Flexibility and Grip Strength -- 314.996.3741 Flexibility As we age, muscles tighten and joint range of motion can diminish. This can slow energetic lifestyles and hinder day-to-day activities. A regular stretching program can help lengthen muscles and restore vigor. Grip Strength The grip strength test measures the muscular strength of the upper extremities. There is a strong correlation between grip strength and overall upper body strength. Strength training is an important component of a physical fitness program. It helps muscles become stronger and improve tone, appearance and endurance. This helps increase energy, avoid injury, perform daily activities and improve athletic performance. Cost:  $33 per hour.