Unilateral Leg Training, Part 1: Historical Perspectives
The history of the human body is long and varied. From prehistoric times to modern times, there have been many changes in our bodies.
The evolution of our bodies is one of the most fascinating aspects of biology. Changes in muscles are not only due to genetic factors but also due to environmental conditions such as exercise or diet. There are various types of exercises which affect muscle growth and development; however, they all share common features. These include the use of weights, resistance bands, machines, free weight movements and other types of exercises.
In this article we will focus on the historical perspective of unilateral leg training. We will discuss how these exercises were used in ancient times and what their effects were on muscle growth and development.
Ancient History – Ancient Times to Modern Times
The first recorded example of bilateral (one-sided) leg exercise was found in China during the Shang Dynasty (c. 2400 BC).
A man named Li Shizhen discovered that when two men performed the same movement with opposite legs, the result was different. He called this phenomenon “Li Shizhen’s method”. The technique was later described in several books including the book titled ‘The Book of Motion’ by Sun Tzu (c. AD 200).
During the Qin Dynasty (221BC-207BC), there were numerous exercises to strengthen both sides of the body. The most important was ‘horse riding’, which involves a person sitting sideways on a horse-riding saddle and bending one leg, while the other hangs down.
During the Han Dynasty (206BC-220AD), exercise became very popular in China. The most common form was horseback riding.
A long, raised platform was built, allowing the rider to sit sideways on the horse and hang one leg while sitting on the other. The strain caused by the leg muscles supporting the body was believed to be good for health. In addition, people began using large stones as weights that were similar in size to babies.
During the Song Dynasty (960-1279), it was common for one leg to be placed on a low table and then sit on a swing while holding the table to maintain balance. This method of exercise was called “riding a swing with weights”.
It was believed to be good for posture and spinal health.
From the beginning of the Qing Dynasty (1644-1911), traditional leg exercises were very popular in England. In particular, leg extension became more common among the upper class.
There are even records showing that leg exercises were used by women to improve their figures.
In modern times, activities such as running and dancing have become popular among all levels of society. Depending on the activity, some are used to enhance speed while others are used to enhance muscular endurance.
Bilateral (One Sided) Exercises
In the past, unilateral leg exercises were considered to be more effective than bilateral leg exercises due to the effects of each muscle. Bilateral leg exercises involve both legs performing an equal amount of work, with one side not working any less or any more than the other side.
Unilateral leg exercises, on the other hand, involve performing an exercise with one leg and not the other. This means that the ‘working’ leg is responsible for all of the work that is required to perform the movement.
The ‘non-working’ leg then becomes an observer which tries to assist the working leg by providing some of the power needed to complete the movement. The effect is that one side of the body is more effective than the other.
Sources & references used in this article:
Pre-participation screening: the use of fundamental movements as an assessment of function-part 1. by G Cook, L Burton, B Hoogenboom – North American journal of sports …, 2006 – europepmc.org
Lumbar stabilization: core concepts and current literature, Part 1 by KP Barr, M Griggs, T Cadby – American journal of physical …, 2005 – journals.lww.com
Prevention of non-contact anterior cruciate ligament injuries in soccer players. Part 1: Mechanisms of injury and underlying risk factors by E Alentorn-Geli, GD Myer, HJ Silvers, G Samitier… – Knee surgery, sports …, 2009 – Springer