Biomedical subjects

Eric M Lamberg

Publications and source records attributed to Eric M Lamberg.

4 recordsLinked to original sources

PubMed2006

Cardiovascular response to treadmill testing in Parkinson disease.

PURPOSE: Exercise has been recommended as a way to maintain quality of life in individuals with Parkinson disease (PD). Experiments examining the cardiovascular response to exercise, however, have yielded controversial results. This study was designed to determine if there is any difference in vital signs and Rate of Perceived Exertion (RPE) between a group of individuals (50-80 years old) with PD and a comparison group of healthy individuals during exercise on a treadmill. METHODS: Twenty seven volunteers (16 with PD and 11 healthy) participated in this study. Subjects with PD were divided into 2 groups; one that reached target heart rate and one that failed to reach it. In this study, heart rate (HR), systolic blood pressure (BP), and the RPE were measured during a Modified Bruce Protocol. We hypothesized that treadmill testing would result in differences between individuals with PD and healthy subjects when HR and systolic BP were compared at submaximal exercise (defined as Stage 2 of the Modified Bruce Protocol) and at peak exercise (defined as 85% of age predicted target heart rate). RESULTS: During submaximal exercise, no significant differences were found between the PD group and the control group for HR, BP, or RPE. At peak exercise, one half of the subjects with PD exhibited blunted cardiovascular responses, despite reaching a comparable intensity of exercise during a Modified Bruce Protocol. CONCLUSIONS: Although cardiovascular responses to exercise on a treadmill appear similar between individuals with PD and controls at lower levels of exercise, half the subjects with PD in the present study displayed abnormal cardiovascular responses at higher exercise intensities. Administering an exercise stress test will illustrate the expected cardiovascular responses for each individual, therefore guiding exercise prescription.

Aged↗

PubMed2005

Natural breath control during lifting tasks: effect of load.

Anecdotal evidence suggests that people hold their breath during lifting tasks in order to increase intra-abdominal pressure (IAP) and thereby increase lumbar stability. Studies have shown that voluntary control of the breath influences IAP and that increases in IAP are related to increases in lumbar stability. However, a description of naturally occurring breath control during whole-body lifting tasks in normal healthy subjects is currently not available. Therefore, the specific aims of this study were to: (1) determine the naturally occurring breath patterns during lifting tasks in healthy subjects; (2) determine the effects of different levels of load during lifting tasks on natural breath control patterns in healthy subjects. The present study enrolled 20 healthy subjects to describe inspired volume and categories of airflow direction (inspiration, expiration, or breath hold) during two self-paced lifts of crates loaded at 5, 15, and 25% of body weight. When the breath pattern was examined across all loads there was a significant increase in the magnitude of inspired volume and the frequency of occurrence of inspiration immediately prior to lift-off. When examining the effect of load on breath patterns, there was a significant increase of inspired volume and occurrence of breath holding when lifting the heavy load compared to the medium and light loads. These results suggest that: (1) distinct patterns of natural breath control occur during lifting tasks; and (2) breath control is responsive to the timing and magnitude of load lifted.

Breathing Exercises↗

PubMed2005

Visual properties of objects affect manipulative forces and respiration differently.

Previously, we demonstrated that the respiratory and motor systems responded differently following consecutive lifts of an object whose weight could be altered (lighter or heavier) without changing the object's visual properties. When the weight of the object was altered in a manner unpredictable to the subject, the motor system response reflected the previous weight of the object (light or heavy) while the respiratory system reflected responses seen when lifting the heavier object regardless of whether a lighter or heavier object was lifted previously. It is possible that the default pattern of the respiratory system was due to a lack of visual size cues, which are known to have robust affects on grasp control. To test this hypothesis, 14 seated subjects performed self-initiated alternating lifts with objects whose size and weight covaried such that the weight of the upcoming lift was known despite the weight of the object previously lifted. Following both consecutive and alternating trials, the load force was scaled to the weight of the object (e.g., the heavier the object the larger the force) while the volume was scaled only following the consecutive trials. This suggests that the load forces were developed entirely based on visual information while lung volume was not. In addition, we suggest that following the consecutive trials, the volume increased as the object's weight increased in an effort to assist with trunk stabilization by indirectly increasing intra-abdominal pressure.

Adult↗

PubMed2003

Internal representations underlying respiration during object manipulation.

We examined the presence of anticipatory control and the resulting interactions of the respiratory and motor systems during discrete object manipulation. In response to an auditory signal, subjects reached forward, grasped, and lifted an instrumented object weighing 150 or 1000 g while the breathing pattern, fingertip forces, and movements were measured. Following every block of five lifts, the object was removed from sight and replaced with the same or an alternate mass. Thus, the object's weight was predictable during the last lift of each block and unpredictable during the first lift after the transition. When the object's weight was predictable, the force application was faster and inspiratory duration and the tidal volume were reduced for the breath associated with the lift for 1000-g compared to 150-g lifts. Following the transition, when the object's weight was unpredictable, the force application reflected the weight of the object during the previous lift while the respiratory output, regardless of the preceding weight, resembled that used for 1000-g lifts. Additionally, inspiratory duration was significantly correlated with the reach duration in three of the four unpredictable lifting conditions. We conclude that these system-specific anticipatory alterations may arise from a common internal representation that was formed through past manipulatory weight experience.

Adult↗