<unk>  (UMNS) is the<unk>  control changes that can occur in skeletal muscle after an<unk><unk><unk>  lesion. Following<unk><unk><unk>  lesions, affected muscles potentially have many features of altered performance including: *weakness (decreased ability for the muscle to generate force) *decreased<unk>  control including decreased speed, accuracy and dexterity *altered muscle tone (hypotonia or hypertonia) – a decrease or increase in the baseline level of muscle activity *decreased endurance *exaggerated deep tendon reflexes including spasticity, and clonus (a series of involuntary rapid muscle contractions) Such signs are collectively termed the<unk> ". Affected muscles typically show multiple signs, with severity depending on the degree of damage and other factors that influence<unk>  control. In<unk> natomical circles, it is often joked, for example, that hemisection of the cervical spinal cord leads to an<unk>  lower<unk><unk>  syndrome and a lower<unk> ". The saying refers to lower<unk><unk>  symptoms in the<unk>  extremity (arm) and<unk><unk><unk> s symptoms in the lower extremity (leg). Health professionals' understanding of impairments in muscles after an<unk><unk><unk>  lesion has progressed considerably in recent decades. However, a diagnosis of "spasticity" is still often used interchangeably with<unk> , and it is not unusual to see patients labeled as spastic who demonstrate an array of UMN findings. Spasticity is an exaggerated stretch reflex, which means that a muscle has a reflex contraction when stretched, and that this contraction is stronger when the stretch is applied more quickly. The commonly quoted definition by Lance (1980) describes "a<unk>  disorder, characterised by a velocity-dependent increase in tonic stretch reflexes with exaggerated tendon jerks, resulting from hyper-excitability of the stretch reflex as one component of the<unk><unk><unk> e <unk> ". Spasticity is a common feature of muscle performance after<unk><unk><unk>  lesions, but is generally of much less clinical significance than other features such as decreased strength, decreased control and decreased endurance. The confusion in the use of the terminology complicates assessment and treatment planning by health professionals, as many confuse the other findings of<unk>  and describe them as spasticity. This confusion potentially leaves health professionals attempting to inhibit an exaggerated stretch reflex to improve muscle performance, potentially leaving more significant UMNS changes such as weakness unaddressed. Improved understanding of the multiple features of the<unk>  supports more rigorous assessment, and improved treatment planning.
Upper motor neuron syndrome
Motor neuron disease
Distal hereditary motor neuronopathies
Central cord syndrome
Vascular myelopathy
Occipital horn syndrome
Posterior cord syndrome
Tethered spinal cord syndrome