ONE ARM DUMBBELL ROW
[An innovative analysis] – A little aspect of Physio-analysis
Imagine an individual who weighs about 70 kg. The features of his upper limb [55 cm long] are as follows;
Arm length [Shoulder to elbow distance] = 25 cm
Forearm length [Elbow to wrist distance] = 30 cm
This individual now attempts to perform an exercise called ‘One arm dumbbell row’ with 8 kg dumbbell. When he completely performs one row from neutral position [figure:1], his arm remains elevated to about 30 degrees from horizontal [figure:2].
[ Figure:1] [ Figure:2]
Calculation [This type of formulae, I am planning to innovate and introduce in my textbook on Biomechanics, having Pythagorean theorem as basis]
The Total Distance Traveled by Dumbbell [TDTD] from neutral position to its position as in figure:2 can be calculated as follows;
TDTD = √[Upper limb length – (Forearm length – {Arm length x sine 30 degrees})]2 - [Arm length x cosine 30 degrees]2
= √ [ 55 cm – (30 cm – {25 cm x 0.5})]2 - [25 cm x 0.866]2
= √ 1406 cm2 – 467 cm2
= √939 cm2
Therefore, TDTD = 31 cm [approx] or 0.31 meters.
This TDTD can be simply considered as ‘D’ of the formula of WORK DONE. [Note: TDTD measurement can also be replaced with a simple inch tape measure of distance traveled by Dumbbell]
WORK DONE [W] = Force [F] x Distance traveled [D]
When the work done [W] is computed in joules, it is possible to correlate joules with calories. Hence , we can guesstimate the calories burnt by an individual during the training session by summating the joule expenditure of all types of his workouts.
