Relationship Between 2D:4D Finger Ratio and Proprioception

NCT06953219 | Completed

• 1 other identifier: 2025/405
• Study Type: observational
• Target: 88
• Locations: 1 country
• Sites: 1

Brief Summary

Background: 2D:4D ratio (the ratio of the length of the second digit to the length of the fourth digit) has been reported to be associated with muscle strength and physical performance, numerical competencies, spatial skills and cognitive abilities. However, the relationship between 2D:4D ratio and proprioception is not well-known, which was therefore aimed at investigating in current study. Methods: 2D:4D ratio (electronic digital calliper) and proprioception (Join position error is measure with Cervical Range of Motion instrument) were assessed in all individuals (n=35.7 ± 11.2 years).

Conditions

Proprioception

Keywords

digit ratio; proprioception

Outcome Measures

Primary Outcomes (4)

• Finger length measurement and 2D:4D ratio calculation

  The lengths of the second (2D) and fourth (4D) fingers on each hand were measured using an electronic digital caliper with a precision of 0.01 millimeters. Measurements were taken on the palmar surface of the hand, extending from the distal tip of the finger to the basal crease at the proximal end of the digit.The 2D:4D ratio was calculated separately for the right and left hands. To enhance the accuracy of the 2D:4D ratio measurements, each finger was measured three times during a single assessment session by the same investigator. The repeated measurements were not taken consecutively; instead, at least one other hand was measured between the first and second measurements of any given hand. This procedure was implemented to minimize the potential influence of recall bias on subsequent measurements.

  baseline

• Cervical Range of Motion

  The cervical range of motion measurement was performed using a Cervical Range of Motion (CROM) device, which is a reliable and valid tool. The CROM unit is a mechanical instrument that measures cervical ranges by combining a magnetic reference with standard inclinometers. The individuals were told to sit comfortably with their hands on the armrest and their backs straight on the chair. The CROM unit was secured on the individuals' head by the physiotherapist. The CROM unit's magnetic yoke is positioned squarely around the neck with its arrow pointing directly north. Afterwards, physiotherapist asked individuals to perform cervical range of motion in all three directions: flexion- extension, lateral flexion and rotation.The maximum range of cervical flexion, extension, left and right rotation, and left and right lateral flexion was measured three times and averaged.

  baseline

• Repositioning to neutral head position (NHP)

  For the NHP assessment, the individuals were asked to keep their head in the neutral head position, with their eyes closed. The deviations from the neutral (0) position in the sagittal (flexion-extension), frontal (lateral flexion), and transverse (rotation) planes were recorded using the CROM device.

  baseline

• Repositioning the head to a predetermined reference point (Target Head Position, THP)

  For the assessment of THP, the target position will be defined as half of the maximum active range of motion measured during a standard cervical joint mobility assessment. While the patient's eyes are covered with an eye mask, the head will first be slowly positioned by the physiotherapist to the predetermined target angle and held in this position for five seconds for the patient to perceive. Subsequently, the head will be moved away from the target position, and the patient will be asked to actively reposition it to the original target. Each measurement will be repeated three times, and the mean deviation from the target angle will be recorded. Measurements will be conducted separately for flexion, extension, right rotation, left rotation, right lateral flexion, and left lateral flexion

  baseline

Study Arms (1)

assessment group

Finger length measurements(second digits and fourth digit) were made with acaliper. Range of motion (ROM) and joint position error measuremenst were made with a CROM device. Joint position error is assessed with neutral head positioning test and target head positioning test.

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Healthy adult individuals aged between 18 and 65 years, who volunteered to participate in the study. Participants had no sensory loss or severe neurological disorders affecting proprioception. Individuals with hand or cervical trauma history, congenital hand anomalies, or any condition preventing accurate 2D:4D measurement were excluded.

You may qualify if:

• Age between 18 and 65 years
• Agreeing to participate in the study.

You may not qualify if:

• Individuals who have scars, finger deformities, and/or surgical interventions that would prevent accurate measurement of the 2D:4D ratio
• Congenital hand anomalies
• History of trauma involving the hand or cervical region were excluded from the study.
• Having sensory loss or severe neurological disorder that would affect proprioception

Sponsors & Collaborators

• Izmir Democracy University: lead

Study Sites (1)

Izmir Democracy University

Izmir, Izmır, 35140, Turkey (Türkiye)

Location

Study Officials

• Onur Engin, Assist Prof

  Izmir Democracy University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Dr.

Study Record Dates

• First Submitted: April 22, 2025
• First Posted: May 1, 2025
• Study Start: January 29, 2025
• Primary Completion: March 24, 2025
• Study Completion: April 9, 2025
• Last Updated: May 1, 2025

Record last verified: 2025-04

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)