The effect of isolated gastrocnemius contracture and gastrocnemius recession on lower extremity kinematics and kinetics during stance

BACKGROUND

Isolated gastrocnemius contracture limits ankle dorsiflexion with full knee extension and is potentially problematic during mid-stance of gait when 10° of dorsiflexion and full knee extension are needed. It is during this time that patients with isolated gastrocnemius contracture may demonstrate altered kinematics and/or kinetics. When conservative management fails to resolve painful foot pathologies associated with non-spastic isolated gastrocnemius contracture, gastrocnemius recession surgery has been suggested to resolve contracture and improve function and strength. However, there are no published reports on lower extremity kinematics/kinetics in the non-spastic isolated gastrocnemius contracture population. Assessment of alterations in gait mechanics is necessary to examine the effects of this potential surgical intervention.

METHODS

Lower extremity kinematics and kinetics were assessed in 6 patients clinically diagnosed with isolated gastrocnemius contracture pre- and post-surgical recession compared with 33 healthy control participants.

FINDINGS

Pre-operatively, patients with isolated gastrocnemius contracture demonstrated significantly increased peak knee flexion angles and knee flexion moments during mid-stance. There were no differences in peak ankle dorsiflexion angle or peak plantar flexion moment. Gastrocnemius recession did not alter gait kinematics/kinetics following surgery. Joint kinematic strategies utilized to compensate for isolated gastrocnemius contracture varied minimally between participants with IGC; most employed a flexed knee strategy, while one participant utilized a reduced ankle dorsiflexion strategy.

INTERPRETATION

Select post-surgical gait mechanics were unaltered; however, gait mechanics were not similar between non-spastic isolated gastrocnemius contracture patients and healthy control participants. Surgical intervention for patients with isolated gastrocnemius contracture does not appear to create any negative gait adaptations; however, patients may benefit from gait retraining post-recession as maladaptive gait patterns persist post operatively.

P3-08-04: “How Important Is This for Me?” – The Role of Necessity Beliefs as Determinants of Breast Cancer Prevention Intentions among High-Risk Women

Background Women at elevated risk for breast cancer (BC) face complex risk management decisions. Understanding the determinants of pre-counselling risk management intentions would be useful to clinicians in helping high-risk women make their decisions. Across several medical conditions, the Necessity-Concerns Framework (NCF) has emphasized the role of patient’ beliefs about interventions offered to them as central to decision-making. In the NCF, beliefs are conceptualized as perceived personal need for an intervention (necessity) and as concerns about its perceived negative effects. To date, the NCF has not been applied to investigate decision-making in the high-risk setting. Our objective was to use the NCF to describe the risk management beliefs of high-risk women prior to initial consultation. The relative importance of BC fear, perceived susceptibility to BC and necessity-concerns beliefs in predicting prevention intentions was also examined.

Methods A survey was sent to patients prior to their first risk consultation. BC fear was assessed with Champion BC Fear Scale and perceived susceptibility was measured by asking women to rate their likelihood of developing BC (0 =definitely will not get it to 100=definitely will get it). For each of screening, lifestyle modifications, pharmacoprevention (PP) and prophylactic surgery (PS), women rated (1=strongly disagree to 5=strongly agree) their need for the option (e.g., my health in the future will depend on this option, this option will protect me from becoming worse), and its negative consequences (e.g. I worry about the long-term effects of this option, this option will disrupt my life). Intentions were assessed by asking how strongly (1=definitely not to 5=Definitely Yes) they intended to adopt each option. The planned sample size is 100 women and recruitment is on-going. We report data from 44 women who have completed the questionnaire.

Results: The majority intended to adopt screening (92%) and lifestyle (91%) compared to PP (23%) or PS (18%). Screening and lifestyle were associated with stronger intentions, higher perceived need, and lower concerns than PP and PS (all t-tests, p <0.0001). Hierarchical regression analyses revealed that perceived need predicted intentions for each option (all ps < 0.005, except for screening, p < .1) whereas concern beliefs were only correlated with PP intentions (β=-.398, p < .005). Fear of BC was related to PP intentions (β=.401, p < .005) and to intentions to remain smoke-free (β=-.341, p < .05). Perceived susceptibility did not contribute to intentions.

Conclusions Our preliminary findings are promising and suggest that the NCF is useful for understanding decision-making in the high-risk setting. The findings emphasize the importance of necessity beliefs in BC risk management decisions. For the group as whole, across each risk management option, the strongest predictor of intentions was a women's perception of her personal need for the option. Concerns about negative effects and BC fear played only a minor role and perceived susceptibility did not predict intentions. These observations stress the importance of making screening or prevention recommendations hand in hand with the individual beliefs and concerns.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-08-04.

Use of an evidence-based shift report tool to improve nurses' communication

Using steps in the Iowa Model of Evidence-Based Practice, nursing staff developed and piloted a standardized shift report tool on one medical-surgical unit in a large tertiary care hospital. Pilot outcomes showed shift reports with decreased frequency of missed information, fewer delays in shift starting time, and less use of overtime.

Lower extremity kinematics in runners with patellofemoral pain during a prolonged run

PURPOSE

Investigate lower extremity kinematics in runners with patellofemoral pain (PFP) syndrome during a prolonged run.

METHODS

For this study, 20 runners with PFP and 20 uninjured controls performed a prolonged run on a treadmill at a self-selected pace. The run ended based on HR, perceived exertion, or level of knee pain. Kinematic data were analyzed at the beginning and at the end of the run.

RESULTS

The PFP group demonstrated less peak knee flexion, peak hip adduction, eversion excursion, peak knee flexion velocity, peak hip adduction velocity, and peak hip internal rotation velocity compared with controls. A significant main effect for time indicated that increases in most kinematic variables occurred at the end of the run. Interestingly, five runners with PFP displayed atypical motions of knee valgus and eight displayed hip abduction during the first half of stance.

CONCLUSIONS

The PFP group as a whole displayed less overall motion compared with controls. This may be indicative of a strategy aimed at limiting lower extremity movement to reduce pain. However, increases in joint motion occurred at the end of the run where pain levels were greatest. Three distinct PFP subgroups were noted, and each demonstrated unique kinematic mechanisms that may be associated with PFP. In the knee valgus subgroup, increased knee valgus and decreased peak motions were noted in other joints. In the hip abduction subgroup, less knee flexion and motion overall was noted. In the subgroup that displayed typical first half patterns (knee and hip adduction), increased hip internal rotation and decreased knee internal rotation were observed. These results suggest that several different kinematic mechanisms related to PFP may exist.

Improving between-day kinematic reliability using a marker placement device

3D motion analysis is commonly used to measure clinical outcomes, involving repeated measures over time. However, the day-to-day reliability of these measurements has been questioned and few attempts have been made to improve this reliability. Our purpose was to determine if a marker placement device (MPD) could improve day-to-day kinematic reliability as compared to manual marker placement. Ten healthy runners participated. Day-to-day comparisons of peak angles were made between manual marker placement and the use of an MPD. Reliability of each method was determined with intraclass correlation coefficients (ICC) and standard errors of measurement (SEM). The ICC and SEM values improved with the MPD. With the MPD, 7 out of 9 ICC values were >0.9 compared to only 3 when using manual marker placement. Additionally, the largest reduction in SEM values was in the transverse plane. Use of the MPD increases the power to detect smaller differences in studies of where gait is assessed over time.

Epidemiology of influenza-associated hospitalization in adults, Toronto, 2007/8

The purpose of this investigation was to identify when diagnostic testing and empirical antiviral therapy should be considered for adult patients requiring hospitalization during influenza seasons. During the 2007/8 influenza season, six acute care hospitals in the Greater Toronto Area participated in active surveillance for laboratory-confirmed influenza requiring hospitalization. Nasopharyngeal (NP) swabs were obtained from patients presenting with acute respiratory or cardiac illness, or with febrile illness without clear non-respiratory etiology. Predictors of influenza were analyzed by multivariable logistic regression analysis and likelihoods of influenza infection in various patient groups were calculated. Two hundred and eighty of 3,917 patients were found to have influenza. Thirty-five percent of patients with influenza presented with a triage temperature >or=38.0 degrees C, 80% had respiratory symptoms in the emergency department, and 76% were >or=65 years old. Multivariable analysis revealed a triage temperature >or=38.0 degrees C (odds ratio [OR] 3.1; 95% confidence interval [CI] 2.3-4.1), the presence of respiratory symptoms (OR 1.7; 95% CI 1.2-2.4), admission diagnosis of respiratory infection (OR 1.8; 95% CI 1.3-2.4), admission diagnosis of exacerbation of chronic obstructive pulmonary disease (COPD)/asthma or respiratory failure (OR 2.3; 95% CI 1.6-3.4), and admission in peak influenza weeks (OR 4.2; 95% CI 3.1-5.7) as independent predictors of influenza. The likelihood of influenza exceeded 15% in patients with respiratory infection or exacerbation of COPD/asthma if the triage temperature was >or=38.0 degrees C or if they were admitted in the peak weeks during the influenza season. During influenza season, diagnostic testing and empiric antiviral therapy should be considered in patients requiring hospitalization if respiratory infection or exacerbation of COPD/asthma are suspected and if either the triage temperature is >or=38.0 degrees C or admission is during the weeks of peak influenza activity.

The effect of real-time gait retraining on hip kinematics, pain and function in subjects with patellofemoral pain syndrome

BACKGROUND

Patellofemoral pain syndrome (PFPS) is the most common overuse injury in runners. Recent research suggests that hip mechanics play a role in the development of this syndrome. Currently, there are no treatments that directly address the atypical mechanics associated with this injury.

OBJECTIVE

The purpose of this study was to determine whether gait retraining using real-time feedback improves hip mechanics and reduces pain in subjects with PFPS.

METHODS

Ten runners with PFPS participated in this study. Real-time kinematic feedback of hip adduction (HADD) during stance was provided to the subjects as they ran on a treadmill. Subjects completed a total of eight training sessions. Feedback was gradually removed over the last four sessions. Variables of interest included peak HADD, hip internal rotation (HIR), contralateral pelvic drop, as well as pain on a verbal analogue scale and the lower-extremity function index. We also assessed HADD, HIR and contralateral pelvic drop during a single leg squat. Comparisons of variables of interest were made between the initial, final and 1-month follow-up visit.

RESULTS

Following the gait retraining, there was a significant reduction in HADD and contralateral pelvic drop while running. Although not statistically significant, HIR decreased by 23% following gait retraining. The 18% reduction in HADD during a single leg squat was very close to significant. There were also significant improvements in pain and function. Subjects were able to maintain their improvements in running mechanics, pain and function at a 1-month follow-up. An unexpected benefit of the retraining was an 18% and 20% reduction in instantaneous and average vertical load rates, respectively.

CONCLUSIONS

Gait retraining in individuals with PFPS resulted in a significant improvement of hip mechanics that was associated with a reduction in pain and improvements in function. These results suggest that interventions for PFPS should focus on addressing the underlying mechanics associated with this injury. The reduction in vertical load rates may be protective for the knee and reduce the risk for other running-related injuries.