Sit-and-reach test

Abstract

The Sit-and-reach test is a widely utilized physical fitness assessment designed to measure the static flexibility of the lower back and the length or extensibility of the hamstrings. The procedure requires the individual to sit in a long-sitting position with the feet placed flat against a specialized Sit and Reach box. The subject then reaches forward with both hands toward their toes, applying pressure against the box where a measuring scale is affixed. The resulting score provides a quantitative measure of trunk and posterior leg flexibility, specifically assessing the movement capabilities of the vertebral column and related musculature.

Keywords

Flexibility, Hamstrings, Vertebral column, Lower back, Physical fitness, Musculoskeletal assessment, Sit and Reach box, Extensibility, Range of motion.

Authors

Wells KF, Dillon EK (1952), Vrijkotte S, de Vries S, Jongert T (Dutch Adaptation, 2007).

Purpose

The primary purpose of the Sit-and-reach test is to efficiently assess the degree of static flexibility in the lower back and the posterior thigh musculature. Adequate flexibility in these anatomical regions is critical for maintaining proper posture, facilitating efficient biomechanics, and potentially reducing the risk of musculoskeletal injuries, particularly lower back pain, across the lifespan.

This assessment serves as a quick, reliable, and standardized method for screening individuals, ranging from children to adults, for potential limitations in the range of motion associated with the trunk and the hamstring muscles. The results are frequently used in physical education, sports medicine, and general health screenings to establish baseline flexibility data or track physical changes over time in response to training or rehabilitation programs.

Construct

The Sit-and-reach test fundamentally measures the physiological construct of static flexibility, specifically focusing on the extensibility of the muscle groups responsible for forward trunk flexion. Flexibility, in this context, refers to the absolute range of movement available in a joint or series of joints, which is a key component of health-related physical fitness.

While the test involves the musculoskeletal system, its score reflects the functional capacity of the posterior kinetic chain. Poor performance often indicates tightness in the hamstrings or lower back extensors. Although traditionally accepted as a measure of combined lower back and hamstring flexibility, modern biomechanical research suggests the score is more strongly correlated with hamstring length than with lumbar spine mobility.

Validity

The original Sit-and-reach test (Wells & Dillon, 1952) possesses strong face validity because the physical action directly mirrors the flexibility component being assessed. It has been historically accepted as a standard measure of general trunk and posterior leg flexibility in various fitness batteries.

However, the concurrent validity of the test has been debated. Studies comparing the Sit-and-reach score to direct measures of lumbar flexion (e.g., radiography) or hamstring length (e.g., goniometry) suggest that the test is a more valid predictor of hamstring extensibility. Its validity for assessing pure spinal flexibility is limited and highly dependent on individual anthropometric variables, such as the ratio of leg length to arm length.

Reliability

The Sit-and-reach test demonstrates high reliability when performed under strictly standardized conditions. Both inter-rater reliability (consistency between different testers) and intra-rater reliability (consistency by the same tester) are typically robust, provided that the testing apparatus (the box) is stable and the protocol is followed precisely.

Key factors ensuring reliability include consistent warm-up procedures, strict adherence to the long-sitting starting position, and prevention of bouncing or jerky movements during the reach. The Dutch adaptation (Vrijkotte et al., 2007) aimed to further standardize the protocol for specific regional use, enhancing measurement consistency within the target population.

Factor Analysis

As a single-item performance assessment, the Sit-and-reach test does not undergo traditional internal factor analysis. However, when included in broader physical performance batteries, the test score consistently loads onto a dominant factor identified as “static lower body flexibility” or “posterior chain extensibility.”

This empirical evidence confirms that the test provides a unique, measurable contribution to the overall assessment of physical fitness components. Researchers often use the test results in multivariate analyses to explore the relationship between flexibility and other health outcomes, such as balance, posture, and risk of injury.

Instrument

Test Type: Observational Physical Assessment / Observation

Format: Performance-based test utilizing a standardized Sit and Reach box and metric scale.

Language Available: Original English (1952); Dutch Version (2007).

Population Group: Clinical and General Population (Movement system disorders, Musculoskeletal health).

Age Group: Children and Adults.

Population Details: Applicable for assessment across various age groups involved in physical education, sports, or rehabilitation settings. Focus areas include the Lower extremity and conditions related to the movement apparatus, such as muscle and tendon disorders.

Test Methodology: The participant sits with legs extended and feet flat against the end panel of the Sit and Reach box. Hands are placed together, and the subject slowly reaches forward along the measuring scale as far as possible, holding the maximum reach momentarily. The score is recorded at the furthest point reached, typically measured in centimeters or inches relative to a zero point set at the plane of the feet.

The original PDF documentation for the explanatory form (Toelichtingsformulier) can be downloaded here: Toelichtingsformulier PDF.

The original PDF documentation for the measurement instrument (Meetinstrument) can be downloaded here: Meetinstrument PDF.

Keywords

Musculoskeletal system, Movement system, Lower extremity, Muscular disorders, Physical assessment, Range of motion, Screening tool, Body composition, Exercise physiology.

Authors

Author ORCID Identifier: N/A (Information not provided in source)

Affiliation Email addresses: N/A (Information not provided in source)

Correspondence Address: N/A (Information not provided in source)

Permissions & Fee and Test Year

The original test methodology was established in 1952 by Wells KF and Dillon EK. As a foundational test in physical education and exercise science, the general protocol is often used without specific licensing fees for standard academic or clinical application.

The Dutch adaptation was published in 2007 by Vrijkotte S, de Vries S, and Jongert T. Specific permissions or fees related to the copyrighted 2007 Dutch adaptation materials (the PDF documents referenced above) must be sought directly from the adapting authors or the publishing entity holding the rights to that specific version.

Reference’s

• Wells, K. F., & Dillon, E. K. (1952). The measurement of mobility of specific joints. Research Quarterly. American Association for Health, Physical Education and Recreation, 23(1), 115–124.
• Vrijkotte S, de Vries S, Jongert T (2007). Nederlandse versie van de Sit-and-reach test. (Dutch Adaptation).

Items of the Sit-and-reach test

IMPORTANT: The following scale items must be preserved in their original language and must not be changed in any way.

Door middel van de Sit and Reach test worden de flexibiliteit van de wervelkolom en de lengte/flexibiliteit van de hamstrings gemeten. In langzit wordt met de handen op elkaar richting tenen gereikt, waarbij de voeten tegen een Sit and Reach box geplaatst zijn en op de box een meetlat is bevestigd.