Seven percent of athletes who score less than 20% body weight will tear their ACLs each season.1
Recent research confirms that when piriformis strength is less than 20% body weight, the individual is significantly more likely to be injured. ACL tears are especially common when a weak piriformis is present.
The ToePro/Hip Strength Dynamometer makes it easy to measure hip strength. An ankle strap attachment allows you to create a ratio between hip strength and body weight. Simply multiply the patients weight in kg by .2 to work out what minimum strength is and perform the test e.g. 80kg x .2 = 16kg.
Read the full article by Dr Thomas Michaud on hip strength and knee function here.