The International Association for Cannabinoid Medicines (IACM) mission is to advance knowledge on cannabis, cannabinoids, the endocannabinoid system, and related topics especially with regard to their therapeutic potential. As such the IACM has an excellent search tool for over 400 various cannabis related clinical studies and reports. Below is an example of such a search for quantitative study on multiple sclerosis.
One of the studies found has a focus on the stretch reflex in MS spasticity.
With a link to PUBMED full text. (Membership is required to read the full test beyond the abstract listed below)
The above study with the title "The effect of cannabinoids on the stretch reflex in multiple sclerosis spasticity" can be found in International Clinical Psychopharmacology article 2016 Jul;31(4):232-9..
The International Association for Cannabinoid Medicine search tool is located at http://www.cannabis-med.org/studies/study.php. An older list of various studies before 2012 can be found at http://www.cannabis-med.org/english/studies.htm