Basketball is a fast-paced and aggressive sport. These qualities which make the game so exciting to watch are also what contributes to a high rate of injury such as an anterior cruciate ligament (ACL) tear. What’s more, the ACL injury incident rate for female basketball players is more than three times the rate of male basketball players. How can we lower the risk of an ACL injury? A research team from France explored this question with specific physical training based on jump assessment.
How do ACL injuries occur? For non-contact ACL tears in females, the risk factors are anatomical, hormonal and neuromuscular. From a neuromuscular perspective, erect posture, low muscle activation of the hamstrings or gluteus maximums, and high muscle activation of the rectus femoris are all risk factors. Furthermore “poor dynamic control of the knee” can lead to in high-risk leg positions such as dynamic valgus or “knock-knee” which puts more strain on the ACL.
These neuromuscular considerations interact with other factors such as the mentality of the athlete. Motor Imagery (MI) is a method in which a subject mentally reproduces an action without other outputs. This method has shown to be effective in enhancing motor learning. A combination of these two approaches- mental and neuromuscular- has positive potential.
A study was conducted on female basketball players in which each player was assigned to either the specific physical training group (SPTG), the combined specific physical and mental training group (PMTG), the mental training group (MT) and the control group. The control group continued their basketball practice as normal. For the SPRG and the PMTG groups, information on the ACL was provided as well as suggestions for soft landings on jumps, and correct landing procedure which aims to avoid valgus. Furthermore, these groups incorporated balance, plyometrics, targeted strength training and core work for trunk control. For the MT and PMTG groups, the athletes were instructed to combine internal visual and kinesthetic imagery (“feeling the movement”) of the physical exercises.
To evaluate the different methods of training, the athletes performed a drop jump test before and after the training period. This test involved the athletes dropping on one foot down from a box and immediately jumping on landing. The Peak Vertical Impact force (PVIF) and Rate of Force Development (RFD) were calculated using force plates to measure ground traction forces. An instrumented test such as this can be completed with force plates such as BTS Bioengineering’s INFINI-T plates, or through the portable, wearable, movement analysis system: the G-WALK. For the drop test, the G-WALK’s automatic reports provide the necessary metrics for jump analysis such as the rate of power, height, impact forces and speeds.
Researchers found that jump performance, measured by flight duration increased with the specific physical training and improved results with combined mental and physical training as well. The combined training groups also demonstrated some decrease in the PVIF and RFD – which was suspected to indicate an enhanced capacity to absorb energy in landing for these players.
Researchers concluded that a combined approach with specific physical training and motor imagery has the potential to not only improve performance but reduce risk of injury. The athletes were assessed quantitatively through instrumented test which allowed the healthcare professionals and researchers to objectively compare trainings and measure results.
This post was based on the following article, cited:
Fontenay, B., Lebon, F., Champely, S., Argaud, S., Blache, Y., Collet, C., & Monteil, K. (2013). ACL injury risk factors decrease & jumping performance improvement in female basketball players: a prospective study.