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Differential Assessment of Hypertonia

Not Applicable
Recruiting
Conditions
SCI - Spinal Cord Injury
PD - Parkinson's Disease
Interventions
Procedure: Continuous passive motion device (CPM) of ankle
Registration Number
NCT06596187
Lead Sponsor
Chang Gung University
Brief Summary

Spasticity and rigidity are common symptoms of central nervous system injuries, such as spinal cord injury and Parkinson's disease, and result in distinct patterns of increased resistance during passive joint movements. Spasticity is characterized by a velocity-dependent increase in stretch reflexes, accompanied by exaggerated tendon responses, while rigidity is marked by consistent resistance throughout the range of motion, traditionally considered independent of stretch velocity. However, recent studies suggest that rigidity may also be influenced by stretch velocity. This study aims to investigate muscle tone by examining spasticity, rigidity, and normal muscle function through neural and biomechanical changes. Standard clinical tools, such as the Modified Ashworth Scale and Unified Parkinson's Disease Rating Scale, along with additional assessments like the Myoton and Post-Activation Depression (PAD), will be employed.

Detailed Description

Spasticity and rigidity are common symptoms resulting from central nervous system injuries (e.g., spinal cord injury and Parkinson's disease). During passive joint movement, spasticity and rigidity manifest as two distinct patterns of increased resistance. Spasticity is a type of hypertonia characterized by a stretch reflex that increases with speed, accompanied by exaggerated tendon reflexes. Rigidity, on the other hand, is another form of hypertonia, where resistance increases during passive movement and remains consistent throughout the range of motion.

The degree of rigidity is traditionally considered independent of stretch velocity, which is one of the key differences from spasticity. However, recent studies have found that rigidity may also increase with stretch velocity. Despite attempts to distinguish different types of hypertonia based on stretch velocity, these efforts have largely been unsuccessful. Many factors influence muscle tone, which can be broadly categorized into changes in neural and biomechanical properties. The Modified Ashworth Scale and the Unified Parkinson's Disease Rating Scale are the most commonly used clinical tools for assessing spasticity and rigidity. Additionally, devices such as the Myoton or laboratory parameters like Post-Activation Depression (PAD) are also used for assessment.

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
45
Inclusion Criteria
  • Clinical diagnosis of Parkinson disease.
Exclusion Criteria
  1. Musculoskeletal injuries on legs
  2. Osteoporosis.
  3. Any peripheral or central nervous system injury or disease patients.

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Healthy ParticipantsContinuous passive motion device (CPM) of ankleTo establish the relationship between changes in foot pressure during ankle joint movement, muscle tone, and Post-Activation Depression (PAD).
PD PatientsContinuous passive motion device (CPM) of ankleTo establish the relationship between changes in foot pressure during ankle joint movement, muscle tone, and Post-Activation Depression (PAD).
SCI PatientsContinuous passive motion device (CPM) of ankleTo establish the relationship between changes in foot pressure during ankle joint movement, muscle tone, and Post-Activation Depression (PAD).
Primary Outcome Measures
NameTimeMethod
H-reflex AmplitudeBefore CPM, immediately after CPM

The peak-to-peak amplitude of the H-reflex measured in the soleus muscle to assess spinal motor neuron excitability. Unit: Millivolts (mV)

M-wave AmplitudeBefore CPM, immediately after CPM

The peak-to-peak amplitude of the M-wave recorded in the soleus muscle to assess peripheral motor neuron excitability and muscle response. Unit: Millivolts (mV)

Level of Post-Activation Depression (PAD) of the H-reflex.Before CPM, immediately after CPM

The H-reflex will be elicited by electrical stimulation of the tibial nerve (or other motor nerves), and PAD will be assessed by measuring the reduction in H-reflex amplitude following a series of repetitive stimuli. The amplitude of the H-reflex after repeated stimulation will be compared to the baseline single stimulus.

H/M ratioBefore CPM, immediately after CPM

The H/M ratio is calculated by dividing the amplitude of the H-reflex by the amplitude of the M-wave.

Muscle Tone (Frequency, Hz)Before CPM, immediately after CPM

This parameter measures the natural oscillation frequency of the muscle in response. It reflects the muscle's state of tension or readiness

Elasticity (Dynamic Stiffness, N/m)Before CPM, immediately after CPM

Elasticity, measured in Newtons per meter, reflects the muscle's ability to return to its original shape after being deformed by the impulse

Stiffness (Decay, ms)Before CPM, immediately after CPM

This parameter quantifies the rate at which the muscle returns to its initial state after the impulse, indicating the muscle's stiffness.

Mechanical Stress (Creep, s) and Relaxation (S)Before CPM, immediately after CPM

These parameters measure the time it takes for muscle tissue to adapt to a sustained force (creep) and the time it takes for the muscle to return to a relaxed state after removing the force (relaxation)

Plantar foot pressure distribution and peak pressureMeasured continuously during CPM

Foot pressure will be measured using a pressure sensors during ankle movement.

Secondary Outcome Measures
NameTimeMethod
M-wave LatencyBefore CPM, immediately after CPM

The time from the onset of electrical stimulation to the onset of the M-wave response in the soleus muscle, used to assess changes in peripheral nerve conduction velocity. Unit: Milliseconds (ms)

Trial Locations

Locations (1)

Chang Gung University

🇨🇳

Taoyuan, Taiwan

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