The effect of wearing the complete Lenox Hill Derotation Brace on energy expenditure during horizontal treadmill running at 161 meters per minute

Abstract

Ten volunteer subjects (x age = 26.6 ± 4.9 years, x height = 177.9 ± 5.6 cm, and x weight = 76.9 ± 11.2 kg) who had been wearing the Lenox Hill Derotation Brace (LHB) for a mean time of 23.9 ± 28.0 months were familiarized with horizontal treadmill running at 161 m/min with and without the LHB. They were then tested randomly for four runs, two with the LHB and two without the LHB. Metabolic measurements using a device that counted footstrikes on the treadmill were taken during the 3rd and 6th minutes of each run. Regardless of sampling time, wearing the LHB pro duced significantly higher values for VO₂ (4.58%, P < 0.025) and heart rate (5.10%, P < 0.004) compared to the no brace condition. Regardless of whether or not the subjects were wearing the LHB, 6 minute values were significantly higher than 3 minute values for VO₂ (5.89%, P < 0.0004), V_E (10.08%, P < 0.004), heart rate (5.35%, P < 0.0000), and R (2.17%, P < 0.038). The mean 6 minute values of VO₂ with (37.42 ± 3.55 ml/kg/min) and without (35.54 ± 2.17 ml/kg/min) the brace fall within the range of expected values of 28.1 to 39.3 ml/kg/min derived from regression equations from the literature which predict VO₂ response to hori zontal treadmill running. Mean stride lengths while wearing the LHB (97.85 cm) were not significantly different from mean stride lengths without the LHB (98.56 cm). It is concluded that wearing the LHB pro duces a 4.58% increase in energy expenditure during horizontal treadmill running at 161 m/min which cannot be attributed to changes in stride length or to time of sampling during the run.