Goniometry Question

Hey guys!
i have a question re goniometry i was asked in an exam that i was'nt able to answer,and Id really like to know the answer. So with active and passive goniometry..when done passively by physio the patient reached says 120 degrees hip flexion but actively reaches only 112 degrees..why is this so? what is stopping patient reaching full range themselves? What does it say about patients condition?

Thanks :)

Just a quick addition to physiobobs reply as below, as he says musculoskeletal issues so in addtion to the muscle just beign weak, it may be actually be weak as it is injured.
Also a ligament may be injured, MCL in knee for instance patient cannot actively go thru pain but passivley full range can be achieved. Glenohumeral jnt, active bursitis, pt cannot raise above 90 degree but may be able to go fully passively.
I could also argue that a joint can still be to blame, in that it may not be gliding correctly so actively blocks whereas passivley csan go further - manipulation can help here.
Hope that adds to the list and also that unfortunately physio isn't just basic 101 it takes years of clinical expereince to make decisions and still get them wrong occasionally!
Re: Question- Goniometry

If passive range is greater than active range it would suggest that there is no physical barrier to movement from the joint itself. Thus a reduction in active range would perhaps be due to muscular weakness. That could be due to disuse, attrophy, nerve conduction problems etc. It's really Physio 101 in terms of the basic assessment to help dissociate between joint vs musculoskeletal issues. Then based on that information you would begin to look at manual muscle testing to see if in fact the muscle associated with that joint range of movement is testing on the weak side.

Hope that helps your understanding.

thanks for the help guys!

Difference in active and passive is not always related with musculoskeltal problem because it is present in normal fit human being also.Normally passive range is more than active range because each joint has a small amount of motion available that is not under the voluntary control. The additional passive range that is available at the end of normal active range is due to stretch of tissues surrounding the joint & reduced bulk of relaxed muscles.
This additional passive range helps to protect the joint structures because it allows the joint to absorb extrintic forces.

I hope you find this information useful and I want more information about passive range of motion, please let me know.