The intersection of high-performance athletics and orthopedic medicine has long been a focal point for safety innovation in professional sports. However, for Dr. Greg Lichtman, a practicing orthopedic surgeon based in Auburn, California, the focus has shifted from the operating table back to the mountain. While Lichtman’s career is defined by his ability to reconstruct the anterior cruciate ligament (ACL) for athletes, his primary objective is to decrease the frequency with which skiers require his surgical intervention. Through his dual roles as a private practitioner near the Tahoe basin and a pool physician for the U.S. Women’s Ski Team, Lichtman is championing a data-driven approach to injury prevention that aims to bridge the gap between recreational skiing safety and the rigorous standards of professional land-based sports.
A Career Shaped by the Slopes and the Lab
Dr. Lichtman’s trajectory into the field of sports medicine was heavily influenced by a formative year spent at the Steadman Philippon Research Institute (SPRI) in Vail, Colorado. SPRI is globally recognized as a premier destination for orthopedic research, particularly concerning the knee and hip. During this gap year, Lichtman moved beyond the typical roles of a seasonal worker to immerse himself in the clinical realities of high-level alpine injuries. Working alongside U.S. Ski Team athletes, he witnessed firsthand the physical and psychological toll of ACL tears, a common yet often devastating injury in the sport.
Following his time in Vail, Lichtman’s professional path led him to a sports medicine fellowship at the University of Massachusetts. It was here, while skiing the notoriously icy terrain of the East Coast, that he began to notice a significant disparity in injury prevention resources. While sports like soccer and basketball benefited from well-documented, validated ACL prevention programs—resulting in injury reductions of 40 to 60 percent—skiing appeared to lag behind. This observation sparked a career-long inquiry into the specific biomechanical mechanisms that lead to ligament failure on the snow.
The Biomechanics of the ACL Tear
The ACL is one of the four major ligaments that stabilize the knee joint, specifically preventing the tibia (shin bone) from sliding in front of the femur (thigh bone). In the context of skiing, the ACL is subjected to extreme forces, often during moments of lost control or high-speed maneuvers. According to Dr. Lichtman, the majority of these injuries occur within a remarkably narrow 60-millisecond window—a timeframe so brief that human reaction time is often insufficient to prevent the damage once the mechanism has begun.
Lichtman identifies two primary mechanisms responsible for the majority of non-contact ACL tears in skiing: the "Slip-catch" and the "Phantom Foot."
The Slip-catch mechanism is frequently seen among competitive racers and advanced skiers. It occurs when the downhill ski loses contact with the snow, causing the leg to straighten momentarily. When the ski abruptly re-engages with the snow, the knee is forced into a deeply flexed position while the lower leg undergoes rapid internal rotation. This combination of compression and rotation is the catalyst for the ligament’s failure.
Conversely, the Phantom Foot mechanism is a common cause of injury for recreational skiers. This occurs when a skier falls into the "backseat"—a position where their weight is centered over the tails of the skis rather than the front of the boots. In an attempt to recover or "save" the fall, the skier may inadvertently unweight the uphill ski, placing all their weight on the inside edge of the downhill ski. The tail of the ski then acts as a lever, or a "phantom foot," twisting the knee in a way that the binding cannot always compensate for before the ACL tears.
Statistical Context and Environmental Risk Factors
Data regarding alpine skiing injuries suggests that while the overall rate of injuries has decreased over the last several decades due to better equipment, the incidence of ACL tears has remained stubbornly high. Medical records indicate that ACL injuries account for approximately 15 to 20 percent of all skiing-related injuries. Dr. Lichtman notes that environmental factors play a significant role in these statistics.
Flat light conditions are particularly hazardous. When a skier’s depth perception is compromised, they are less likely to anticipate changes in terrain, such as bumps or ruts, which can kick them into the backseat. Furthermore, snow consistency varies by region, presenting unique challenges. In the Northeast, hardpack and "bulletproof" ice increase the likelihood of the Slip-catch mechanism. In the Sierra Nevada mountains, the heavy, wet snow often referred to as "Sierra Cement" can catch a ski and rotate the leg with immense force, leading to torque-related injuries.
Chronologically, the month of December often sees a spike in ACL injuries. Dr. Lichtman attributes this to a combination of early-season excitement and a lack of physical conditioning. As the day progresses and muscles fatigue, a skier’s ability to maintain an "athletic stance"—knees slightly bent, weight forward, and shins pressed against the tongues of the boots—diminishes. Once a skier enters the backseat due to exhaustion, they become highly vulnerable to the Phantom Foot mechanism.
The Preventative Strategy: Beyond the Wall Sit
To combat these risks, Dr. Lichtman advocates for a shift in how skiers approach pre-season conditioning. Traditionally, skiers have relied on quadriceps-heavy exercises like wall sits to prepare for the slopes. While quad strength is necessary, Lichtman argues that it is insufficient for true injury prevention.
"High-level athletes often neglect the muscle groups that provide lateral stability," Lichtman explains. He emphasizes the importance of the gluteus medius and the core. The gluteus medius is responsible for hip abduction and stabilization; when it is strong, it helps keep the knee aligned directly over the toes, preventing the "valgus" (knock-kneed) position that is a precursor to ACL failure. Additionally, a strong core—specifically the obliques—allows a skier to recover their balance more effectively when they are thrown off-center, reducing the time spent in the dangerous backseat position.
Equipment and the Role of Bindings
A common misconception among recreational skiers is that a properly functioning binding will always prevent an ACL injury. However, as Dr. Lichtman points out, many ACL tears occur before the binding ever releases. The forces required to tear the ligament are often lower than the forces required to trigger a standard heel or toe release in certain directions.
While some modern bindings, such as those produced by Look, offer multidirectional release mechanisms designed to mitigate twisting forces, no equipment is entirely fail-safe. Lichtman advises all skiers to ensure their DIN (Deutsches Institut für Normung) settings are professionally calibrated based on their height, weight, age, and skill level. He cautions against "cranking up" bindings to professional racing levels, as the average recreational skier does not require the same retention levels as an elite athlete like Breezy Johnson, who may be traveling at speeds exceeding 80 mph.
Implications for the Future of Alpine Safety
The broader impact of Dr. Lichtman’s work lies in the potential for standardized safety protocols within the ski industry. Currently, the lack of validated, industry-wide prevention programs means that many skiers take to the slopes without a clear understanding of the biomechanical risks.
The economic implications of these injuries are also substantial. With the average cost of ACL reconstruction and subsequent physical therapy ranging from $20,000 to $50,000, the "ounce of prevention" Lichtman advocates for represents a significant potential saving for both individuals and the healthcare system.
As the 2026 ski season approaches, with Lichtman set to accompany the U.S. Women’s Team to Lillehammer, Norway, the focus remains on education. By identifying the root causes of injuries—ranging from the 60-millisecond Slip-catch to the dangers of flat light—the medical community hopes to foster a culture of "fatigue awareness" and technical proficiency. For Dr. Lichtman, the ultimate success of his career will not be measured by the number of successful surgeries he performs, but by the number of skiers who remain on the mountain and out of his office.
