Both TENS and focal knee joint cooling increased the quadriceps CAR immediately after application in participants with tibiofemoral osteoarthritis.

Context: More than 1.6 million sport-related concussions occur every year in the United States, affecting greater than 5% of all high school athletes who participate in contact sports. As more females participate in sports, understanding possible differences in concussion symptoms between sexes becomes more important.Objective: To compare symptoms, symptom resolution time, and time to return to sport between males and females with sport-related concussions.Design: Descriptive epidemiology study. Setting: Data were collected from 100 high schools via High School RIO (Reporting Information Online).Patients or Other Participants: Athletes from participating schools who sustained concussions while involved in interscholastic sports practice or competition in 9 sports (boys' football, soccer, basketball, wrestling, and baseball and girls ' soccer, volleyball, basketball, and softball) Main Outcome Measure(s): Reported symptoms, symptom resolution time, and return-to-play time.Results: No difference was found between the number of symptoms reported (P 5 .30). However, a difference was seen in the types of symptoms reported. In year 1, males reported amnesia (exact P 5 .03) and confusion/disorientation (exact P 5 .04) more frequently than did females. In year 2, males reported more amnesia (exact P 5 .002) and confusion/ disorientation (exact P 5 .002) than did females, whereas females reported more drowsiness (exact P 5 .02) and sensitivity to noise (exact P 5 .002) than did males. No differences were observed for symptom resolution time (P 5 .40) or return-to-play time (P 5 .43) between sexes.Conclusions: The types of symptoms reported differed between sexes after sport-related concussion, but symptom resolution time and return-to-play timelines were similar.

Context: Return to activity in the presence of quadriceps dysfunction may predispose individuals with anterior cruciate ligament reconstruction (ACLR) to long-term joint degeneration. Asymmetry may manifest during movement and result in altered knee-joint-loading patterns; however, the underlying neurophysiologic mechanisms remain unclear.Objective: To compare limb symmetry of quadriceps neuromuscular function between participants with ACLR and participants serving as healthy controls.Design: Descriptive laboratory study. Setting: Research laboratory. Patients or Other Participants: A total of 22 individuals with ACLR (12 men, 10 women) and 24 individuals serving as healthy controls (12 men, 12 women).Main Outcome Measure(s): Normalized knee-extension maximal voluntary isometric contraction (MVIC) torque (Nm/ kg), quadriceps central activation ratio (CAR) (%), quadriceps motor-neuron-pool excitability (Hoffmann reflex to motor wave ratio), and quadriceps active motor threshold (AMT) (% 2.0 T) were measured bilaterally and used to calculate limb symmetry indices for comparison between groups. We used analyses of variance to compare quadriceps Hoffmann reflex to motor wave ratio, normalized knee-extension MVIC torque, quadriceps CAR, and quadriceps AMT between groups and limbs.Results: The ACLR group exhibited greater asymmetry in knee-extension MVIC torque (ACLR group ¼ 0.85 6 0.21, healthy group ¼ 0.97 6 0.14; t 44 ¼ 2.26, P ¼ .03), quadriceps CAR (ACLR group ¼ 0.94 6 0.11, healthy group ¼ 1.00 6 0.08; t 44 ¼ 2.22, P ¼ .04), and quadriceps AMT (ACLR group ¼ 1.13 6 0.18, healthy group ¼ 1.02 6 0.11; t 34 ¼À2.46, P ¼ .04) than the healthy control group.Conclusions: Asymmetries in measures of quadriceps function and cortical excitability were present in patients with ACLR. Asymmetry in quadriceps strength, activation, and cortical excitability persisted in individuals with ACLR beyond return to recreational activity. Measuring the magnitude of asymmetry after ACLR represents an important step in understanding long-term reductions in self-reported function and increased rate of subsequent joint injury in otherwise healthy, active individuals after ACLR.Key Words: quadriceps activation, limb symmetry index, transcranial magnetic stimulation Key PointsThe anterior cruciate ligament reconstruction (ACLR) group exhibited a weaker, less activated quadriceps and less cortical excitability in the reconstructed limb than in the contralateral limb and in the limbs of the healthy control group. Asymmetry in quadriceps strength, activation, and cortical excitability persisted in individuals with ACLR beyond return to recreational activity. Chronic asymmetry indicated reduced dynamic force absorption at the knee and may explain the increased rate of knee reinjury and chronic joint degeneration after ACLR.

[ literature review ] P ostoperative weakness, muscle atrophy, and impaired knee function are common following anterior cruciate ligament (ACL) reconstruction. During the first 4 weeks after surgery, significant quadriceps strength deficits, when compared to the contralateral limb, have been reported. 26,28 Although knee stability is significantly improved, long-term outcomes report knee extensor weakness ranging from 6% 12 to 18% 23 as late as 1 to 6 years following reconstruction. Ernst et al 8 further demonstrated that persistent lower extremity compensations exist following ACL reconstruction and adversely affect single-limb performance, including vertical jump takeoff and landing. Other investigators 12 found that patients following ACL reconstruction who had knee extensor strength less than 80% of the contralateral side had gait kinematics similar to patients with ACL-deficient knees. In the same study, patients with knee extensor strength greater than 90% of the contralateral limb demonstrated gait kinematics similar to healthy individuals without ACL injury.12 A clear challenge for the rehabilitation specialist treating patients who have undergone ACL reconstruction is the resolution of the quadriceps strength deficit through the safest and most expeditious means available.Neuromuscular electrical stimulation (NMES) applied to the quadriceps is used in the clinical rehabilitation of quadriceps weakness following ACL reconstruction. 18Some investigators initiate NMES on the third postoperative day 21 t MeTHodS: Searches were performed for randomized controlled trials using electronic databases from 1966 through October 2008. Methodological quality was assessed using the Physiotherapy Evidence Database Scale. Betweengroup effect sizes and 95% confidence intervals (CIs) were calculated.t reSulTS: Eight randomized controlled trials were included. The average Physiotherapy Evidence Database Scale score was 4 out of possible maximum 10. The effect sizes for quadriceps strength measures (isometric or isokinetic torque) from 7 studies ranged from -0.74 to 3.81 at approximately 6 weeks postoperatively; 6 of 11 comparisons were statistically significant, with strength benefits favoring NMES treatment. The effect sizes for functional performance measures from 1 study ranged from 0.07 to 0.64 at 6 weeks postoperatively; none of 3 comparisons were statistically significant, and the effect sizes for self-reported function measures from 1 study were 0.66 and 0.72 at 12 to 16 weeks postoperatively; both comparisons were statistically significant, with benefits favoring NMES treatment.t ConCluSion: NMES combined with exercise may be more effective in improving quadriceps strength than exercise alone, whereas its effect on functional performance and patient-oriented outcomes is inconclusive. Inconsistencies were noted in the NMES parameters and application of NMES.t leVel oF eVidenCe: Therapy, level 1a-.

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