This study included 23 female volleyball players ranging in age from 19 years old to 22 years old. All the athletes were scholarshiped athletes and were sophomores to seniors in their academic career. Each athlete went through a baseline movement assessment (ViPerform AMI) at the conclusion of the season which consisting of 7 core movements. Prior to performing this test, demographic information from each athlete was obtained. This included name, age, weight, previous orthopedic history, previous ACL history and concussion history. The ViPerform AMI movements consisted of:
- 1 minute plank
- 20 squats
- 1 minute sideplank (right then left)
- 10 single leg squats
- 10 single leg hops
- 10 single leg hop plants
- Ankle lunge test
Prior to performing each test, the athlete was fit with 3D wearable sensors (provided by DorsaVi). For the first three tests, the sensors were placed at T10 and L5/S1. For the single limb tests, the sensors were placed on the right and left shin. Each athlete performed each test while data was captured from the sensors.
At the conclusion of testing all athletes, the 3D data and video was reviewed with the team athletic trainer and strength coach. The evaluator then assigned each athlete to level I - level IV of the ACL Play It Safe Program based on a predetermined set of criteria for each level assignment. The ACL Play It Safe Program consists of 2 distinct routines - a pre-practice routine (performed as a warmup) and a post-practice routine (fatigue state training). This was performed in the off season and as a part of their strength and conditioning program and carried through to their in-season competition. The ACL Play It Safe exercises consist of:
- Pre-Practice Routine
- Dynamic Lunge
- Sumo Squat
- High Knee
- Post-Practice Routine
- Single Leg Hop
- Single Leg Toss
- Single Leg Lumbar Hip Disassociation (LHD)
- Glut Med Series
- Side Plank
Each athlete is provided instructions in the exercises, provided the ACL Play It Safe App (consisting of videos of each exercise) as well as the ACL Play It Safe Kit (consisting of TheraBand CLX, TheraBand padded cuffs, stability trainer and drawstring backpack). The pre exercises are performed just prior to training or practice and the post exercises are performed immediately after practice or training. The entire program takes ~20 minutes. The exercises were performed under the direction of the team strength coach and done three times per week. Each athlete performed these exercises throughout the season and compliance was tracked via the strength coaches attendance log.
The team strength coach tracked 100% compliance with the programming as assigned to each athlete.
Hypothesis I - If an athlete performs the ACL Play It Safe program, they will show improved results on the ViPerform AMI test with retesting. The range of improvement on the test ranged from 32-54 point improvement with the average improvement of 41 points. Running a statistical analysis via an independent t-test, clinical significance is noted at P<.05. The independent t-test was P=.001 showing a high correlation with performing the exercises to improvement on the test. Restated, if an athlete performs the exercises they are assigned to based on their individual results on the ViPerform AMI, there is a high probability they will have >12% improvement on the overall battery of tests.
Hypothesis II - If an athlete performs the ACL Play It Safe program based on their individual movement results, this will result in a reduction on injuries and improvement in athletic performance. All recordable injuries were documented through the team's athletic training electronic medical record. For the purposes of this study and with a lack of a control group, this seasons data was compared with the previous 5 years of injury data collected for the volleyball team. When comparing days on the disabled list and recorded non-contact musculoskeletal injuries, there was >70% reduction in total days on the DL and an 80% reduction in non-contact lower kinetic chain injuries.
In addition, there was a average 30# increase in clean and jerk, a 1.18 inch improvement in vertical jump from stance, and .944 increase in vertical jump from approach. The team also recorded their best season performance in 5 years with ability to compete in the Quarterfinals of their division.
It should be acknowledged that we identify and recognize several flaws with this study. One is uncontrolled variables. Without a "true" control group, all we could do is compare results to the previous 5 years of performance and injury data. This introduces a lot of variables that are not controlled. However, aside from this assessment and training, there were no other fundamental changes to the program. There was significant reductions in injury rates, substantial health care cost savings and improvements in performance. Whether there are controlled variables or not, the school and athletic department felt there was a significant return on investment.
Keep an eye out for this paper as it was just accepted to the Journal of Kinesiology in Sport and will be coming out in print in 2020. If you enjoy this blog, please share with your colleagues, athletes and training partners and please be sure to follow us on Instagram @ bjjpt_acl_guy and twitter @acl_prevention so we can continue to share some of the latest news. If you happen to be at APTA Combined Sections this year, please come by and see us Thursday where we will be presenting on RTSport Following ACLR. Train hard and stay well.