Single bout of vibration-induced hamstrings fatigue reduces quadriceps inhibition and coactivation of knee muscles after anterior cruciate ligament (ACL) reconstruction.

Persistent quadriceps strength deficits in individuals with anterior cruciate ligament reconstruction (ACLr) have been attributed to arthrogenic muscle inhibition (AMI). The purpose of the present study was to investigate the effect of vibration-induced hamstrings fatigue on AMI in patients with ACLr. Eight participants with unilateral ACLr (post-surgery time: M = 46.5, SD = 23.5 months; age: M = 21.4, SD = 1.4 years) and eight individuals with no previous history of knee injury (age: M = 22.5, SD = 2.5 years) were recruited. A fatigue protocol, consisting of 10 min of prolonged local hamstrings vibration, was applied to both the ACLr and control groups. The central activation ratio (CAR) of the quadriceps was measured with a superimposed burst of electrical stimulation, and hamstrings/quadriceps coactivation was assessed using electromyography (EMG) during isometric knee extension exercises, both before and after prolonged local vibration. For the ACLr group, the hamstrings strength, measured by a load cell on a purpose-built chair, was significantly (P = 0.016) reduced about 14.5%, indicating fatigue was actually induced in the hamstrings. At baseline, the ACLr group showed a trend (P = 0.051) toward a lower quadriceps CAR (M = 93.2%, SD = 6.2% versus M = 98.1%, SD = 1.1%) and significantly (P = 0.001) higher hamstrings/quadriceps coactivation (M = 15.1%, SD = 6.2% versus M = 7.5%, SD = 4.0%) during knee extension compared to the control group. The fatigue protocol significantly (P = 0.001) increased quadriceps CAR (from M = 93.2%, SD = 6.2% to M = 97.9%, SD = 2.8%) and significantly (P = 0.006) decreased hamstrings/quadriceps coactivation during knee extension (from M = 15.1%, SD = 6.2% to M = 9.5%, SD = 4.5%) in the ACLr group. In conclusion, vibration-induced hamstrings fatigue can alleviate AMI of the quadriceps in patients with ACLr. This finding has clinical implications in the management of recovery for ACLr patients with quadriceps strength deficits and dysfunction.

Pain and Anxiety Levels of Patients Undergoing Tissue Expansion After Mastectomies: A Case Series Study.

The tissue expansion process is done after mastectomies to increase the submuscular space in preparation for the placement of permanent breast implant. The process is often believed to be painful by patients who are often intimidated by the prospect of mechanically stretching out their skin and muscle. This study aims to quantify the pain experienced by patients and determine the different pain management techniques used. We used a case series approach, in which patients who were undergoing serial tissue expansion process were asked to rate their pain and anxiety on a scale from 1 to 10, using a questionnaire and the visual analog scale. Pain was rated during and after the expansion procedure, and patients were also surveyed to find the most commonly used and most effective pain management technique. Patients typically reported very little pain during and after the procedure, with an average of 0.4 to 2.5 pain experienced out of 10. The pain did not last, on average, longer than 1 day. Furthermore, the most widely used and most helpful pain medication was ibuprofen. During the tissue expansion procedure, the mean anxiety level was 0.64 (1.3). The findings show that tissue expansion process is a relatively low pain procedure and is not a contraindication for undergoing breast reconstruction. Ibuprofen, a mild treatment with few side effects, was efficacious in pain relief though most patients required no pain relief.

Maximal force and tremor changes across the menstrual cycle.

PURPOSE: Sex hormones have profound effects on the nervous system in vitro and in vivo. The present study examines the effect of the menstrual cycle on maximal isometric force (MVC) and tremor during an endurance task. METHODS: Nine eumenorrheic females participated in five study visits across their menstrual cycle. In each menstrual phase, an MVC and an endurance task to failure were performed. Tremor across the endurance task was quantified as the coefficient of variation in force and was assessed in absolute time and relative percent time to task failure. RESULTS: MVC decreases 23% from ovulation to the mid luteal phase of the menstrual cycle. In absolute time, the mid luteal phase has the highest initial tremor, though the early follicular phase has substantially higher tremor than other phases after 150 s of task performance. In relative time, the mid luteal phase has the highest level of tremor throughout the endurance task. CONCLUSIONS: Both MVC and tremor during an endurance task are modified by the menstrual cycle. Performance of tasks and sports which require high force and steadiness to exhaustion may be decreased in the mid luteal phase compared to other menstrual phases.

Quality of life in pediatric heart transplant recipients: a comparison with children with and without heart disease.

BACKGROUND: Little is known about the quality of life (QOL) of children with heart disease who undergo life-saving surgery. The aim of this multicenter study was to examine self- and parent-reported QOL outcomes in pediatric heart transplant recipients. METHODS: Pediatric heart transplant recipients/families (n = 174) from 7 transplant programs completed the Pediatric Quality of Life Inventory Generic Core Scales and Cardiac Module. Scores for the heart transplant sample were compared with non-transplant patients who had undergone conventional cardiac surgery and with a healthy child sample. Within the cardiac surgery group, heart disease/surgery was further categorized by severity/complexity. RESULTS: Heart transplant recipients were a mean age of 10.6 ± 4.7 years at a mean time post-transplant of 6.0 ± 4.1 years. By both self-report and parent proxy report, mean scores for heart transplant recipients were significantly lower than those in healthy children for physical and psychosocial QOL, including emotional and social functioning (p < 0.001), with 31.3% self-reporting significantly impaired psychosocial QOL scores. By self-report, there were no significant differences in emotional and social mean scores between the transplant and cardiac surgery groups. Transplant recipients reported significantly fewer cardiac symptoms than children with cardiac surgery (p < 0.01). Their self-reported school functioning scores were not significantly different from children with moderate to severe disease. CONCLUSION: Although pediatric heart transplant recipients experience significant symptomatic improvement, they remain at-risk for impaired psychosocial QOL, similar to children with residual or palliated heart disease. Assessment is needed to identify children at-risk and improve psychosocial outcomes.

Retransplantation of multiple organs: how many organs should one individual receive?

Every year, the transplant waiting list gets longer, while donor numbers essentially remain the same. This makes the responsibility of being good stewards of this precious and limited resource greater than ever. Transplant teams, who are both committed to their patients and aware of this important responsibility, are left to make the difficult and ethical decisions regarding retransplantation. Retransplantation of organs in pediatric patients presents a different set of issues to consider, and the results are promising. This case study presents a boy who received a kidney transplant for focal segmental glomerulosclerosis at age 5. At age 11, because of the recurrence of focal segmental glomerulosclerosis and severe cardiomyopathy, he required a rare combined kidney-heart transplant. At age 17, he developed chronic renal failure and posttransplant coronary artery disease, most likely related to a period of noncompliance, and required yet another combined kidney-heart transplant. He is currently alive and well 2 years after transplantation.