Ignite Creation Date:
2024-06-16 @ 11:50 AM
Last Modification Date:
2024-10-26 @ 3:31 PM
Study NCT ID:
NCT06442956
Status:
NOT_YET_RECRUITING
Last Update Posted:
2024-06-05
First Post:
2024-05-29
Brief Title:
Effect of Rapid Heat Stress on Firefighters Musculoskeletal Injury Risk
Sponsor:
Louisiana State University Health Sciences Center Shreveport
Organization:
Louisiana State University Health Sciences Center Shreveport
Study Overview
Official Title:
The Impact of Rapid Heat Stress on Firefighters Strength Dynamic Balance and Movement Quality
Status:
NOT_YET_RECRUITING
Status Verified Date:
2024-06
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
This study will examine the effect of heat stress on factors that influence musculoskeletal injury risk in firefighters Participants will attend 4 data collection sessions 1 informed consent screening and familiarization 2 pre-tests strength balance and movement quality 3 heat stress rapid or gradual followed by post-tests strength balance and movement quality 4 heat stress rapid or gradual followed by post-tests
Detailed Description:
This study utilizes a crossover design with participants acting as their own controls and participating in both the control gradual uncompensable heat and experimental rapid heat stress RHS conditions The independent variable is the type of heat stress uncompensable or rapid The dependent variables are peak concentric muscle torque hip abductors hip adductors knee flexors knee extensors dynamic balance Y-Balance Test Firefighter-Specific Functional-Balance Test FFSFBT and frontal plane movement quality Forward-Step-Down Test FSDT These will be measured three times once during pre-testing and twice during post-testing as described below
The study will consist of four visits Visit one will be the informed consent and familiarization to the outcome measures Participants will be educated on filling out the 24-hour fooddrink diary and asked to standardize their diet as close as possible to this record the 24 hours before visits 2 3 and 4 Injury history and demographic data will be collected at visit 1
Visit two will be the pre-test data collection which will occur at approximately 22C Participants will complete all outcome measures torque balance movement quality measures Body composition will also be measured in the BodPod at this time
Before visits 2 3 and 4 participants will follow the safety guidelines outlined below to ensure proper hydration
48 hours before no heat stress will contact participant to determine if they have been called out to a live fire Data collection will be postponed if so
24 hours before no alcohol consumption no energy drink consumption normal coffeetea is allowed
24 hours before no physical activity exercise or vigorous play
24 hours before drink 37L of total water to make sure to be well-hydrated
2 hours before eat last meal
Visits three and four will consist of a steady-state treadmill protocol inside the environmental chamber 37-38C 50 humidity followed by post-test measures During either session three or four the participant will don hisher firefighting gear jacket pants hood boots gloves and perform the treadmill test with the gear on This is the RHS trial and will be denoted GEAR In the other session the participant will wear exercise clothes shirt and shorts plus a weighted backpack to replicate the weight of the gear This is the gradual uncompensable heat stress trial and will be denoted NOGEAR The order of the GEAR and NOGEAR sessions will be randomized and counterbalanced to prevent crossover effects
Upon arrival for the pre-testing visit session two participants will be measured for height using a stadiometer and weight Body composition will be measured once with the BodPod Cosmed USA They will warm up for five minutes on an exercise bike or treadmill then proceed with taking the outcome measures
Upon arrival for visits three and four participants will be weighed again A urine sample will be collected to assess hydration status They will swallow the core temperature Tc capsule 40-45 minutes prior to the start of the session using a small amount of 20C water with no further water ingestion throughout the protocol to avoid artificially lowering Tc Participants will be fit with the Equivital EQLife Monitor Equivital NY system to record heartrate HR and Tc They will then perform the treadmill protocol and post-test measures will be completed immediately following the cessation of the treadmill test with removal of their gear They will be weighed following exercise to determine changes in body weight due to sweating
Sessions three and four will be separated by at least seven days to reduce the influence of heat acclimatization and fatigue Continuous monitoring of Tc and HR will help ensure participant safety
The treadmill exercise protocol begins with a graded approach to reach aerobic steady state The treadmill protocol includes an initial five-minute stage at 3 miles per hour and a 0 grade followed by increases in percent grade of 4 at minute 5 and 8 at minute 10 and continued throughout the test Following the final planned incremental increase in treadmill incline the incline will then be adjusted to ensure that the subject remains at steady-state for the duration of the protocol defined by a respiratory exchange ratio between 09-099 using the labs metabolic cart Parvomedics USA HR rating of perceived exertion RPE thermal comfort and thermal sensation will be recorded at each 05C interval The treadmill test will be stopped when participants either reach a Tc of 39C or a volitional maximum participant is unable to continue exercise The investigators will also halt the test if signs of excessive heat stress are present unsteady gait confusion dizziness slurred speech etc Should the participant not meet either termination criteria there will be a 50 minute time limit for the treadmill protocol for the GEAR condition and 2 hour limit for the NOGEAR condition Both GEAR and NOGEAR sessions will begin with the same treadmill test
Following the treadmill test the participants will complete the post-test outcome measures These consist of isokinetic torque of the hip abductors and adductors isokinetic torque of the knee flexors and extensors the Y-Balance Test the FFSFBT and FSDT Participants will doff their gear immediately following cession of the treadmill test For unilateral tests the dominant leg will be recorded and used for these tests this is the leg used to kick a ball Outcome measure order will be standardized for each participant with testing order based on primary outcomes and difficulty of each test The FSDT will be performed first as this is the primary outcome and previous research showed that recovery after a maximal exertion stimulus happens quickly The FFSFBT will be performed next followed by the Y-Balance Test Isokinetic testing will be last due to the fatiguing nature of this testing Hip muscles will be tested first followed by thigh muscles Three minutes will be allotted for rest and instruction between each outcome measure Five minutes of rest will be given between isokinetic tests to allow for machine set-up and instructions One minute of rest will be given between each isokinetic speed with three speeds tested for the hip 30 60 and 120 per second and knee 60 180 and 300 per second muscles
Participants will be followed for 2 years with 6-month follow-up calls to track injury status Details on type of injury location of injury and time lost to work will be collected
The study will consist of four visits Visit one will be the informed consent and familiarization to the outcome measures Participants will be educated on filling out the 24-hour fooddrink diary and asked to standardize their diet as close as possible to this record the 24 hours before visits 2 3 and 4 Injury history and demographic data will be collected at visit 1
Visit two will be the pre-test data collection which will occur at approximately 22C Participants will complete all outcome measures torque balance movement quality measures Body composition will also be measured in the BodPod at this time
Before visits 2 3 and 4 participants will follow the safety guidelines outlined below to ensure proper hydration
48 hours before no heat stress will contact participant to determine if they have been called out to a live fire Data collection will be postponed if so
24 hours before no alcohol consumption no energy drink consumption normal coffeetea is allowed
24 hours before no physical activity exercise or vigorous play
24 hours before drink 37L of total water to make sure to be well-hydrated
2 hours before eat last meal
Visits three and four will consist of a steady-state treadmill protocol inside the environmental chamber 37-38C 50 humidity followed by post-test measures During either session three or four the participant will don hisher firefighting gear jacket pants hood boots gloves and perform the treadmill test with the gear on This is the RHS trial and will be denoted GEAR In the other session the participant will wear exercise clothes shirt and shorts plus a weighted backpack to replicate the weight of the gear This is the gradual uncompensable heat stress trial and will be denoted NOGEAR The order of the GEAR and NOGEAR sessions will be randomized and counterbalanced to prevent crossover effects
Upon arrival for the pre-testing visit session two participants will be measured for height using a stadiometer and weight Body composition will be measured once with the BodPod Cosmed USA They will warm up for five minutes on an exercise bike or treadmill then proceed with taking the outcome measures
Upon arrival for visits three and four participants will be weighed again A urine sample will be collected to assess hydration status They will swallow the core temperature Tc capsule 40-45 minutes prior to the start of the session using a small amount of 20C water with no further water ingestion throughout the protocol to avoid artificially lowering Tc Participants will be fit with the Equivital EQLife Monitor Equivital NY system to record heartrate HR and Tc They will then perform the treadmill protocol and post-test measures will be completed immediately following the cessation of the treadmill test with removal of their gear They will be weighed following exercise to determine changes in body weight due to sweating
Sessions three and four will be separated by at least seven days to reduce the influence of heat acclimatization and fatigue Continuous monitoring of Tc and HR will help ensure participant safety
The treadmill exercise protocol begins with a graded approach to reach aerobic steady state The treadmill protocol includes an initial five-minute stage at 3 miles per hour and a 0 grade followed by increases in percent grade of 4 at minute 5 and 8 at minute 10 and continued throughout the test Following the final planned incremental increase in treadmill incline the incline will then be adjusted to ensure that the subject remains at steady-state for the duration of the protocol defined by a respiratory exchange ratio between 09-099 using the labs metabolic cart Parvomedics USA HR rating of perceived exertion RPE thermal comfort and thermal sensation will be recorded at each 05C interval The treadmill test will be stopped when participants either reach a Tc of 39C or a volitional maximum participant is unable to continue exercise The investigators will also halt the test if signs of excessive heat stress are present unsteady gait confusion dizziness slurred speech etc Should the participant not meet either termination criteria there will be a 50 minute time limit for the treadmill protocol for the GEAR condition and 2 hour limit for the NOGEAR condition Both GEAR and NOGEAR sessions will begin with the same treadmill test
Following the treadmill test the participants will complete the post-test outcome measures These consist of isokinetic torque of the hip abductors and adductors isokinetic torque of the knee flexors and extensors the Y-Balance Test the FFSFBT and FSDT Participants will doff their gear immediately following cession of the treadmill test For unilateral tests the dominant leg will be recorded and used for these tests this is the leg used to kick a ball Outcome measure order will be standardized for each participant with testing order based on primary outcomes and difficulty of each test The FSDT will be performed first as this is the primary outcome and previous research showed that recovery after a maximal exertion stimulus happens quickly The FFSFBT will be performed next followed by the Y-Balance Test Isokinetic testing will be last due to the fatiguing nature of this testing Hip muscles will be tested first followed by thigh muscles Three minutes will be allotted for rest and instruction between each outcome measure Five minutes of rest will be given between isokinetic tests to allow for machine set-up and instructions One minute of rest will be given between each isokinetic speed with three speeds tested for the hip 30 60 and 120 per second and knee 60 180 and 300 per second muscles
Participants will be followed for 2 years with 6-month follow-up calls to track injury status Details on type of injury location of injury and time lost to work will be collected
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
False
Is a FDA Regulated Device?:
False
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
False
Is an FDA AA801 Violation?:
None