Tag: Andy Karduna

Movement Direction and Shoulder Orientation Alter Elbow Joint Position Sense

Presenter: Tayson Heward

Mentor: Andy Karduna

AM Poster Presentation

Poster 15

Proprioception is the body’s ability to sense its position and movement without visual input. Proprioception of the elbow and shoul- der has been shown to be most accurate when elevation or flexion angles are at 90 degrees. Investigations in shoulder orientation and movement direction may lead to a better understanding of what is playing the largest role in this heightened sense at 90 degrees. This study looks at the effects of shoulder orientation and movement direction on elbow joint position sense (JPS). With an aim to look at what is increasing proprioceptive acuity as you increase flexion angle to 90 degrees, we predicted that an increase in shoulder orientation would increase elbow JPS, but movement direction would have little effect on JPS. Subjects had the same 3 target angles; 50, 70, and 90 degrees, that the subjects would memorize their elbow position then actively mimic the position. There were two different 2-way interactions found; one between angle and orientation, and another between movement direction and shoulder orientation. This indicates that elevating your shoulder to 90 degrees increases elbow JPS. Also, extension at the elbow may be lead to better elbow JPS than flexion, yet shoulder orientation possibly negates this effect. Analysis is ongoing and further conclusions are in development for this study.

The Reliability of Ultrasound Imaging as a Tool with Which to Evaluate Muscular Activation in Patients with Impingement Syndrome

Presenter: Lauren Maloney

Faculty Mentor: Andy Karduna

Presentation Type: Poster 75

Primary Research Area: Science

Major: Human Physiology

Differences in muscular activation in the context of dysfunctional muscles has been a field of particular interest in diagnosing disorders and determining possible causes of musculoskeletal pathologies. Electromyography (EMG) is a technique that measures the electrical activity of muscles via electrodes, and is the most commonly used technique for assessing muscular activation. However, EMG is invasive and difficult to carry out easily in clinical settings. In this study, we evaluated ultrasound images of symptomatic and asymptomatic limbs of 30 patients with unilateral shoulder pain in comparison to a “gold standard” technique and found that ultrasound is a reliable and valid tool for determining muscular width of the supraspinatus. Using this data, we compared differences in muscular activation between symptomatic and asymptomatic limbs of patients.

The role of limb dominance in visuoproprioceptive tasks

Presenter(s): Kieley Trempy

Faculty Mentor(s): Kate Spitzley & Andy Karduna

Poster 30

 Session: Sciences

Movement is the product of sensory input, mainly from vision and proprioception, and motor output. Vision is the sense of the surrounding space and proprioception is the sense of the body’s position in space. Joint position sense (JPS) is commonly used as a measure of proprioception. JPS of the dominant and nondominant shoulder was measured in healthy subjects to quantify error in a JPS task with and without visual information. Previous studies have examined sensory differences in limb dominance with conflicting results. Some have shown that no differences exist, while others show that movements with the dominant arm rely more on visual information and movements with the nondominant arm rely more on proprioceptive information. The latter theory is illustrated in activities of daily living, such as with preparing food, where the dominant arm uses a knife by viewing the movement while the nondominant arm guides the food by feeling the movement. It was hypothesized that in a JPS task, the dominant arm would have less error with visual information whereas the nondominant arm would have less error without visual information. Subjects wore a virtual reality headset with a tracker on their arm while performing a JPS task. Using the headset, subjects were presented with either a visual representation of their arm location or no visual information about arm location. No difference was found between sides. However, difference was seen between the vision and no vision conditions regardless of limb dominance. Higher error with no vision indicates that proprioception alone is not as effective in driving accurate movements as the combination of vision and proprioception. Future studies analyzing the contributions of vision and proprioception to movement may rule out variation associated with limb dominance.