Quadriceps Femoris and Hamstring Muscle Function in a Person With an Unstable Knee

Abstract

Background and Purpose. The purpose of this case report is to describe the evaluation, treatment, and short-term outcome for an individual with chronic, progressively worsening instability of the knee during gait associated with anterior cruciate ligament (ACL) insufficiency. Case Description. The patient was a 34-year-old man who sustained bilateral ACL injuries. Subsequently, an autograft reconstruction of the left knee ACL was performed. Eight months post-reconstruction, the left knee was unstable despite bracing. Gait analysis and tests to determine the presence of muscle inhibition were performed prior to and after 12 weeks of training. Isometric torque of the knee extensors and flexors was measured with the knee in 90 degrees of flexion. A training program primarily consisted of electromyographic biofeedback during thigh muscle exercises, balance exercises, and gait. Outcomes. Muscle inhibition decreased and maximal isometric knee flexion and extension torques increased during the 12-week training period. Gait analysis demonstrated a 50% decrease in the maximum knee extensor moment and an increase in walking speed. Discussion. Selected gait variables, torque production, and muscle inhibition may change in a person with an unstable knee. The measurement of variables that have previously been documented as mechanisms of knee instability during walking allows for the selection of a specific treatment approach. ͓Maitland ME, Ajemian SV, Suter E. Quadriceps femoris and hamstring muscle function in a person with an unstable knee. Phys Ther. 1999;79:66 -75 1 Because the ACL is the primary connective tissue constraint to anterior translation of the tibia on the femur, increased tibiofemoral joint laxity was found with passive displacement tests 2 and isolated quadriceps femoris muscle contraction. 3 During gait, a person with an ACL-deficient knee may also respond to external forces by using muscles for stability.There is evidence that muscular control of knee joint stability is impaired following an ACL injury. 4 -6 Hamstring muscle contractions in response to postural perturbations, for example, were found to be slower, 4 postural sway during one-leg standing was found to be greater, 5 and the threshold to detect passive motion of the knee joint was found to be decreased 6 in subjects with ACL deficiencies compared with uninjured subjects. Disability in people following an ACL injury may be caused by changes in muscular control. 7 Persistent muscle weakness has been attributed to patients' inability to voluntarily activate the muscles. 8 Researchers have described associations between the inability to control the activity of the quadriceps femoris muscles and pain, 8 joint effusion, 9 immobilization, 10 and altered joint receptor function. 7 We are not aware of any studies in which the influence of other potential sources of muscle inhibition, such as psychological and emotional aspects, are documented.The evaluation of knee dysfunction in people with possible problems in motor control presents a c...

Arthrogenic Muscle Inhibition: Best Evidence, Mechanisms, and Theory for Treating the Unseen in Clinical Rehabilitation

“…115,116 Studies report large magnitude increases in quadriceps strength secondary to EMG biofeedback isometric training in individuals with ACLR and knee OA. [117][118][119][120][121] Both immediate (single bout) 116,117 and training effects (6-8 wk of intervention) 118,120,121 are reported. Although there is a lack of definitive evidence supporting EMG biofeedback over exercise alone, 122 it is worth noting that other forms of muscle-directed biofeedback, such as musculoskeletal ultrasound, are reported to have similar effects in those with knee OA.…”

Targeting Quadriceps Inhibition with Electromyographic Biofeedback: A Neuroplastic Approach

“…The use of EMGBF in conjunction with exercise has been reported to positively affect both quadriceps activation 18,21,65,66 and strength. [18][19][20]22,23,[66][67][68] In a study that assessed the effectiveness of EMGBF in postoperative patients who underwent meniscectomy, their quadriceps activation was increased 10fold compared to patients who performed standard rehabilitation. Likewise, Maitland et al 66 conducted a case study of a patient who was 8 months after ACL reconstruction and reported progressively declining knee stability.…”

“…[18][19][20]22,23,[66][67][68] In a study that assessed the effectiveness of EMGBF in postoperative patients who underwent meniscectomy, their quadriceps activation was increased 10fold compared to patients who performed standard rehabilitation. Likewise, Maitland et al 66 conducted a case study of a patient who was 8 months after ACL reconstruction and reported progressively declining knee stability. They found that by incorporating EMGBF into a closed kinetic chain rehabilitation program, the patient's quadriceps activation was improved by 52% and their peak torque during knee extension was increased by 203%.…”

Play at Your Own Risk: Sport and the Injury Epidemic

“…A difference in activation patterns between quadriceps and hamstrings has been demonstrated. Adjustments in neuromuscular factors due to injury may contribute to the more obvious impairments, such as strength loss, atrophy, and altered function (Chmielewski, Stackhouse, Axe, & Snyder-Mackler, 2004;Drechsler, Cramp, & Scott, 2006;Maitland, Ajemian, & Suter, 1999;McHugh, Tyler, Nicholas, Browne, & Gleim, 2001;Swanik, Lepart, Giraldo, DeMont, & Fu, 1999; Snyder-Mackler, De Luca, Williams, Eastlack, & Bartolozzi, Individual cycle lengths were normalized for a 28-day cycle for these graphical purposes (Wojtys et al, 2002). 1994; Urbach, Nebelung, Becker, & Awiszus, 2001;Urbach, Nebelung, Weiler, & Awiszus, 1999).…”