Eliminating the Weight-shift in the Post-Operative ACL Knee Athlete

Eliminating the Weight-shift in the Post-Operative ACL Knee Athlete

Robert A. Panariello MS, PT, ATC, CSCS

Founding Partner, Chief Clinical Officer

Professional Physical Therapy

Professional Athletic Performance Center

New York, New York


Kinesiophobia. It’s a very familiar term to the sports medicine and sports rehabilitation health care professional. With specific regard to the post-operative anterior cruciate ligament reconstruction (ACLR) knee athlete, kinesiophobia is a significant consequential phenomena of the athlete’s lower extremity injury and/or surgery. Kinesiophobia has been noted to prohibit an ACLR athlete’s return to their previous level of athletic performance, if allowing a return to their sport of participation at all.

Kinesiophobia is the fear of the athlete inducing pain and/or re-injury to their ACLR knee resulting in a compromised physical performance that occurs during physical rehabilitation, athletic performance enhancement training, as well as game day competition. How serious is kinesiophobia in the athletic ACLR population? It is reported of the more than 200,000+ ACL reconstructions that occur annually in the United States, 20% to 50% will not return to the same sport of participation after surgery and 10% to 70% of those who return to sports participation will do so at a substandard level of performance (1, 2). Other investigators reporting an in-depth meta-analysis on this subject matter have stated only a 47% return to previous levels of sport participation several years after primary ACLR (3). It has also been reported that younger athletes (less than the age of 20 years) who experience a second ACL injury also had lower “psychological readiness” measured at 12 months after ACLR (4).The onset of kinesiophobia has been shown to occur early during the rehabilitation process (the initial 4 – 8 weeks), and has been reported to have a high rate of prevalence (61%) in the athletic ACLR population (5).

It is apparent that kinesiophobia has a significant influence upon the athlete’s demonstrated physical performance during their rehabilitation, athletic enhancement performance training, and return to sport competition. Planned efforts must transpire to avoid or resolve this condition during the physical rehabilitation process to ensure an optimal return to play for athletic competition.


Eliminating Body Weight-Shift During Early Stage ACLR Rehabilitation Exercise Performance


When addressing the ACLR athlete’s rehabilitation program, it is important to initiate the execution of exercises in the standing weight bearing closed kinetic chain (CKC) position as early and safely as possible. This is not only for the purpose of an “unaccustomed” stress application to the ACLR extremity for “adaptation” to transpire, but to also initiate the ability for the ACLR extremity to accept load as well as react to the ground surface area. “Loading” is not only imperative for the enhancement of the physical qualities necessary for neuromuscular adaptation and a return to optimal athletic performance, but also for the adaptation of muscle-tendon complex that is critical for re-establishing the stretch shortening cycle (SSC) and elastic (i.e. plyometric type) abilities. Restoration of the athlete’s musculotendon qualities includes reestablishing the athlete’s ability to produce as well as their acceptance of ground reaction force capabilities for the eventual achievement of optimal elastic, reactive, and deceleration competences. This is especially true of the ACLR athlete where the autograph ligament is likely harvested from the patella, hamstring, or quadriceps tendons.

Of the various bi-lateral CKC exercises available for addressing the athlete’s weight shift phenomenon, we prefer and incorporate the squat exercise (pattern) early in the rehabilitation process. The choice of this particular exercise includes, but is not limited to, the following advantages:

  • The bi-lateral squat exercise is recognized to enhance the physical quality foundation of strength which correlates to improved vertical jump, sprint, and athletic performance. Enhanced strength levels also afford knee joint stability via muscular contribution avoiding the phenomenon of “ligament dominance” that is present in weaker athletes.
  • Bi-lateral lower extremity exercises provide a more stable base of support and may reduce the fear/concern (i.e. kinesiophobia) of “loaded” exercise execution as well as achieving the athlete’s confidence during the performance of the prescribed exercise
  • Many activities of daily living utilize a squat movement pattern (i.e. sitting in and out of a chair, picking objects from the ground, etc.)
  • The bi-lateral squat pattern mimics the athletic “ready position” taught by sport coaches
  • Most athletic endeavors begin and end on two feet
  • Greater exercise executed intensities (loads) and higher initial exercise velocities are achieved on two feet
  • The appropriate squat pattern exercise progression will eventually lead to the achievement of a successful overhead squat pattern resulting in increased joint mobility, enhanced soft tissue compliance, and improved body movement, awareness, and stability

The athlete may often express and/or demonstrate a fear of loading their ACLR extremity when asked to perform various weight-bearing exercises. This apprehension is demonstrated during the squat exercise execution as the athlete performs a “Trendelenburg squat” so to speak, by laterally shifting their body weight away from the ACLR extremity and toward the non-operative lower extremity. A previously published technique I have utilized for over 30 years to successfully correct this weight shifting pattern is to “post” the non-operative extremity upon a box or raised surface of a specific height (6, 7).

The height of the surface utilized to post the non-involved extremity will correlate to the height of the athlete. A taller athlete will require a higher box or elevated surface and vice versa. When selecting an elevated surface (i.e. box) for the elimination of the athletes weight shift, a height of 2 to 4 inches may initially be prescribed (Figure 6).

Figure 6 Posting of the Non-Operative Lower Extremity (Left Leg) to Eliminate Lateral Weight Shifting Away from the Post-Operative ACLR (Right Leg) Lower Extremity

By “posting” (i.e. raising) the non-operative extremity it becomes more difficult for the athlete to shift their body weight away from the ACLR lower extremity during the execution of the body weight squat exercise. As the body weight shift is corrected, a greater load and application of stress is now placed upon the ACLR extremity for “adaptation” to occur (8).

Recent research (8) comparing the ACLR traditional squat exercise to ACLR “posting” squat exercise has demonstrated the following:

  • Knee extensor net joint moments were lower in the ACLR extremity (due to reoccurring body weight shifting) when compared with the non-involved lower extremity during normal (level ground height) bi-lateral squat exercise performance
  • Individuals with ACLR exhibit knee extensor asymmetry (body weight shifting) during bi-lateral squat exercise performance
  • Knee extensor net joint moments were greater in the ACLR extremity and lower in the “posted” (elevated) non-involved lower extremity during the bi-lateral squat performance

The repeated “posted” squat exercise execution resulting in greater ACLR loading and muscle activity as well as the athlete’s increasing confidence of accepting load will also assist to minimize if not eliminate the presence of kinesiophobia. The athlete is continually “coached” until the time a technically proficient body weight “posted” squat exercise pattern is achieved. At the time of this achievement the non-involved extremity surface (box) height is progressively lowered by 1 inch increments until the time the athlete can demonstrate a proper body weight squat pattern performed upon a level ground surface area.

Prescribing an exercise intensity greater than body weight is not recommended during this elevated (posted) lower extremity squat exercise performance. The application of additional external loads may place unwarranted stress at the sacroiliac (SI) joint, an anatomical joint structure responsible for approximately 30% of all low back pain. The prescribed application of an increased external load may be appropriate at the time the athlete has demonstrated an appropriately executed squat exercise pattern, including exercise depth, upon a level ground surface as determined by the rehabilitation professional. External exercise intensities may be applied from the “top-down” i.e. back squat, front squat, box squat, etc. or from the “bottom-up” i.e. trap bar deadlift, barbell deadlift, dumbbell deadlift, etc. depending upon the specific exercise that is determined to be best suited for the ACLR athlete.



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  6. Panariello RA, “If Your Post-Operative Knee Athlete Lacks Confidence, Post Them Up” com 2010
  7. Panariello RA, Stump TJ, and Maddalone D, “Postoperative Rehabilitation and Return to Play After Anterior Cruciate Ligament Reconstruction”, Oper Tech Sports Med, 2015; 24:35-44
  8. Jean, LMY and Chiu, LZF, “Elevating the Noninvolved Limb Reduces Knee Extensor Asymmetry During Squat Exercise in Persons With Reconstructed Anterior Cruciate Ligament”, J Strength Cond Res, 2020; 34(8):2120-2127