• Physical Therapy Korea
• /
• v.18 no.1
• /
• pp.74-82
• /
• 2011

The purpose of this study was to compare the anaerobic threshold (AT) between subjects with and without non-specific chronic low back pain (NCLBP). The patient group included 15 women with NCLBP. The normal group included 15 women without NCLBP who were age-, height-, weight-, and activity level-matched. The subjects performed a Balke treadmill protocol which was symptom-limited progressive loading test. Their heart rate (HR), ventilatory gas and metabolic equivalents (METs) were measured using the automatic breath gas analyzing system. After the test, each subjects' ratings of perceived exertion (RPE) were evaluated. The visual analog scale (VAS) was assessed pre- and post-test. The independent t-test and Wilcoxon's signed-rank test were used for analysis of the data. Time, HR, the volume of oxygen consumption ($VO_2$), relative $VO_2$, and METs at the AT level of the patient group were significantly lower than those of the healthy group (p<.05). However, there were no significant differences in RPE, VAS, and breathing frequency at the AT level (p>.05). The findings of this study indicate that patients with NCLBP had a lower aerobic fitness than healthy subjects. Thus, implementation of rehabilitation program to increase aerobic fitness may be considered in patietns with NCLBP, and further studies are required to determine the etiological factors of decreased aerobic fitness.

• Proceedings of the KOSOMBE Conference
• /
• v.1990 no.05
• /
• pp.7-8
• /
• 1990

In this study, a new ensemble average technique was developed to measure cardiac output during treadmill exercise. Each dZ/dt peak (C point) was used as a starting point for ensemble averaging, instead of conventionally used R wave of ECG in order to prevent the peak dZ/dt waveform from blurring. In ease of using R wave as a reference, time interval from R wave to the peak of dZ/dt varies for each heart beat. Stroke volume, heart rate, and cardiac output of five male were successfully measured with Balke protocol using the new ensemble average technique.

• Physical Therapy Korea
• /
• v.12 no.3
• /
• pp.74-83
• /
• 2005

The purpose of this study was to produce the regression equation from non-exercise $VO_{2max}$ of healthy young adults and to develop a maximal oxygen consumption ($VO_{2max}$) regression model. This model was based on heart rate non-exercise predictor variables (rest heart rate, maximal heart rate/rest heart rate), as an extra addition to the general regression which can reflect an individual's inherent or acquired cardiorespiratory fitness. The subjects were 101 healthy young adults aged 19 to 35 years. Exercise testing was measured by using a Balke protocol for treadmill and indirect calorimetry. The prediction equation was analyzed by using stepwise multiple regression procedures. The mean of $VO_{2max}$ was $39.02{\pm}6.72\;m{\ell}/kg/min$ (mean${\pm}$SD). The greatest variable correlated to $VO_{2max}$ was %fat. The predictor variable used in the non-exercise $VO_{2max}$ included %fat, gender, habitual physical activity and $HR_{max}/HR_{rest}$. The non-exercise $VO_{2max}$ estimation was as follows: $VO_{2max}$($m{\ell}/kg/min$)=55.58-.41(%fat)+.59(physical activity rating)-2.69($HR_{max}/HR_{rest}$)-5.36 (male=0, female=1); (R=.85, SEE=3.64, R2=.72: including heart rate variable); $VO_{2max}$($m{\ell}/kg/min$)=48.47-.41(%fat)+.45(physical activity rating)-5.12 (male=0, female=1); (R=.84, SEE=3.74, R2=.70: with the exception of heart rate variable). As an added heart rate variable, there was only a 2% coefficient of determination improved. Therefore, these results demonstrated that heart rate variable correlation with a non-exercise regression model was very low. In conclusion, for healthy young korean adults, those variables that can affect non-exercise $VO_{2max}$ estimation turned out to be only % fat, gender, and physical activity. We suggest that further research of predictor variables for non-exercise $VO_{2max}$ is necessary for different patient groups who cannot perform maximal exercise or submaximal exercise.