Can I skateboard with a chin implant in?

That's tough to answer. A lot of it depends on what type of implant was placed, where is was placed, and how it was secured.  Obviously, implants that are screwed into position are more secure, whereas suture fixation takes time to strengthen.  Generally by 4-6 weeks you are pretty safe. Use caution and be as safe as possible.

 Hi, I have performed many facial shaping procedures, including Chin Augmentation with dermal fillers or silastic chin implants, for over 30 years.  When the chin is weak, this creates an imbalance making the nose appear larger, the mid face top heavy, the lower face looks short, de-emphasizes the lips and allows early formation of a "double chin".  
 Proper placement of a silastic chin implant adds forward projection to the chin thereby creating harmony and balance to the lower face.  Using the same incision, liposuction can be performed to reduce the fat and further shape the neck.  Excess skin, from below the chin, can also be removed through the same incision.  
 I have found that placement of a silastic chin implant, through a small curved incision under the chin (also allows excess skin removal) to be very safe, quick, highly effective and far less invasive than a sliding genioplasty (requires extensive tissue dissection, bone cuts and placement of metal screws and plates to secure the cut segments of bone).  I perform chin implant surgery in 30 minutes or less, often using a local anesthetic alone.   If the chin implant was placed through a small incision under the chin strenuous activity, like skateboarding, should be avoided for 1 month.  If however, an intramural approach was used, the recovery and avoidance of strenuous activity might be 2-3 months.  In any event, you should follow the post op instructions from your chin implant surgeon.Hope this helps.