Slipped my mind about telling you this. Interosseous.
Foot slap gait irregularity may be caused by the long extensors of toes.
Difficulty raising arms above head may be caused by many TrPs including supraspinatus, biceps brachii and subscapularis.
Locked kneecap may be caused by TrPs in the vastus lateralis.
Buckling hip may be caused by a combination of TrPs in the rectus femoris and high vastus intermedius.
Buckling knee may be due to vastus medialis TrPs.Buckling ankle may be due to peroneus TrPs.
Remember, if you already have TrPs and one or more of these symptoms develop, look for the pattern. TrPs can cause or contribute to so many symptoms — not just pain. You need to see a particular kind of physical therapist, one who knows myofascial trigger point massage and subscribes to the ideals set forth in the Clair Davies Trigger Point Therapy Manual.