Lecture 7 - Coordination and Balance Flashcards
What is coordination
- The ability to execute smooth, accurate, controlled movement
- coordinated movement involves multiple joints and muscles that are activated at the appropriate time with the correct amounts of force so that tooth, efficient and accurate movements occur
- essential in sequencing, timing, and grading
Dexterity
Skillful use of the fingers during fine motor tasks
Agility
ability to readily and smoothly initiate, stop, or modify movements while maintaining postural control
Center of mass (COM)
The midpoint of the body mass; in erect standing posture, the COM is located at the level of the second sacral segment
Base of support (BOS)
Refers to the area beneath a person that includes every point of contact that the person makes with the supporting surface
Balance
The condition in which all the forces acting on the body are balanced such that the centre of mass (COM) is within the stability limits, the boundaries of the base of support (BOS)
Sensory integration into postural control
- The sensory system provide the CNS with important information about postural control and balance, including information about the results of our own actions and the surrounding environment
- Includes vision, somatosensory, and vestibular
Visual system
The visual system serves as an important source of information for the ability to perceive movements and detect the relative orientation of body segment sand orientation of the body in space (visual proprioception)
Focal vision
- Cognitive/ explicit
- plays a major role in localizing feature in the environment and in our conscious reaction to visual events
Ambient vision
- Sensorimotor/implicit
- Utilizes the entire visual field to provide information on the location;izing features about the environment and to guide movements using largely nonconscious awareness
Optic ataxia
The patient can recognize an object using focal vision but cannot use visual information to accurately guide the hand to the object (impaired ambient vision)
Visual agnosia
The patient cannot recognize common objects, but can use ambient visual system to reach and grasp an object or navigate an environment
Somatosensory system
inputs include the cutaneous and pressure sensations from the body segments in contact with the support surface and muscle and joint proprioception throughout the body
Example of a somatosensory system
Light touch contact from the hands on a stable surface is also used as a balance aid, provides information about the relative orientation and movement of the body in relation to the support surface
Vestibular system
- Stabilizes gaze during head movements via the vestibulo-ocular reflex (VOR)
- Assists in the regulation of postural tone and postural muscle activation via the vestibule-spinal reflex (VSR)
Semicircular canals (SCC)
Detects angular acceleration and deceleration forces acting on the head and are sensitive to fast (phasic) movements of the head
Otolith organs
Detect linear acceleration and orientation of the head with reference to gravity and response to slow head movements and positional chance referenced to gravity
Peripheral motor system
Somatice Motor System includes muscles, joints, and their sensory and motor innervation
Central motor system
- Divided into three hierarchical levels
- This does not imply a strictly top-down control of coordinated movement as each level of the nervous system can influence other levels depending on task demands