Extendable Goniometer Chromium Brass 4X Lens Dual 180 Degree Scale

Extendable Goniometer – Chromium-Plated Brass | 4X Magnifying Lens | Dual 180° Scale | Arms Extend 9"–26"

Accurate, versatile joint measurement for large and small joints. This extendable goniometer is constructed of chromium-plated brass for durability and precision, with two stainless steel arms that extend from 9" to 26" to accommodate measurement of both small and large joints in a single instrument. The 4X magnifying lens makes the dual 180-degree high-resolution scale easy to read with precision. The 360-degree arm rotation in both directions with a resistance swivel ensures the arms stay in position during measurement without slipping. Compact, lightweight, and portable for clinical and field use. Total extended length: 22-1/4".

Key Features

• 4X magnifying lens — easy, accurate reading of the dual 180° high-resolution scale
• Dual 180-degree scale — high-resolution markings for precise measurement
• Two stainless steel arms extending 9" to 26" — measures both small and large joints
• Chromium-plated brass construction — durable, corrosion-resistant, and precise
• 360-degree arm rotation in both directions — full range of motion measurement
• Resistance swivel — arms hold position during measurement without slipping
• Smooth precision glide — consistent, repeatable measurements
• Compact, lightweight, and portable
• Total extended length: 22-1/4"

Specifications

• SKU: 10047D
• Construction: Chromium-plated brass body, stainless steel arms
• Arm Range: 9" to 26"
• Total Extended Length: 22-1/4"
• Scale: Dual 180-degree high-resolution
• Lens: 4X magnifying
• Rotation: 360 degrees, both directions
• Swivel: Resistance swivel for arm stability
• Shipping Carton: 9" L x 7" W x 5" H

Ideal For

• Physical therapists and occupational therapists measuring joint range of motion
• Orthopedic and sports medicine clinical assessments
• Measuring large joints — hip, knee, shoulder, elbow
• Measuring small joints — fingers, wrist, ankle, toes
• Documenting ROM progress during rehabilitation
• Portable field use and home health assessments

Frequently Asked Questions

What is a goniometer and how is it used?
A goniometer is a clinical instrument used to measure the range of motion (ROM) of a joint in degrees. The clinician aligns the stationary arm of the goniometer with the proximal body segment (the part of the limb above the joint) and the moving arm with the distal body segment (the part below the joint), with the axis of the goniometer centered over the joint. The angle between the two arms is then read from the scale, providing an objective measurement of how far the joint can move in a given direction. Goniometry is a standard assessment tool in physical therapy, occupational therapy, and orthopedic medicine.

Why does this goniometer have extendable arms?
Standard goniometers have fixed-length arms that work well for small to medium joints but can be difficult to align accurately on large joints like the hip, knee, or shoulder, where the bony landmarks are far apart. The extendable arms on this goniometer stretch from 9" to 26", allowing the clinician to reach distant landmarks on large joints with the same instrument used for small joints. This eliminates the need to carry multiple goniometers of different sizes and ensures consistent measurement technique across all joint sizes.

What does the 4X magnifying lens do?
The 4X magnifying lens is positioned over the scale of the goniometer to make the degree markings easier to read accurately. Goniometer scales are typically small and closely spaced — the magnifying lens enlarges the scale markings so the clinician can read the exact degree measurement without squinting or approximating. This is particularly useful for high-resolution scales where 1–2 degree precision is important for documenting ROM changes over the course of rehabilitation.

What is the resistance swivel and why does it matter?
The resistance swivel is a friction mechanism at the pivot point of the goniometer that provides just enough resistance to hold the arms in position once they are set — preventing them from slipping or closing before the reading is taken. Without resistance, the arms can shift when the goniometer is lifted away from the patient to read the scale, introducing measurement error. The resistance swivel allows the clinician to position the arms on the patient, lift the goniometer, and read the scale accurately without the arms moving during the process.