Editing Goniometer (section)

===Rehabilitative therapy===
In physical therapy, occupational therapy, Orthotics and prosthetics and athletic training, a goniometer measures [[range of motion]] of limbs and joints of the body. These measurements help accurately track progress in a rehabilitation program. When a patient has decreased range of motion, a therapist assesses the joint before performing an intervention, and continues to use the tool to monitor progress. The therapist can take these range of motion measurements at any joint. They typically require knowledge about the anatomy of the body, particularly bony landmarks. For example, when measuring the knee joint, the therapist places the axis (point of rotation) on the lateral [[epicondyle]] of the femur, and lines up the stationary arm with the [[greater trochanter]] of the [[femur]]. Finally, the therapist lines up the moveable arm of the goniometer with the lateral [[malleolus]] of the [[fibula]], and records a measurement using the degree scale on the circular portion of the tool. Reading [[accuracy]] is sometimes a problem with goniometers. Issues with the intra-measure (between measures) and inter-tester (between clinicians) [[Reliability (statistics)|reliability]] may increase as the experience of the examiner decreases. Some studies suggest that these errors can be anywhere between 5 and 10 degrees.{{citation needed|date=June 2016}}

These goniometers come in different forms that some argue increase reliability.<ref>{{cite journal|last1=Milanese|first1=Gordon|title=Reliability and concurrent validity of knee angle measurement: Smart phone app versus universal goniometer used by experienced and novice clinicians|journal=Manual Therapy|volume=5|pages=1–6}}</ref><ref>{{cite journal|last1=Jones|first1=Sealey|title=Concurrent validity and reliability of the simple goniometer iPhone app compared with the universal goniometer|journal=Physiotherapy: Theory and Practice|volume=30|issue=7|pages=512–516|doi=10.3109/09593985.2014.900835|pmid=24666408|hdl=2328/37026|year=2014|s2cid=28719817|url=https://dspace.flinders.edu.au/xmlui/bitstream/2328/37026/1/Jones_Concurrent_AM20.pdf|hdl-access=free}}</ref> The universal standard goniometer is a plastic or metal tool with 1 degree increments. The arms are usually not longer than 12-inches, so it can be hard to accurately pinpoint the exact landmark for measurement. The telescopic-armed goniometer is more reliable—with a plastic circular axis like a classic goniometer, but with arms that extend to as long as two feet in either direction.

More recently in the twenty-first century, [[smartphone]] application developers have created mobile applications that provide the functions of a goniometer. These applications (such as Knee Goniometer and Goniometer Pro) use the accelerometers in phones to calculate joint angles. Recent research supports these applications and their devices as reliable and valid tools with as much accuracy as a universal goniometer.<ref>{{cite journal|last1=Ockendon|first1=Matthew|title=Validation of a novel smartphone accelerometer-based knee goniometer|journal=The Journal of Knee Surgery|volume=25|issue=4|pages=341–345|doi=10.1055/s-0031-1299669|pmid=23150162|year=2012|doi-access=free}}</ref><ref>{{cite journal|last1=Jones|first1=A|title=Concurrent validity and reliability of the simple goniometer iphone app compared with the universal goniometer|journal=Physiotherapy: Theory and Practice|date=2014|volume=30|issue=7|pages=512–516|doi=10.3109/09593985.2014.900835|pmid=24666408|hdl=2328/37026|s2cid=28719817|url=https://dspace.flinders.edu.au/xmlui/bitstream/2328/37026/1/Jones_Concurrent_AM20.pdf|hdl-access=free}}</ref><ref name="KueglerGoni15">{{cite journal |title=Goniometer-apps in hand surgery and their applicability in daily clinical practice |journal=Safety in Health |author1=Kuegler, P. |author2=Wurzer, P. |author3=Tuca, A. |display-authors=etal |volume=1 |pages=11 |year=2015 |doi=10.1186/s40886-015-0003-4|doi-access=free }}</ref>

Modern rehabilitative therapy motion capture systems perform goniometry at the very least measuring active range of motion.<ref>{{Cite web |url= https://www.eumotus.com|title=Markerless Motion Capture. Biomechanical Analysis |website= EuMotus.com|language=en|access-date=2018-01-15}}</ref> While in some cases accuracy may be inferior to a goniometer, measuring angles with a motion capture system is superior at measuring during dynamic, as opposed to static situations. Furthermore, using a traditional goniometer takes valuable time. In the clinical context, performing manual measurements takes valuable time and may not be practical.