What is Human Movement?

Humans can move from one place to another through coordinated movements and postures. The movement produced by the human body due to the contraction of muscles and bending of bone joints is called human movement. Human movements are controlled by the nervous system. Hence, the human movement incorporates the use of muscles, ligaments, joints, and bones.  Kinesiology is the field that deals with the study of human movements.

What is meant by Human Movement studies?

Human movement studies are associated with research of human movement. The research on variations in human movement in different contexts also takes place in human movement science. Human movement studies are used to understand the physical and psychological effects of physical activities on the human body.

The regulation of movement through the nervous system is studied to understand how the brain influences human movement. The nervous system is also responsible for coordinating those human movements.

Musculoskeletal system

The musculoskeletal system comprises the muscular and skeletal systems.

Muscular system

The muscles tissue is a contractile tissue that makes up the muscular system. The muscle present in the heart which is responsible for its contraction is the cardiac muscle. The muscles present in the tube-like structures, like blood vessels, are called smooth muscles. The muscles that are responsible for limb movement are skeletal muscles. 

The muscular system also contains structures known as tendons. These structures are made up of connective tissues. The tendons are attached to the muscles and bones and act as the connecting link between them.

Skeletal system

Bones are the main components of the skeletal system. The bones contain calcium phosphate minerals and collagen protein. The bone contains two layers. The outer layer is called compact bone, while the inner layer is called spongy bone. The compact bone provides a rigid appearance to the bone while spongy bone performs metabolic functions.

The bone is supported by cartilages which are also a part of the skeletal system. It is made up of connective tissue. The cartilage can be hyaline cartilage which can be found in joints. The articulating bones contain articular cartilage that prevents friction during the gliding of bones.

The joints are responsible for combining two bones. The joint is the location where bones pivot to move. The joints can be of three types: 

• Synovial joint have a space present between two bones known as a synovial cavity. This type of joint allows maximum movement.
• Fibrous joint connects the bones through fibrous connective tissue, which allows the least movement. 
• Cartilaginous joint connect the bones through cartilage and allow a medium range of movement.

The ligaments are the component of the skeletal system that is responsible for the connection of two bones.

Muscle contraction

The contraction of muscles is responsible for the movement, which is done by the action of myosin and actin filament present in the sarcomere of muscle fibers. The myosin head forms a bridge by attaching to the actin filament with the help of ATP (adenosine triphosphate). The calcium ions are responsible for initiating this mechanism. 

The sensory neurons attach with the muscle fibers to detect the stimulus and send signals to the brain. From the brain, motor neurons carry the signal for starting or stopping muscle contraction. The junction formed by this attachment is known as the neuromuscular junction. The neurotransmitter that is released by motor neurons at this junction is acetylcholine. 

Biomechanics of human movement

The study of the mechanics involved in the biological system is known as biomechanics. The forces, their effects, and motion produced by these forces are considered mechanics. Biomechanics of human movement is the research field associated with the forces applied on the skeletal system and muscular system involved in human movement. The response generated in the musculoskeletal system due to these forces is also studied.

Elements of human biomechanics

There are four main elements of human biomechanics, which are as follows: 

• First is the statics, which describes the system present in resting condition or at the constant motion, maintains a constant equilibrium.
• The second element is dynamics that focus on the factors leading to the motion of an object.
• The third element is kinetics that describes the forces and motion leading to the movement.
• The fourth element is kinematics that describes the effect of the forces and the motion of the body without analyzing the force involved. 

The kinetics and kinematics explain the concept of dynamics.

Kinematics

There are certain variables of the kinematics that define human movement.

• There are two types of motions: linear motion, in which the speed and direction are the same for all parts of the body, and angular motion, in which the body part rotates around a rotational axis. Most of the human movements take place with the combination of these two motions.
• The magnitude of linear motion is calculated by the distance covered by the body. The magnitude of the angular motion is calculated by the angle of movement in degrees or radians. 
• The speed and velocity are determined to evaluate the rate of human movement.
• Human movement takes place in three planes: the frontal plane, sagittal plane, and transverse plane.

Types of Movements

The movements that occur in the sagittal plane are as follows:

• Flexion, in which the angle reduces between two parts of the body.
• Extension, in which the angle increases between two parts of the body. 
• When the angle increases too much, then the movement is known as hyperextension.
• When the angle reduces too much, then it is known as hyperflexion.

The movements occurring in the frontal plane include the following:

• Abduction is the movement in which the body parts move away from the midline.
• Adduction is the movement in which the body parts move towards the midline.

The movement that occurs in the transverse plane is rotational. The rotation can be two types:

• Internal rotation causing the movement of a limb toward the midline.
• External rotation causing the movement of a limb away from the midline.

The other types of movement include:

• Circumduction involves the circular movement of one end of a body part while the other end remains stationary.
• The dorsiflexion is the movement at the ankle joint where the foot moves towards the leg.
• The plantarflexion involves the movement of the foot in which it points downwards.

Lever System

The system that moves with the help of bones, joints, and muscles is known as the lever system. The lever system includes a lever that is a rigid rod-like structure, a pivot or fulcrum that provides support to the lever during movement, a load that requires lifting, and the forces that lead to the movement of the body. There are two types of forces: The effort force that causes the resultant movement and the resistant force causing the opposing movement. 

In the human body, the bones and muscles act as the lever; joints act as a fulcrum or pivot; the external objects or the part of the body that has to be lifted represent the load. The muscles provide the effort force, while the load provides the resistant force. 

There are three classes of lever systems based on the arrangement of bone, muscles, and joints. The pivot is present in the first class of lever between the effort force and the resistant force. In the second class of lever system, the resistant force is present between the pivot and the effort force. In the third class of the lever system, the effort force is present between the resistant force and the pivot. The most common lever system found in the human body is the third class of lever systems.

Importance of human movement

There are various health benefits of regular human movements (exercises, walking, and cycling).

• Human movement is important for increasing the strength of the muscles of the body, which helps in the balance and coordination of the body.
• Human movement can help the bone to become denser, which increases its durability.
• Human movement, like exercise, increases the range of motion of the joints and makes them more flexible.
• The daily human movement can also help develop those regions of the brain that are related to cognitive abilities as they begin to decline with growing age.
• The human movement improves the heart rate and decreases the risk of heart-related problems like heart attack and heart failure.
• Regular human movement improves the blood pressure in the body.

Common Mistakes

The biomechanics of human movement may be assumed to be simply a topic of physics. However, it is a combined study of physics and biology to understand how human movement takes place.

Students may assume that the force is only provided from the outside of the body to produce human movement. However, the tissues of the body also produce pressure to move the structures of the body.

Context and Applications

This topic is significant in the professional exams for undergraduate, graduate, and postgraduate courses, especially for the following:

• Bachelor of Science in Human Movement and Sport Sciences
• Masters of Science in Human Movement and Sport Sciences
• Doctorate in Human Movement and Sport Sciences

Related Concepts

• Kinesiology
• Physical education
• Skeletal system
• Muscular system

Practice Problems

Q1: Which of the following field includes the study of movements in humans?

(a) Geology

(b) Kinesiology

(c) Paleontology

(d) Sociology

Correct choice: (b)

Q2: In which of the following plane does the flexion and extension movement occur?

(a) Frontal plane

(b) Transverse plane

(c) Sagittal plane

(d) None of the above

Correct choice: (c)

Q3: In which of the following class of lever systems, the pivot present between effort and resistance force?

(a) First class

(b) Second class

(c) Third class

(d) Fourth class

Correct choice: (a)

Q4: Which of the following is not an element of human biomechanics?

(a) Dynamics

(b) Statics

(c) Systematics

(d) Kinematics

Correct choice: (c)

Q5: Which of the following joint allows the maximum human movement?

(a) Cartilaginous joint

(b) Synovial joint

(c) Fibrous joint

(d) None of the above

Correct choice: (b)