For example, if a movement required reaching to touch a target in front of the body, flexion at the shoulder would create a torque at the elbow, while extension of the elbow would create a torque at the wrist. These torques increase as the speed of movement increases and must be compensated and adjusted for to create coordinated movement. This may, therefore, explain decreased coordination at higher movement velocities and accelerations. Dysfunction of the vestibulocerebellum (flocculonodular lobe) impairs balance and the control of eye movements. This presents itself with postural instability, in which the person tends to separate his/her feet upon standing, to gain a wider base and to avoid titubation (bodily oscillations tending to be forward-backward ones). The instability is, therefore, worsened when standing with the feet together, regardless of whether the eyes are open or closed. This is a negative Rombergs test, or more accurately, it denotes the individuals inability to carry out the test, because the individual feels unstable even with open eyes. Dysfunction of the spinocerebellum  (vermis and associated areas near the midline) presents itself with a wide-based "drunken sailor" gait (called truncal ataxia), characterised by uncertain starts and stops, lateral deviations, and unequal steps. As a result of this gait impairment, falling is a concern in patients with ataxia. Studies examining falls in this population show that 74–93% of patients have fallen at least once in the past year and up to 60% admit to fear of falling.
Other tools that assess motor function, balance and coordination are also highly valuable to help the therapist track the progress of their patient, as well as to quantify the patients functionality. These tests include, but are not limited to:

The Berg Balance Scale
Tandem Walking (to test for Tandem gaitability)
Scale for the Assessment and Rating of Ataxia (SARA)
tapping tests – The person must quickly and repeatedly tap their arm or leg while the therapist monitors the amount of dysdiadochokinesia. finger-nose testing – This test has several variations including finger-to-therapists finger, finger-to-finger, and alternate nose-to-finger. Other uses
The term "ataxia" is sometimes used in a broader sense to indicate lack of coordination in some physiological process. Examples include optic ataxia (lack of coordination between visual inputs and hand movements, resulting in inability to reach and grab objects) and ataxic respiration (lack of coordination in respiratory movements, usually due to dysfunction of the respiratory centres in the medulla oblongata). Optic ataxia may be caused by lesions to the posterior parietal cortex, which is responsible for combining and expressing positional information and relating it to movement. Outputs of the posterior parietal cortex include the spinal cord, brain stem motor pathways, pre-motor and pre-frontal cortex, basal ganglia and the cerebellum. Some neurons in the posterior parietal cortex are modulated by intention. Optic ataxia is usually part of Balints syndrome, but can be seen in isolation with injuries to the superior parietal lobule, as it represents a disconnection between visual-association cortex and the frontal premotor and motor cortex.