Abdominal Muscle strength & its correlation with the BMI (Body Mass Index) – A survey in medical students

Purpose: Obesity is currently regarded as public health problem that affects both young people and adults. Besides arterial hypertension, diabetes, cardiovascular disorders, degenerative joint disease, sleep apnoea and increased vulnerability to injury, these patients usually present with bad posture that may contribute to both low self-esteem and additional long term adverse effects on bones and joints. Relevance: The obese individual often displays a protruding abdomen which results in anterior displacement of center of gravity, associated with an increase in lumbar lordosis and anteversion of pelvis. Continual exaggeration of curves leads to postural impairment and muscle strength and flexibility imbalances as well as other soft tissue restriction or hypermobility. Muscles that are habitually kept in a stretched position tend to test weaker because of a shift in the length tension curve; i.e. known as stretch weakness. So the aim of the study is to know thecorrelation between abdominal muscle strength and BMI (Body Mass Index) in females and males. Participants/ Subjects: 60 participants (35 males & 25 females) with the age group of 18-25 years were taken in study from S.B. B. College of physiotherapy, Ahmadabad, after checking for inclusion & exclusion criteria. Methods: BMI was measured using height and weight.Waist circumference was measured with measure tape. Upper and lower abdominals were tested using manual muscle testing and transversus abdominals was tested using pressure biofeedback unit. Analysis: The Pearson’s correlation coefficient was found using graphpad software for analysis. Results: Mean BMI for females and males were 22.198 and 23.0052 kg/m 2 respectively. Mean BMI was higher in males than in females. In females, correlation coefficient between BMI and UA (Upper Abdominals) was negative and extremely significant (r=-0.60000, p=0.0001) for BMI and LA (Lower Abdominals) was also negative and highly significant (r=-0.4899; p=0.0028) and for BMI and TA (Transversus Abdominis) was not significant (r=0.01138, p=0.9483). In males, correlation coefficient for BMI and UA was negative but not quite significant (r=-0.3407, p=0.0956), for BMI and LA was also negative but not quite significant (r=-0.3601, p=0.0770) and for BMI and TA was not significant (r=0.1326, p=0.5273). Results showed that with increasing BMI and waist circumference there is decrease in upper and lower abdominals strength in females but not in males. No significant results were found for transversus abdominis. Correlation coefficient of BMI and WC for female is positive and extremely significant (r=0.9053, p<0.0001) and for male is also positive and extremely significant (r=0.9231, P<0.0001). So, with increasing BMI there is increase in WC in both males and females. Conclusions: There is negative correlation between BMI and abdominal muscle strength in females not in males. Future research can be done in sedentary individuals by grouping them in obese & nonobese categories. Implications: While prescribing the exercise programme for obesity, abdominal muscle strengthening exercises should be included in the programme. Keywords: Abdominal muscles, BMI, Waist circumference. Funding source Acknowledgement: The work was funded by S.B. B. College of physiotherapy, Ahmadabad.