males, 7 females) aged between 20-21 years. Main Outcome Measures: Participants were treated with 15 minutes Aircast Cryo-cuff. The subject’s skin temperature was measured before and immediately after 15 minutes Cryotherapy treatment. Ankle active joint positional sense (A-JPS) and passive joint positional sense (P-JPS) was measured at pre-test, immediately post-test and 5 minutes post-test. Static balance was measured by Centre of Pressure (CoP) mean path length, medial-lateral (ML) CoP mean Deviation and anterior-posterior (AP) CoP mean Deviation and mean time-to-boundary (TtB) Minima for AP and ML directions. Results: No significant differences found for the variables of JPS and static single balance testing after 15 minutes Cryotherapy treatment. However, mean differences for CoP mean path length and ML mean deviation were shown to improve following Cryotherapy treatment, results not previously found in the literature. Conclusion: Results suggest that 15 minute Cryo-cuff treatment doesn’t significantly affect proprioception. Although the effect of Cryotherapy on proprioception depends on cooling modality used, time frame applied and joint applied to

Injuries, Ill-Health and Fatalities in White Water Rafting and White Water Paddling

White water (WW) activities such as paddling (canoeing and kayaking) and rafting are popular sports for recreational and professional participants. An increase in participation has been seen worldwide. However, these activities come with a risk of injury and even death if not conducted safely. A review was conducted to identify the types of injuries and ill-health that occur as a result of these activities. Injury and fatality rates were assessed to establish the risk attributed to these activities. Web of Science, PubMed, Ergonomics Abstracts and PsycINFO databases were searched and a total of 16 published articles were identified and reviewed. The shoulders and back were the most vulnerable sites for injury in WW paddling. Injuries to the face and lower limbs were most common in WW rafters. However, injury rates are low and estimates are discussed. Due to different methods used across the studies, the reported injury rates are not comparable. This review identified three illnesses incurred through WW activities. There may be more but these are not currently reported in the literature. A relative paucity of studies regarding injuries and fatalities in WW activities was identified. Directions for future research are suggested and discussed