Neuromuscular Activation in Conventional Therapeutic Exercises and Heavy Resistance Exercises: Implications for Rehabilitation

Abstract

Background and Purpose. Central activation failure and muscular atrophy are common after knee joint injury. Thus, exercises that aim to stimulate muscular hypertrophy and increase neural drive to the muscle fibers should be used during rehabilitation. This study examined the level of knee joint neuromuscular activation during 4 conventional therapeutic exercises (quadriceps femoris muscle setting, manual lateralization of the patella, rhythmic stabilization, and the pelvic bridging exercise) and 4 heavy resistance exercises (free-weight squat with a barbell, horizontal seated leg press, isolated knee extension with a cam mechanism, and isolated hamstring muscle curl) in young, untrained men who were healthy. Subjects. Thirteen male subjects (mean age=25.3 years, SD=3.0) with no previous history of knee injury participated in the study. Methods. Neuromuscular activation during the exercises was defined as the root-mean-square (RMS) electromyographic (EMG) signal normalized to the peak RMS EMG signal of a maximal isometric muscle contraction. Results. Low levels of neuromuscular activation were found during all conventional exercises (<35%). A limitation may be that only a few of many different conventional exercises were investigated. The highest level of neuromuscular activation (67%–79%) was observed during the open kinetic chain resistance exercises (isolated knee extension and hamstring muscle curl). None of the conventional exercises or heavy resistance exercises were found to preferentially activate the vastus medialis muscle over the vastus lateralis muscle. Discussion and Conclusion. The results indicate that heavy resistance exercises should be included in rehabilitation programs to induce sufficient levels of neuromuscular activation to stimulate muscle growth and strength.

Early Progressive Strength Training to Enhance Recovery After Fast‐Track Total Knee Arthroplasty: A Randomized Controlled Trial

“…The strength training exercises in the PST group were chosen to restore quadriceps muscle strength specifically because the substantial loss of knee extension strength is well described () and relates to reduced functional performance after TKA (). The rationale of our 2 strength training exercises was that seated knee extension targets the quadriceps muscle specifically () and performing knee extensions until contraction failure increases neural activation of the quadriceps muscle during the set while fatigue develops in healthy subjects (). The leg press exercise involves the activation of several other lower‐extremity muscles with reported strength deficits following TKA () in addition to activating the quadriceps muscle (), and leg press power relates to functional performance early after TKA ().…”

Electromyographic Activities of Cervical Muscles While Using an Oscillating Blade Held in the Mouth: Influence of Different Swings

“…In the both tasks, motion in the participant's neck must be minimized to achieve oscillation at its natural frequency; excessive neck movement interferes with coordination necessary to isolate reciprocal motion to the head (5, 7), and coordinately induced "low" muscle activity of the sternocleidomastoid and cervical extensor muscles (11). The intensity of both cervical muscles may be suitable in providing endurance and stability (12).…”

“…A previous study classified muscle activity of 0% to 20% of the MVC (%) as "low", 21 to 40% as "moderate", 41 to 60% as "high", and greater than 60% as "very high" (11). Additionally, a muscle activity of more than 40% -60% indicates a muscle strengthening stimulus (12). To obtain a muscle endurance capacity or to maintain stability is less than 25% (12).…”

“…Additionally, a muscle activity of more than 40% -60% indicates a muscle strengthening stimulus (12). To obtain a muscle endurance capacity or to maintain stability is less than 25% (12). However, there is no study about the activities of the cervical muscles while using an oscillating blade held in the mouth.…”

Isokinetic profile of subjects with the ruptured anterior cruciated ligament

“…Nevertheless, the knee joint is still in the focus though not in such an extent. The reason could be successful surgery and rehabilitation protocols after injury [15][16][17] .…”