History / Progression
This research design incorporated an evaluative case-study approach where detailed qualitative and quantitative data were collected over 14 weeks on one super obese Caucasian female (44 years of age; 1.65 m; 188.6 kg; BMI: 69.2) as she participated in a 3 session per week physical therapy exercise the AlterG Anti-Gravity Treadmill. Physician, University Review Board, and participant approval were obtained, a medical history completed, resting blood pressure and heart rate determined, and complete blood labs (cell count, chemistry panel, glucose, and lipid profiles) were secured prior to commencing exercise. The participant was also interviewed to develop a patient history relating to lifetime dietary patterns and physical activity levels.
Repeated assessments during the study included the following:
a) Subjective ratings of physical and mental health
b) Anthropometric measures
c) Heart rate
d) Rating of perceived exertion (RPE) and rating of pain
e) Step counts
f) Diet history and daily food journalsPre- and post-intervention ratings of physical and mental health were determined using the SF-36v2 (Quality Metric Health Outcomes Solutions, Lincoln, RI). Anthropometric measures consisted of body circumferences of the chest, upper arm, waist, hips, thighs, calves, knees, and ankles, as well as body weight.Weight and lower extremity circumferences were recorded once per week, while measurements of the chest, upper arm, waist, and hips were reported approximately every four weeks. The participant also logged daily food intake. This information was entered into Diet Analysis Plus 9.0 CD-ROM and was analyzed bi-weekly.
During the walking exercise sessions, heart rate (HR) was monitored using a Polar 600 Heart Rate Monitor. Rating of Perceived Exertion (RPE) was determined using the Borg scale of 6–20, as was pain on a scale of 0 – 10, with 0 representing no pain and 10 the most intense pain imaginable. The ACSM metabolic equations were used to estimate caloric expenditure for each session. A Yamax SW200 pedometer was initially placed on the back waistband of the participant to accommodate a more vertical position; however, contact from the seal of the AlterG prevented the pedometer from accurately recording step counts. As a result, overall step counts were determined by counting the exact steps taken per minute at each walking speed employed during the study. The participant demonstrated no adverse hypertensive events during physical activity.
AlterG Walking Program
Week 1 – Day 1
The initial exercise session (day 1) was conducted to determine a comfortable walking speed at a pain-free level, subjectively determined by the participant. There were no appropriate-sized AlterG shorts available for the participant to wear. The air cushion opening alone was large enough to form a tight seal around her hips (up to 40% weight bearing, at which point leaks developed).After she was fitted into the treadmill, the speed was set at a comfortable pace of 2.4 km/hr. Heart rate and BP were recorded before the AlterG LBPP device was activated. The AlterG was then activated and used to support 10% of the participant’s body weight while HR and BP were again recorded. This procedure was repeated in 10% increments of body weight until the participant reported pain free walking at 60% of body weight.
Week 1 – Day 2
Prior to beginning the walking sessions (which occurred on day 2), knee, calf, and ankle joint circumference measurements were obtained to determine baseline levels for joint edema/swelling. The participant also provided subjective accounts of pain, function of daily activities, or other accounts from the past two days.
The participant’s exercise began with a 5 min warm up at 2.4 km/hr and LBPP at 60% of body weight. Speed gradually increased to 3 km/hr at 60% of body weight for another 10 min of walking, after which a 5 min cool-down ended the exercise session. Speed was gradually decreased to 2.4 – 2 km/hr by the conclusion of the cool-down period.
Heart rate, RPE, pain, and the talk test (determines ease of communication/walking intensity) were initially measured at 1 min intervals and extended to 5 min when the subject demonstrated an ability to exercise without complications. Intensity levels were kept in the moderate range 40 – 59% of heart rate reserve (HRr), based on age predicted maximum HR. Walking at 60% body weight allowed walking with pain to be < 1 on a scale of 1 – 10.
Exercise sessions then consisted of the participant walking at a comfortable speed with enough LBPP support to reduce knee pain to <1. Exercise HR, pain level and RPE were used to determine when to increase exercise intensity. Time and speed were increased and LBPP reduced as tolerated. Exercise sessions were terminated if HR reached 65% of HRr, an RPE of 15 or higher was declared, or the participant was unable to comfortably converse in simple sentences. This exercise prescription was followed 3 days per week.
Download Case Study to see progression table