Impact of Vision Loss on Motor Development Motor Development and Characteristics of Students with Visual Impairments Based on Impact of Vision Loss on Motor Development By Chris Strickling

Holistic vs Sequential Learning Seeing the whole picture vs. “stringing beads” of experience to get an approximated understanding of the whole. “Vision helps interpret sound and movement experiences, build motivation and anticipation, and fix the world spatially so that sensory information makes sense.” (Strickling, 1998)

Questions to be asked: What are the common characteristics in the motor patterns of persons with visual impairments? How are they related to visual impairment? Why are they important? What techniques and strategies can TVIs/O&Ms use in working with these problems? As we will discuss…children who are visually impaired are subject to a predictable set of developmental risks. Realize that a child with a visual loss has a much harder time organizing information in their environment. They are forced to piece together information about their world and environment through various sources (tactile contact, movement, other senses, and/or incomplete or visual information and perception.

Decreased Postural Tone Especially in the shoulder girdle and pelvis. Caused by impact of vision loss on early sensory experiences and the development of reflex activity. The trunk and extremities are also often affected.

How is decreased postural tone related to visual impairment? Optical head righting Labyrinthine righting (righting of head and neck based on gravity) Equilibrium responses Labyrinthine righting has to do with the inner ear communicating to the muscles in the neck to orientate the head) Optical head righting is maintaining visual orientation through visual stimulus.

Why is decreased postural tone important? General muscle weakness and the inability to establish stability. Stability of the neck and shoulder girdle especially impacts visual efficiency. Decrease of endurance in performing complex motor skills ---such as reading braille.

Sensory Integration Learning to use all of the senses together to form a meaningfully whole interpretation of the environment. Must combine information from different senses. Movement is a major concern…it initiates tactile contact with environment, and establishes spatial and body awareness. Unfortunately the acquisition of motor skills is delayed due to lack of visual stimuli as a motivator for early movement. Intervention and encouragement at this stage is very imprortant.

Decreased or inaccurate interpretation of proprioceptic information. Proprioception – the ability to perceive and interpret the influence on gravity or pressure on one’s body and awareness of body parts. Learning the connection between the “feel” of a position and the visual appearance of that position is critical.

Decreased or inaccurate interpretation of vestibular information. Vestibular understanding of the movement of one’s body through space. Perhaps THE single most important motor area for persons with visual impairments. Problems with understanding vestibular input contribute to problems with muscle tone, bilateral integration, and midline orientation. Vestibular is more than rocking. Kids enjoy the big movements or rocking or swinging but have difficulty with the fine interpretation of movement

Problems with tactile processing: Tactile defensiveness Avoid tactile contact with novel objects Perform perseverative and non-purposeful actions on objects Reject specific textures and temperatures Others Often takes a long time to overcome. Inhibits exploration of environment especially new items.

Thought to be caused by lack of integration of early protective tactile defenses. Insecurity with environmental exploration. Avoidance of prone positioning. Over protection Tend to stay supine longer and avoid prone position

Problems with gait: Feet wide Pelvis rotated forward Often exhibit exaggerated weight shift because of proprioceptic problems. Deviation of the head from midline.

Shoulders, Arms, and Hands Poor proximal control Weakness of arms and hands Decreased grasp strength Delayed development of pincer grasp

Problems crossing midline Poorly developed arch of the hand due to lack of arm weight bearing and manipulation of objects Limitation or late development of wrist rotation Inefficient hand manipulation

Legs and Feet External rotation from the hip Widened base of support Duck footed

Positioning Stability is critical to efficient visual functioning. Especially true of the shoulder girdle.

Flicking Causes EEG changes that either calm or excite the central nervous system Those with injuries or disease processes closer to the brain exhibit more mannerisms. Blindism that also is isolating socially. Some kids do much better with a cue or a touch to remind them to stop the behavior rather than telling them to stop or calling attention to the behavior. Redirect, substitute activity, or ignore (especially if the student uses the activity to get attention or disrupt class. Whatever you do that works should be shared and adopted by all care providers and teachers....ask and communicate and include parents (they are experts too)

For more information on this topic, see: Strickling, C. (1998). Impact of vision loss on motor Development: Information for Occupational and Physical Therapists working with visual impairments. Austin, TX: Texas School for the Blind and Visually Impaired. http://www.tsbvi.edu