The sit and reach box is a widely used flexibility testing equipment designed to evaluate the flexibility of the hamstrings and lower back muscles. This simple, portable test is conducted by placing the feet against a box and reaching forward as far as possible while keeping the knees touching the floor. The purpose of this test is to assess the range of motion in the lower back and hamstring muscles, which play a crucial role in sports performance, injury prevention, and overall fitness.
How to Conduct the Test
Before conducting the sit and reach test, it is essential to perform a warm-up to prepare the body for the test. The warm-up should include some gentle stretches to loosen the muscles being tested. During the test, the client or patient should sit on the floor or ground with their feet flat against the box, keeping the knees extended. The arms are positioned on top of each other with palms down, and the client reaches forward as far as possible while keeping the hands parallel to the measuring stick or yardstick of the sit and reach box. The score is recorded as the distance reached with the fingertips on the measuring stick.
Test Norms and Variations
The sit and reach test is commonly conducted using specific norms, which vary depending on the age and sex of the individual. For instance, the average score for men aged 18-39 is typically around 15 inches (386 millimeters). However, this value can increase or decrease based on the age of the individual. The sit and reach test can also be conducted bilaterally (on both sides) to obtain a more comprehensive evaluation of the flexibility of the lower back and hamstrings.
Interclass Correlation Coefficient (ICC)
Research has shown that the ICC for sit and reach tests vary based on the population being tested. Overall, the ICC range forICC sit and reach tests is between 0.4 to 0.8, which indicates moderate to good reliability. This means that when the same individuals are tested multiple times, the results are consistent. However, it is essential to note that the ICC does not differentiate between true and false scores, and thus it is crucial to use test-retest reliability when comparing results across different days.
Evidence Review
Lemmink等人（2003）的研究表明，中老年男性和女性的ICC在0.57到0.74之间，这表明测试具有较好的可靠性和有效性。其他研究亦证实了该测试方法的可靠性。例如，Ayala等人（2011）的研究显示，该测试方法的CV为8.74%，而ICC为0.92，这进一步证明了该测试方法的一致性和可靠性。
Useful Information for theTester
As a tester, it is essential to understand how to properly apply the test to ensure its accuracy. Preparing the client/patient for the test is also important to prevent injuries and maximize the accuracy of the test. It is also essential to adjust the measuring stick to account for the variations in arm and leg lengths of the person being tested.
Alternatives to the Sit and Reach Box
For individuals who do not have access to a sit and reach box, using a yardstick or tape measure with a box or stool can be an alternative. Place the nine-inch mark of the measuring stick on the edge of the box where the feet are placed. The person then performs the sit and reach motion as described above. While this method may not provide the same level of detail as the sit and reach box, it still provides a reliable way to assess flexibility of the hamstring and low back muscles.
The sit and reach box is a versatile and practical tool for evaluating the flexibility of the hamstrings and lower back muscles. Whether you are a tester, athlete, or simply someone interested in improving their flexibility, this equipment provides an effective way to measure and compare your flexibility scores over time. The sit and reach box is easy to use, portable, and provides results in inches or centimeters, making it a valuable asset for anyone looking to improve their flexibility.
