What We Know About ACL Injuries

Summarizing previously published articles in the wake of Juju Watkins' injury.

Juju Watkins’ injury last week, and the discussion of ACL injuries in women’s sports, prompted me to search through old articles to compile some information based on research and experience. Multiple articles are combined below with minimal editing beyond reducing repetitiveness.

A tweet announced the recent anterior cruciate ligament (ACL) tear of a promising high-school sophomore. The tone on a local girls’ basketball message board was blasé. Everyone in girls’ and women’s basketball is accustomed to ACL tears, and nobody was too disheartened. There was a sense the player would miss one season and return like new, and she was talented enough that her college recruitment would not be affected.

Everything about the sentiment was correct, and a travesty at the same time. Yes, ACL tears are common. Yes, surgery to repair torn ACLs is amazingly good, and players can return to play at or near the same performance level. Yes, talented players will be recruited despite injuries. The travesty is accepting these facts. Why do we accept more than 7000 high-school girls’ basketball players rupturing their ACLS annually (Ford et al., 2003)? Why do administrators, coaches, and parents not do more to keep players safe?

This player may return and earn her scholarship, but girls have a higher incidence of ACL injuries to the contralateral knee compared to males (Shelbourne et al., 2009). The injury incidence to either knee after reconstruction is associated with younger ages and higher activity levels (Shelbourne et al., 2009), such as high-school basketball players. Joint kinematics remained altered 12 months post-surgery (Oberlander et al,, 2014), potentially explaining subsequent injuries.

Those motivated for sports participation by “achievement”, such as aspiring college athletes, experienced more pain and worse function two years after injury than those with other motives (Roessler et al., 2014), and had an elevated risk of knee osteoarthritis (Lohmander et al., 2004; Oberlander et al., 2014; Roos, 2005). Therefore, even if players successfully return from injury, play, and earn a scholarship, they are at-risk for subsequent ACL injuries, likely to experience pain two years post-injury, and looking at knee osteoarthritis by age 30. Should we ignore these outcomes simply because players return at an acceptable performance level?

There are three potential mechanisms underlying ACL injuries: Anatomical, hormonal, and bio-mechanical (Ford et. al, 2003). Anatomical and hormonal issues are beyond a coach’s control, but training can affect bio-mechanical issues. Three bio-mechanical or neuromuscular issues involved in the ACL injury mechanism are: (1) Ligament dominance; (2) quadriceps dominance; and (3) leg dominance (Ford et. al, 2003).

Ligament dominance refers to the inability of the lower-body limb musculature to absorb the forces during a sports maneuver resulting in excessive loading of the knee ligaments (Ford et. al, 2003).

Quadriceps dominance has been mentioned frequently; females tend to show a preference for quadriceps recruitment rather than hamstrings recruitment to provide dynamic knee stability during jumping and landing (Ford et. al, 2003). Hamstring fatigue may be a factor, as it increased ACL loading in a sidestep cutting task (Weinhandl et al., 2014).

Leg dominance is when athletes favor one leg over the other, potentially leading to injuries because the non-dominant leg is not strong enough or the dominant leg is overworked.

Ford and colleagues (2003) found greater valgus angles during the stance phase of a depth jump for females compared to males and the female’s dominant leg compared to the non-dominant leg (dominant leg was defined as the leg used to kick a ball). “This likely reflects changes in contraction patterns of the adductors and abductors of the knee, primarily the knee flexors, the hamstrings and the gastrocnemius… Decreased neuromuscular control of the knee joint reduces knee-joint stiffness and increases risk to the ligament” (Ford et al., 2003).

Other studies have shown a correlation between ankle injuries and ACL injuries (Kramer et al., 2007), and I see athletes favor previous ankle injuries over a year after returning to action. Previous ankle injuries may affect the strength and muscle recruitment patterns of the injured limb leading to weakness in the injured limb and altered recruitment patterns on the non-injured limb. Previous ankle injury could reduce the range of motion around the ankle joint and limit the flexion and force absorption at the base, sending the force higher up the kinetic chain to the knee or hip.

Non-contact ACL injuries usually involve a deceleration before a change of direction or landing with the knee between 20-degrees and full extension (Boden et. al, 2000). Rebounding was cited as the most-frequent cause of injuries to women’s basketball players (Powell et. al, 2000). Three reasons are: (1) Lack of balance caused from jumping and landing in a crowd; (2) head and eyes directed toward the basket leading to a more erect posture at landing; and (3) the desire to jump again quickly.

Athletes who had suffered ACL injuries processed information from the injured knee differently (Grooms et al., 2015). Those who had suffered ACL injuries relied more on their visual systems than movement (proprioception) or spatial awareness (Grooms et al., 2015). The injury mechanism disrupted the use of proprioception and spatial awareness to provide the feedforward mechanism of anticipation for landings, and this change in the processing of information may explain subsequent ACL injuries (Grooms et al., 2015).

PREVENTION

During my first season coaching in Europe, I observed professional women’s basketball teams using their pregame warmups to perform a series of movements without the ball. Some teams used the ball for less than half of their warmup. I scoffed at these teams, attempting to maximize the number of pregame shots for my team. When I returned home after the season, and coached four players from the same high-school team who had torn their ACLs in the same season, I reflected on the professional league and realized no player had torn her ACL during the entire season, and no player appeared to have returned to play from a recent serious knee injury. I investigated these exercises and learned about dynamic warmups.

I now start practices with a focus on movement, specifically to reduce ankle and knee injuries. Nearly every study of the FIFA 11+ program (a 10-minute program) has found the greatest factor in its efficacy is compliance: Those who perform the program more consistently fare better than those who perform the program less consistently or who do nothing at all (Steffen et al., 2013).

I use a short dynamic warmup, which is similar to well-researched neuromuscular training programs that include a combination of plyometrics, strengthening, stretching, and balance training (Sugimoto et al., 2012). These neuromuscular training programs have been found to decrease knee injuries by 62% in women’s sports (Hewett et. al, 1999) and reduce the incidence of non-contact ACL injuries (Hewett et al., 2007; Kiani et al., 2010; Mykleburst et al., 2003; Steffen et al., 2008).

Ten minutes is not a large training stimulus, but the players engage in thousands of repetitions over a season. I emphasize foot contacts, whether the exercise is a skip, hop, jump, or sprint, with players dorsiflexing their ankles, positioning their feet to drive into the ground on the next ground contact. Often, players point their feet at the ground and are not set up for the next ground contact or land on their heels.

Plyometrics has been considered an esoteric training model, yet light and moderate plyometrics activities are basic fundamental movement skills such as running, jumping, skipping, and hopping. Young athletes should learn and train fundamental movement skills before investing in sport-specific training programs. Athletes who develop these skills at young ages will use them more as they grow. This added experience will refine their techniques and increase their strength as they mature. Addressing these issues in high school or college is a necessity now, but should not be. We should invest time and resources into young (four to seven-year-olds) potential athletes to provide the best developmental foundation.

Teams often do not concentrate on the movement quality or receive instruction and feedback during warmups; coaches set up cones for the next drill rather than observe the movements. Efficiency over efficacy. The exercises are not magic; the benefits are reduced or negated when done poorly or infrequently. Quality movements repeated daily throughout a season improve performance and reduce injuries.

Evaluation

A bare minimum for high-school players is a full range of motion bodyweight squat with feet pointed straight ahead and feet under the hips. Players who cannot do this have a problem. The problem may be a lack of strength, a lack of ankle mobility, a lack of hip mobility, a lingering injury, or something else entirely. The coach may need to refer players to a physical therapist or strength coach, or the coach may have the knowledge and experience to add corrective or progressive exercises. Regardless, playing without correcting this issue sets up the player for future, chronic problems.

Squat strength was shown to be the best predictor of knee valgus during bilateral and unilateral drop jumps (McCurdy et al., 2014), and knee valgus has been identified as a risk factor in non-contact ACL injuries (Hewett et al., 2005). A unilateral squat compared to a bilateral squat increased EMG activity in the gluteus medius and hamstrings (McCurdy et al., 2010), suggesting single-leg squats may be an ideal exercise to incorporate into a strength training and injury reduction program.

A subjective assessment to determine poor knee control is as effective as a two-dimensional (2D) test of frontal plane knee motion (Stensrud et al., 2011), and 2D tests have a high correlation with 3D motional analysis, which is considered the gold standard (McLean et al., 2005). Therefore, a subjective assessment can be used to evaluate knee control.

The single-leg squat (SLS) and bilateral vertical drop jump (VDJ) using a 30 cm box were scored 0 to 2: “The score 0 indicated (A) no significant lateral tilt of the pelvis, (B) no obvious valgus motion of the knee, and (C) no medial/lateral side-to-side movements of the knee during the performance. Players rated as 1 displayed (A) some lateral tilt of the pelvis, and/or (B) the knee moving slightly into a valgus position, and/or (C) some medial/lateral side-to-side movements of the knee during the performance. Players rated as 2 displayed (A) lateral tilt of the pelvis, and/or (B) the knee moving clearly into a valgus position, and/or (C) clear medial/lateral side-to-side movements of the knee” (Stensrud et al., 2011).

This video of a VDJ demonstrates a clear valgus position at landing, and should score a 2 and be classified “at-risk” in my non-medical analysis. She needs to improve her jumping and landing techniques, develop more lower-body strength, or both. A coach can identify her as “at-risk,” and direct her to a knowledgeable strength coach or physical therapist if lacking the knowledge to devise a program to correct the issues.

Watch for the same limitations on the SLS. The first red flag is putting down her other foot, which demonstrates a lack of balance and/or a lack of strength. Perform a single-leg balance test to rule out balance: Stand on one leg with the other leg raised and hold the position without wobbling; balance is an issue if players cannot get to 20 seconds. After ruling out balance, address a strength deficiency. Monitor the knee control as the player descends into her single-leg squat. Her knee should track over her foot. I have seen athletes with their hip pointing the opposite direction of their knee! The athlete lacks the strength to control the movement when the knee moves inward into a valgus position and is designated “at-risk.”

The SLS and VDJ identified different participants with poor knee control. Athletes failed different tests; using both tests is best to capture all at-risk athletes. The tests should suggest the major limitation: The SLS is primarily strength and balance, where the VDJ could be technique, strength, or elastic strength.

Traditional injury prevention programs teach a proper landing position, a half to three-quarter squat. Of course, defenders, angles, shot attempts, the ball, etc. prevent these perfect landings. Suboptimal positions happen because of the game’s unpredictability. Many injuries occur in an extended position with eyes directed overhead at the basket or the ball. Most prevention programs ignore these positions.

Athletes in most jump training programs look at the ground as they land. They rely on their visual systems to anticipate the ground, whereas many landings during games occur with the eyes focused on the basket or ball. Players must develop other mechanisms for anticipating the ground. How do players develop these other mechanisms when they train with full vision? Additionally, postures change when looking at the ground, a hurdle, or a box compared to the more erect landing when shooting or rebounding. Looking at the ground may facilitate a more perfect landing technique, but is the perfect technique useful in reducing injuries in games when suboptimal positions are required for performance?

Initially, beginners learn the ideal landing technique. Once learned, perturb the system. Players who learn to handle different positions in controlled environments will be equipped better to handle game demands. Using cones, hurdles, and boxes are good tools, but some training must use other methods to develop the proprioceptive sense in jump landings. Occlusion goggles represent one method, but basic tip drills off the backboard have the same effect: The eyes focus on the ball, as during games, and the system must anticipate the landing without vision. Moving to a medicine ball or a ball filled with water increases the difficulty of tracking and catching and improves learning. Adding minimal contact on the landings perturbs the system to challenge players, and adds specificity to prepare players for games, as most rebounds and layups are contested with some amount of contact in the air or on the landing.

Most weight-room workouts focus on full-range movements (when athletes have the capacity): Full squats or high step-ups. These exercises utilize the greatest number of muscle fibers and produce greater work. We use these exercises, but also incorporate a low step-up with an overhead barbell because many injuries occur with eyes overhead and the body in an extended position. We dangle weights with a band to challenge balance and their core. This is a low-weight exercise. The challenge is posture, balance, and stability through movement, not intensity.

I have no proof of their effectiveness, but our two uncommon weight-room exercises are this low overhead step up (and especially the emphasis of stepping down to the box and holding balance at the end) and the Farmer’s Walk, which we do religiously. In Easy Strength, Dan John wrote, “The loaded carry does more to expand athletic qualities than any other single thing I've attempted in my career as a coach and athlete.”

The similarity is the upright (extended) position and a small range of motion similar to landing or cutting in games. We develop general strength and mobility through other, common exercises, but these improve the specificity and transferability to the court because players do not land from layups or rebounds in three-quarter to full squats. Players play in an upright to quarter-squat position, and injuries occur in these positions. Therefore, we train and challenge players in these positions.

Lack of hamstring strength has been identified as a risk factor in non-contact ACL injuries (Myer et al., 2009), but hamstring-specific exercises may not be best for injury reduction. Many isolated hamstring exercises, such as a hamstring curl, do not train inter-muscular coordination or the speed of performance required in games (Gambetta & Benton, 2008).

I use a single-leg straight-leg deadlift with dumbbells as my primary hamstring-specific exercise, as it also improves single-leg balance. I also do a lunge-and-reach series with lunges and reaches into different planes.

Lunge series: The lunge series starts with the lunge matrix (sagittal, frontal, transverse). I use dumbbells and reach with the contralateral hand. As I return to my beginning stance, rather than press with the same hand that reached, I press with the other hand. In a forward lunge, I step forward with my right foot and reach with my left hand toward my foot. As I return to my starting position (athletic stance), I press overhead with my right hand.

In addition to developing better strength, sprinting, back-pedaling, and plyometrics enhance hamstring strength and coordination, as well as train players to resist fatigue. Years ago, Mackie Shilstone, previously Serena Williams’ fitness coach, told me the relative lack of hamstring injuries in basketball players (hamstring strains accounted for 3.3% of NBA injuries over 17 years, Drakos et al., 2010) and football defensive backs was due to the volume of lateral and backward running. I use some basketball drills, such as chaser layups and a two-player warmup, to include greater lateral, curved, and backward running; the potential basketball improvement is good, but is primarily a motivation to increase the intensity and focus on the activity for an injury prevention stimulus.

Teaching Jump Stops

Years ago, many coaches stopped teaching jump stops because someone on ESPN said during the NCAA Tournament that girls were not supposed to jump stop. The problem is not jump stops, but an inability to decelerate correctly. Players must stop forward motion, change directions, and land from jumps on rebounds or after shooting. We must train these general skills, not eliminate sport-specific skills and cross our fingers for health.

A recent study examined jump stops using 14 female college and high school girls basketball players with at least two years of experience and no prior knee issues (Myers & Hawkins, 2010). The players executed multiple jump stops without instruction. After a series of repetitions, the researchers instructed the players to use a specific technique to measure their intervention: “The intervention targeted: Increasing the amplitude of the jump prior to landing, increasing the amount of knee flexion at landing, and striking the ground with the toes first,” (Myers & Hawkins, 2010). The giant red flag from the study, considering most participants were NCAA Division 1 players, was:

“Jump stops were performed with the toes striking the ground first during the intervention condition versus the majority of jump stops performed with the heels striking the ground first in the baseline condition” (Myers & Hawkins, 2010).

These college players needed university researchers to perturb their jump-stop techniques to avoid landing on their heels. What coach teaches players to land on their heels? How do players develop throughout high school and college with a heel-strike landing? Coaches need to attend to movements more closely to reduce injuries rather than focusing solely on performance (Did she make the shot?) and legality (Was it a travel?).

I have seen two methods for teaching landing mechanics:

1. Land like a Ninja: Land softly; initiate the landing on the balls of your feet and sit back to a flat foot as your knee-bend increases. Sit down by dropping your hips.

2. Dorsiflexion: Dorsiflex your ankle (toes up) and land on the balls of your feet. In this landing, there is less knee flexion. This landing takes advantage of the stretch-shortening cycle for repeat jumps. Even when landing with a dorsiflexed foot, the heel should not hit the ground first.

The study suggested the vertical component does not influence the incidence rate of injuries (higher jumps do not increase injury frequency), and, in fact, a greater amplitude may decrease injuries (possibly by creating a more straight-down landing, which may help to control the sheer force on the ACL caused by controlling the anterior movement of the tibia). The study also found players jumped higher when using the intervention technique. The improved technique potentially leads to fewer injuries, and improves performance! It is a win-win, yet one ignored by many coaches and trainers. This is not a matter of adding resistance training sessions or incorporating plyometrics. The intervention suggested a more effective jump stop — a basic fundamental — would decrease risk of an ACL tear. It is not adding anything, but improving the instruction to create a more effective jump stop.

Coaches can start with the closed skill. Emphasize the higher amplitude on the jump, the toe-to-heel landing, and deeper knee flexion. Next, move to more involved skills. Execute the jump stop with a ball. Then, jump stop while dribbling; then on the catch; then, land with the ball from a rebound. Finally, move toward the open-skill application by having players jump stop as a reaction to a verbal or visual stimulus (Red Light-Green Light works well for youth players).

Learning from Tennis

I contacted several experts on sports medicine and ACL injuries to investigate the disparity between ACL injuries in tennis and basketball players, as the sports include similar movements, although there are several differences:

1. Basketball is a more vertical game, and basketball players land from jumps with more force, which is the site for many ACL injuries.

2. Basketball players often suffer ankle injuries, and studies have shown a correlation between previous ankle sprains and ACL injuries.

3. Basketball includes many different feet for players to land on or avoid, which may increase ACL injuries.

4. Basketball players spend more time with a higher sight line, and ACL injury frequency may increase when players are looking up.

Two other explanations beyond the competitive differences were offered:

1. ACL injuries have more to do with a strength deficit than anything else.

2. Tennis players train differently than basketball players, and this difference may decrease ACL injuries in tennis players because (a) tennis requires a more developed core and (2) is predicated on changing directions and training focuses more specifically on this area.

A recent study by Dr. Timothy Hewett suggested core strength — and specifically the ability to control the core and upper body in quick movements (landing, changing directions) — reduces injury risk. Dr. Hewett wrote players must prevent their upper bodies from swaying as they change directions. Hitting a tennis ball prevents this upper body swaying. Basketball players may not develop this skill. They may lack the strength or movement skills to prevent the upper-body swaying when reacting quickly.

Tennis players spend more time training change of direction movements from a young age — especially reactive change of direction movements — leading to better footwork, more efficient movement, and fewer injuries. A tennis player’s success depends largely on her ability to get to more balls, which means starting and stopping quicker. The best players cover an amazing distance and manage to get to the ball to hit while on balance. This skill requires many things — anticipation, quickness, footwork, balance, strength — including the ability to control one’s movement.

In addition to increasing injury risk, upper-body swaying worsens change of direction performance. Imagine defending a dribbler. You must react quickly and change directions when he crosses over to go to your left. Your change of direction is slowed when your upper body continues moving to the right (outside your base of support). Instead, you must get your foot outside your knee and your knee outside your hip to “meet your momentum”, as Lee Taft teaches, and prevent the upper-body swaying.

Many coaches teach a vertical alignment of the foot, knee, hip, and shoulder (a straight line, perpendicular to the floor). This is possible when demonstrated at slow speeds. How can players control their momentum at faster speeds? On the subway, with nothing to hold, do you stand up straight? Do you lean in the direction of the movement as the train stops? No; you use a wider base and lean into the stop, away from the direction of the movement. The same applies. You cannot apply sufficient force when you attempt to stop in a vertical line — players take an extra step or two to meet their momentum or hurt their knee or ankle as the force goes somewhere. Skill performance increases and injury risk decreases when change of direction technique improves.

Eliminating ACL injuries is impossible, but incorporating better technique instruction into normal footwork and jump stop drills as well as training landing techniques during dynamic warmup drills may reduce injuries and improve performance, which ultimately leads to a better team performance and more wins.

REHABILITATION

Basketball coaches defer to physical therapists and athletic trainers to re-introduce players to physical activity. The medical professional clears the player, and the coach follows the constraints or limitations the PT or ATC advises. The return to play process occurs in stages, as players move from pre-planned drills to reactive, but non-contact drills, to live drills, and finally to scrimmages. Often, there is no additional hurdle to clear; the player progresses once she completes one level with no further injury or pain. There may or may not be additional rehabilitation exercises or strength training once this process begins.

Previously I worked with late-stage rehabilitation and return to play. They were cleared by their physical therapist or doctor despite an obvious lack of preparation for full on-court activities. This occurred, at least partially, because their insurance ran out, and the doctor or physical therapist helped the family by not requiring additional, uncovered visits. They had no limitations in daily life and completed basic physical therapy, but basketball demands are greater.

Rehab never ends. Training is rehab, and rehab is training, as Charlie Weingroff said. Athletes are not fixed when cleared by their doctors. Basic rehabilitation is inadequate. “An ACL injury is a brain injury,” as physical therapist Bill Knowles said. The body adapts to the injury and learns a new way to move. Players must re-learn their basic movements when returning to play. Grooms and colleagues (2015) used eye occlusion glasses to help patients develop better proprioceptive sense and spatial awareness, and re-train their brains.

I signed a player one summer without knowing much about her. She was a transfer within our conference, described by a friend as a great person and teammate, and I imagined she would never play. She expressed a desire to play her final season and then move into a medical technician field. She was supposed to be our 12th player, so I did not investigate further.

She loved to play and work out, and we began working in the summer when most players were gone. She started with a dynamic warmup and struggled in one direction on repeat hops, which prompted me to ask about previous injuries. Naturally, she tore her ACL during her senior year of high school. She demonstrated a clear asymmetry between her limbs and obvious strength and coordination deficits after playing a full season of college basketball. She moved more like someone two to three months post-surgery, not two years.

Most rehab programs restore patients to daily living, not to basketball performance. There is a gap between the rehab and the sport, and many teenage athletes are forced to bridge this gap on their own or with an inexperienced strength and conditioning coach. When we started with some simple exercises, she said she had never used similar exercises during her rehab.

Her rehab had consisted primarily of leg extensions and leg curls. Leg extensions and leg curls do not prepare athletes to return to the court. Most physical therapy occurs in a controlled setting and primarily in the sagittal plane; that is, straight lines. Basketball is multi-planar. An athlete may be cleared because she demonstrates symmetrical strength in a leg extension or hamstring curl, but dynamic movements differ. Can she express this strength rapidly in an athletic movement? Slow or delayed force development rather than a lack of absolute strength may be a greater risk factor.

She performed single leg medicine ball (MB) reaches: Starting on one leg with a MB overhead as high as possible, she bent and reached forward touching the ground as far in front of her as possible before returning to the starting position. Next, we worked on her squat, as she could not get into a full squat position, even with assistance. She did assisted squats for time and MB squats. Next, she did three variations of step-ups followed by loaded carries. Finally, I showed her an eccentric leg press to do on her own.

Beyond strength, she needed to improve her coordination and proprioception. Single-leg and medicine ball exercises are a start. These movements became more dynamic and reactive, and eventually progressed to plyometrics, as her initial rehab included no jumping. We emphasized balance and coordination to improve landings, cuts, and other actions. She performed these controlled movements with some variability before we moved to uncontrolled movements. We practiced uncontrolled and reactive movements before moving to contact and live play.

Most players return to the court after an ACL injury because of the advances in surgery, rehab, and strength training, but many have lingering problems, despite positive outward appearances — scoring points, shooting percentages, scholarship offers. Many miss late-stage or end-stage rehab/training before returning to play, and they are ill-equipped for the game demands. They return to play because they are cleared, and do not continue their rehab because they believe they are fixed or they never recovered fully in terms of the game’s physical demands. Either way, they risk subsequent injuries, not to mention diminished performance. She managed to change her body and prepare to perform in college basketball, rather than just survive the season, and she developed into our eighth player and transferred to a four-year program to play her final two seasons and complete her Bachelor’s degree.

I signed a second player recovering from ACL surgery in the same summer. She had her ACL surgery in February, and had jumped, hopped, leaped, and more during her initial rehab before arriving in the summer. Her doctor cleared her to return to the court before she arrived.

Her strength, range of motion, and movements were good when she arrived. She excelled in stationary, sagittal-plane exercises, and was stronger than many of her healthy teammates. In her first workout, she joined another player on a set of box jump to depth jumps. She clearly favored her injured leg on her first depth jump (stepped off a 12-inch box, landed, and jumped as high as possible). I estimated that she had 70% of her weight on her non-injured leg, but she did not feel anything. That was her last repetition.

She jumped for distance off one-leg and landed on two feet. She looked strong on her right (uninjured) leg, and acceptable on her left leg, but there was a clear difference visually and in distance (without having to measure). Next, she hopped for distance; right leg to right leg, and left leg to left leg for one hop. She landed gingerly on her left leg. We returned to two-foot landings. A player who cannot hop for distance and land solidly on one leg is not ready to play basketball. If we were in season, I would not have allowed her to practice, despite being cleared by her doctor.

We automatically picture ACL injuries when we hear about knee injuries, but there are other injuries. One player suffered a meniscus injury. I assessed his knee extension to put together his rehabilitation program. One should be able to sit on the ground with legs extended and flat on the ground and flex his quadriceps to lift his heel off the ground. He could not. I tested other players who presented with knee pain, and most could not raise their heels. They could not access terminal knee extension, which may have contributed to their knee pain.

Every player with knee pain, whether chronic or acute, lacked terminal knee extension. Two players had no muscle tone in their vastus medialis (the inside of the leg above the knee) when they flexed their quadriceps. One had the symptoms of patellofemoral pain syndrome, and the other had patellar tendonitis or jumper’s knee. They had issues beyond their VMO (the girl had knee valgus in a single-leg squat, which likely meant knee valgus when running, and the boy had poor ankle dorsiflexion), but the lack of strength and inhibition of the VMO was a deficiency we worked to remedy.

Our first exercise was placing a ball under his knee and pushing his knee to the ground. We used a yoga ball rather than a foam roll to facilitate this feeling of pushing the cushioned ball into the ground rather than extending his foot into the air. The second exercise was a banded standing knee extension.

The goal of strength and conditioning is more than training muscles – movement is directed by the mind. Athletes must develop the proper motor patterns. Increased force production with poor motor pattern efficiency leads to less than optimal results and injury when the load exceeds the capacity. Injuries, whether acute (ACL tear) or chronic (patellar tendonitis), occur when players develop the muscles for a 40-inch vertical jump without the motor pattern (skill) to reduce force effectively and efficiently upon landing.

Train 4 The Game in Austin, Texas train transverse jumps and hops and unorthodox hops. They train through positions players face in games that often are not incorporated in training. We used some of these exercises in our dynamic warmups last season. Increasing the number of movements in which athletes can move safely reduces injury risk. Artificially limiting movements and hoping they do not occur is not a prevention program any more than is prayer.

Rehabilitation tends to be incomplete when completed outside of a sports setting because physical therapists focus on returning patients to health and tasks of daily living, not the activities and intensity of the game. Rehabilitation may be incomplete regardless of one’s on-court performance. Players may perform like they are recovered fully, but their bodies may be compensating, which may contribute to a subsequent injury. Legendary track and field coach Kelvin Giles (2014) wrote in This is Not a Textbook, “World-record holders don’t show us ‘perfection’ in technique. They simply show us how their bodies have adapted to the challenges.” Athletes are geniuses in movement and adaptations, but we also must ensure their genius does not predispose them to subsequent injuries due to inadequate rehab or training. Rehab never ends.