Your physical therapist is an expert in human movement, and can help you safely reach your fitness goals. People think of PTs as the person to see after an injury, but a visit before you change your activity level could prevent injury in the first place. An evaluation by your PT will include assessment of your strength, range of motion, and functional movement patterns - think jumping, running, squatting, carrying. Some PTs even like to use a standardized assessment, such as the Functional Movement Screen.
Most common injuries from new fitness routines are caused by underlying weakness, range of motion deficits, or compensatory movement patterns. Your PT will find these during your assessment. They can then prescribe exercises or movements to address the issues found and get you safely moving into the new year!
The other common way people get injured working towards their resolution is with overtraining, or doing too much too soon. Physical therapists are also experts in exercise prescription and program design. Your PT can help you create a routine specific to your needs and goals that will progress appropriately and keep you out of trouble.
So stop only thinking of your PT after you're injured. In this case, it's true that an ounce of prevention is worth a pound of cure. Seeing your physical therapist before you start on your resolution can keep you on track, injury free, and help you reach your goals for the new year!