Pain and Effusion and Quadriceps Activation and Strength

Abstract

Context: Quadriceps dysfunction is a common consequence of knee joint injury and disease, yet its causes remain elusive.Objective: To determine the effects of pain on quadriceps strength and activation and to learn if simultaneous pain and knee joint effusion affect the magnitude of quadriceps dysfunction.Design: Crossover study. Setting: University research laboratory.Patients or Other Participants: Fourteen (8 men, 6 women; age ¼ 23.6 6 4.8 years, height ¼ 170.3 6 9.16 cm, mass ¼ 72.9 6 11.84 kg) healthy volunteers.Intervention(s): All participants were tested under 4 randomized conditions: normal knee, effused knee, painful knee, and effused and painful knee.Main Outcome Measure(s): Quadriceps strength (Nm/kg) and activation (central activation ratio) were assessed after each condition was induced.Results: Quadriceps strength and activation were highest under the normal knee condition and differed from the 3 experimental knee conditions (P , .05). No differences were noted among the 3 experimental knee conditions for either variable (P . .05).Conclusions: Both pain and effusion led to quadriceps dysfunction, but the interaction of the 2 stimuli did not increase the magnitude of the strength or activation deficits. Therefore, pain and effusion can be considered equally potent in eliciting quadriceps inhibition. Given that pain and effusion accompany numerous knee conditions, the prevalence of quadriceps dysfunction is likely high.Key Words: arthrogenic muscle inhibition, central activation failure, voluntary activation, muscles Key PointsKnee pain and effusion resulted in arthrogenic muscle inhibition and weakness of the quadriceps. The simultaneous presence of pain and effusion did not increase the magnitude of quadriceps dysfunction. To reduce arthrogenic muscle inhibition and improve muscle strength, clinicians should employ interventions that target removing both pain and effusion.

The Time Course of Knee Swelling Post Total Knee Arthroplasty and Its Associations with Quadriceps Strength and Gait Speed

“…In the present study, the observed knee swelling-quadriceps strength association persisted in multivariable models adjusted for knee pain intensity, and these findings seem to corroborate those from previous experimental studies which have demonstrated a link between relatively pain-free knee swelling and reduced voluntary quadriceps activation [5][6][7][8][9][10]. In the context of patients with TKA, independent of knee pain [26], voluntary muscle activation was found to be a determinant of quadriceps strength [26,27].…”

“…Because quadriceps weakness is a major contributor to gait speed limitations in TKA [2,4] and because experimental studies in healthy volunteers have demonstrated a putative link between knee swelling and quadriceps strength [5][6][7][8][9][10], understanding the associations between knee swelling, quadriceps strength, and gait limitations in TKA is crucial. Thus, the present study uniquely used bioimpedance spectrometry to quantify knee swelling in patients with TKA and it aimed to (i) describe the time course of knee swelling over a 3-month post-TKA period and (ii) examine the longitudinal associations of knee swelling with quadriceps strength and gait speed.…”

Brain Activation for Knee Movement Measured Days Before Second Anterior Cruciate Ligament Injury: Neuroimaging in Musculoskeletal Medicine

“…1,2 The contralateral knee may be at greater risk of injury than the involved knee, 2 suggesting possible postinjury bilateral neurologic alterations or the presence of bilateral factors that contributed to the initial injury. 3 Researchers have reported that these postinjury neurologic differences include disrupted central nervous system afferent function, 4,5 altered efferent output, 3,6 and changes in brain activity for motor control. 7,8 Few investigators have prospectively studied the neurologic changes that occur in the brain after ACL injury, reconstruction, and rehabilitation and before subsequent injury.…”

Comparison of Transcutaneous Electrical Nerve Stimulation and Cryotherapy for Increasing Quadriceps Activation in Patients With Knee Pathologies

“…13 Therefore, given the inflammatory status of the patient being treated, clinicians may elect to use 1 of the disinhibitory modalities over the other. Patients with chronic knee pathologies who demonstrate quadriceps activation failure should be instructed to use TENS more than cryotherapy, unless they are attempting to control the onset of swelling and inflammation after exercise or activity.…”