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Cooling Induces Motor Facilitation With Sympathetic Activation

Brief Skin Cooling Induces Muscle Spindle Sensitivity With Heightened Sympathetic Outflow

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05832970
Enrollment
11
Registered
2023-04-27
Start date
2023-04-03
Completion date
2023-04-08
Last updated
2023-04-27

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Cryotherapy Effect

Keywords

muscle spindle, sympathetic outflow, motor facilitation

Brief summary

Cryotherapy has beneficial effects such as motor facilitation, increase isometric force generation, and reduce spasticity. It is known that the muscle spindle has sympathetic innervation. Muscle spindle sensitivity increase with sympathetic activity. This research has three hypotheses: First, short-term cold application to the skin increases sympathetic activity. Second, there is an increase in muscle spindle sensitivity with increased sympathetic activity. Third, the effect of short-term cold on muscle spindle sensitivity continues until the skin temperature returns to normal. The purpose of this research is to test these hypotheses.

Detailed description

Cryotherapy is a frequently used treatment method in sports medicine and rehabilitation due to its beneficial neuromuscular effects. Its main beneficial effects are motor facilitation, increase isometric force generation, and reduce spasticity. The motor effects of cryotherapy may differ depending on the duration of application, the coolant used agent (ice, ice water, coolant spray, etc.), and the thickness of the subcutaneous adipose tissue. The short-term cold application increases the force of contraction with motor facilitation. As the cold application period gets longer, the effects of the cold that inhibit motor functions such as gamma motor neuron inhibition, muscle spindle inhibition, and muscle conduction block come to the fore. It is known that the muscle spindle has sympathetic innervation. It has been reported in recent studies that mental arithmetic, cold application to the skin, isometric contraction of remote muscles, and ischemia increase muscle spindle sensitivity through increased sympathetic activity. However, there are very limited studies showing that cold application increases muscle spindle sensitivity through increased sympathetic activity. On the other hand, in terms of determining treatment and rehabilitation strategies, it is important to know how long the effect of the cold application on muscle spindle sensitivity continues. However, it is not clear how long the effect of the cold application on muscle spindle sensitivity lasts after the cold application ends. There is a widespread belief that the motor facilitation effect of cryotherapy can occur with the stimulation of cutaneous cold receptors. Considering this view, it can be thought that the effect of the short-term cold application on muscle spindle sensitivity continues until the skin temperature returns to normal. This research has three hypotheses: First, short-term cold application to the skin increases sympathetic activity. Second, there is an increase in muscle spindle sensitivity with increased sympathetic activity. Third, the effect of short-term cold on muscle spindle sensitivity continues until the skin temperature returns to normal. The purpose of this research is to test these hypotheses.

Interventions

OTHERBrief skin cooling

Brief skin cooling will be applied to the hand using the cold-bath immersion

Sponsors

Istanbul Physical Medicine Rehabilitation Training and Research Hospital
Lead SponsorOTHER_GOV

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE

Eligibility

Sex/Gender
MALE
Age
20 Years to 45 Years
Healthy volunteers
Yes

Inclusion criteria

* Being healthy * Being a young adult (20-45 years old) * Volunteer

Exclusion criteria

* Scar, dermatitis, etc. in the skin tissue where the superficial electromyography electrode will be placed * Upper extremity bone and joint disease, history of neuromuscular disease * Heart disease, Hypertension * Cold intolerance

Design outcomes

Primary

MeasureTime frameDescription
Change from baseline in Soleus H-reflexBaseline (pre-cold pressor test) and 0, 3, 6, 9, 12, 15 minutes post-cold pressor testBy stimulating the tibial nerve with an electrical current, the Soleus H-reflex will be obtained. Its peak to peak amplitude will be measured in microvolts.
Change from baseline in T-reflexBaseline (pre-cold pressor test) and 0, 3, 6, 9, 12, 15 minutes post-cold pressor testSoleus T-reflex will be obtained by hitting the Achilles tendon with the electronic reflex hammer. Its peak to peak amplitude will be measured in microvolts.
Change from baseline in Heart rateBaseline (pre-cold pressor test) and 0, 3, 6, 9, 12, 15 minutes post-cold pressor testHeart rate will be monitored with DII derivation electrocardiographic recording.Heart rate will be reported as beats per minute.

Secondary

MeasureTime frameDescription
Skin temperatureBaseline (pre-cold pressor test) and 0, 3, 6, 9, 12, 15 minutes post-cold pressor testThe skin temperature of the back of the hand exposed to the cold application will be measured with an infrared thermometer and the results will be reported in degrees Celsius.

Countries

Turkey (Türkiye)

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026