I am in week 4 of my half Marathon Training Plan for the Great North Run .... my first half marathon. Last night I went to netball and injured my knee .... on a jump I felt a pop to the lateral knee and collapsed. Ice pack was applied almost immediately and started ibuprofen. Today the knee is a bit swollen ( laterally and posteriorly) and not fully extending or flexing. Looked at a 3-D anatomy site and think I may have "popped" the popliteus muscle? .... any advice please. Am so upset about the effect on my training that this might have. Any advice please?