THE EFFECT OF BAG MASS ON THE SHOULDER AND HIP POSTURAL ANGLES OF 4A2012 STUDENTS

TABLE OF CONTENTS Abstract Problems and Hypotheses Background of the Study Variables Methodology Data Presentation Analysis of Data Conclusion Closure Sources 

ABSTRACT Problem: muscle pain due to heavy bags Project: postural analysis- shoulder-shoulder and shoulder-hip angles Results: angles increase as bag mass increases Note: greater change in angles in lighter subjects Effect: inform students of ideal load weight

PROBLEMS and HYPOTHESES 1. How does bag mass affect the shoulder-shoulder angle? If the mass increases, so will the angle.   2. How does bag mass affect the shoulder-hip angle? 3. How does the subject's mass affect the angles?  If the mass increases, angles will decrease.

BACKGROUND Shoulder-supported bags are commonly used by students Carrying beyond safe load-bearing (5-10% of body mass) prevalent in adolescent students  Bags may induce postural deficiencies Study aims to provide information for musculoskeletal well-being of bag-users

VARIABLES Independent: Total bag mass, Weight of subject   Dependent: Shoulder-shoulder angle, Shoulder-hip angle Constant: Type of bag, Type of weight, Type of postural analysis grid, Position of feet

Neutral position with marked joints METHODOLOGY The subject was weighed. The postural analysis grid (PAG) was posted. Control setup: subject stood in a neutral position with no bag. Shoulder-shoulder and hip-shoulder angles were measured using arctangent functions. Neutral position with marked joints

Experimental setup (shoulder-hip) METHODOLOGY Experimental setup: subject stood in a neutral position with a bag weighing 3 kg, 6 kg and 9 kg. The shoulder-shoulder and hip-shoulder angles were measured using arctangent functions.  Twenty test subjects were taken. Experimental setup (shoulder-hip)

DATA PRESENTATION   The graph shows that as the weight of the bag increases, so does the shoulder-shoulder angle.

DATA PRESENTATION The graph shows that as the weight of the bag increases, so does the shoulder-hip angle.

DATA PRESENTATION The graph shows that as the weight of the subject increases, the shoulder-shoulder angle decreases.

DATA PRESENTATION The graph shows that as the weight of the subject increases, the shoulder-hip angle decreases.

ANALYSIS As mass increases, so does the weight. The shoulder muscle and bone shift downward and forward. This compensates for a change in the center of gravity. Equilibrium is achieved. Law of Acceleration (F=ma)

CONCLUSION Weight matters in postural differences Further research: - Bag: Heavier bag, greater change - Body mass: Heavier subject, less change Further research: - More precise measuring instruments for better data quality - Observe changes in muscle activity as well

CLOSURE Heavy backpacks can ruin a student’s body. What are you going to do about it?