NHANES National Youth Fitness Survey

NNYFS 2012 Data Documentation, Codebook, and Frequencies

Plank (Y_PLX)

Data File: Y_PLX.xpt

First Published: September, 2013

Last Revised: NA

Locator Record

Title: Plank (Y_PLX )
Contact Number: 1-866-441-NCHS
Years of Content: 2012
First Published: September, 2013
Revised: NA
Access Constraints: None
Use Constraints: None
Geographic Coverage: National
Subject: The plank is an exercise that measures core muscular endurance. Participants aged 3-15 years were eligible for the plank test. Participants got into the plank position and held it for as long as possible without arching their back or letting their hips drop towards the floor. The number of seconds the plank position was held was recorded.
Record Source: NNYFS 2012
Survey Methodology: NNYFS 2012 is a stratified multistage probability sample of the non-institutionalized population aged 3 to 15 years in the U.S.
Medium: NHANES Web site; SAS transport files

Component Description

The Plank is an isometric exercise that works core muscles around the trunk and pelvis. This exercise measures core muscular endurance. Good core strength improves balance and stability and helps to prevent lower back injury. Strong core muscles make it easier to do most physical activities. The plank exercise requires no movement.

Eligible Sample

Participants aged 3-15 years who do not meet any of the exclusion criteria were eligible for this component. Participants were excluded from this component if they had musculoskeletal or neurological problems with either arm or shoulder.

Protocol and Procedure

Trained examiners explained the plank exercise to the participants and showed them a poster of the correct plank position.

Participants were instructed to lie face down on the mat resting on their elbows with their hands on the floor and their toes curled under their feet so that some of their weight was on the balls of their feet. Then they were told to tighten their stomach muscles and the muscles along the front of their thighs. Next, they were told to push off the floor and rise up onto their toes, keeping their elbows on the floor and their back straight.

Participants were instructed to hold this position for as long as they could without letting their hips drop towards the floor or their knees bend. They were given one practice plank test before beginning the measured test. Participants were instructed to correct their position if they wobbled or moved out of position during the measured test. If it happened a second time the test was stopped. The test ended either when participants could no longer maintain the correct position, or when they requested the test be stopped.

The number of seconds the plank position was held was recorded.

Refer to the procedures manual for a detailed description of the plank body testing procedure (http://www.cdc.gov/nchs/nnyfs/manuals.htm).  

Quality Assurance & Quality Control

Examiners were trained in administering this component prior to the start of the NHANES National Youth Fitness Survey, and quality control checks were made during field visits by NHANES and survey operations staff.

Data Processing and Editing

Edits were made where necessary to ensure the completeness, consistency, and analytic usefulness of the data.

Analytic Notes

Component status code: A final plank status code (PLSTS) provides analysts with a quick method of identifying survey participants who have completed the plank exam.

Comment Codes: Comment codes (PLCMT) were added by the examiners, during data collection, to document problems or situations that arose during the plank measurement test. These comments indicate reasons why a participant may not have completed the plank test. Analysts should review the comment code information for the plank prior to data analysis.

There are 118 participants with a complete status code (PLSTS=1) and a comment code “could not obtain” (PLCMT=2). These codes indicate that they attempted the exam but were not able to hold the correct position to be measured, therefore there is no measured result recorded for them (MPXPLANK=missing). Of these 118 participants, 111 were children 3-5 years old and may have had difficulty understanding the instructions to perform the plank, or may not have been physically or behaviorally mature enough to carry out the correct position for the exam.

Sample Weights: The NNYFS examination sample weights should be used to analyze the plank data. Please refer to the NNYFS Analytic Guidelines for details on the use of sample weights and other analytic issues.

References

N/A.

Codebook and Frequencies