Scott M. Monfort

Association Between Ball-Handling Versus Defending Actions and Acute Noncontact Lower Extremity Injuries in High School Basketball and Soccer

Background: High school–sponsored athletic programs currently provide more than 7.7 million students in the United States with health and societal benefits, but they also inherently increase the risk of students sustaining a sports injury. Understanding risk factors that predict injuries in sports is an essential first step to addressing the problem in this population. Purpose: To determine the role of offensive versus defensive actions in noncontact lower extremity injury rates in high school basketball and soccer in both boys’ and girls’ sports. Study Design: Descriptive epidemiological study. Methods: Noncontact lower extremity injury data were collected from academic years 2005-2006 through 2011-2012 for boys’ and girls’ basketball and soccer through the surveillance tool High School RIO (reporting information online). The injuries in this subset of the database occurred over a total of 6.4 million athlete-exposures. Results: Significant differences in overall lower extremity injury rates were found when comparing ball-handling and defending actions in basketball (rate ratio [RR], 1.36; 95% CI, 1.08-1.73; P = .009), but no appreciable difference was observed in soccer (RR, 0.89; 95% CI, 0.70-1.12; P = .31). Female participants had higher injury rates than did males for both ball-handling and defending actions for both sports (P < .05). Only girls’ soccer showed significant differences in the odds ratio (OR) of defending to ball-handling injury rates between competition and practice (OR, 1.88; 95% CI, 1.01-3.48; P = .047). Conclusion: The injury rate differences observed in this study between offensive and defensive actions suggest that investigating potential differences between sport-specific tasks may provide a more complete understanding of injury mechanisms.

Natural history of postural instability in breast cancer patients treated with taxane-based chemotherapy: A pilot study

Over 230,000 new cases of breast cancer are expected to be diagnosed in the United States in 2015. Taxane-based chemotherapy is often an effective treatment, but can also cause adverse symptoms in patients due to neurotoxicity. These side effects can impair postural control in patients; however, this instability has scarcely been quantified. The purpose of this pilot study was to gain insight into the natural history of postural instability in breast cancer patients being treated with taxane-based chemotherapy. Thirty-two breast cancer patients (31 female/1 male; 47.6±11.2 year; 16 stage II/16 stage III) completed eyes open and eyes closed quiet standing trials in the oncology clinic where they were being treated. These trials were collected at five timepoints throughout their chemotherapy treatment: (1) before initiating chemotherapy to provide a baseline, (2-4) before starting subsequent chemotherapy cycles, and (5) 1-3 months after receiving their last taxane infusion. After the first chemotherapy cycle, patients demonstrated increases in 95% confidence ellipse area of center of pressure (CoP) [45.2%, p=0.01] and root mean squared CoP excursion [18%, p=0.006] compared to baseline values for the eyes closed condition. These balance deficiencies progressed with cumulative taxane exposure. Postural instability persisted 1-3 months after completing chemotherapy with increases in 95% CoP ellipse area [86.8%, p=0.002], root mean squared CoP excursion [32.6%, p=0.001], and mean CoP velocity [30.4%, p=0.024]. The balance impairments demonstrated by patients in this study appear to be clinically relevant when compared to balance impairments previously reported in other patient populations.

Characterizing within-subject variability in quantified measures of balance control: A cohort study

BACKGROUND To longitudinally assess individuals using quantified measures, we must characterize within-subject variability (WSV) of the measures. RESEARCH QUESTION What is the natural within-subject variability (WSV) that can be expected in postural control over 3+ days? METHODS Thirteen individuals without orthopedic or neurologic impairment (mean(SD) = 55 (9) years; 76 (18) kg; 11 females/2 males) were recruited from a community workplace and consented to participate. Participants stood quietly with eyes closed (QEC) on a force platform (5 x 1 min x 6 days) in two stances: comfortable and narrow. We recorded center of pressure (COP) and calculated COP-based balance parameters. To analyze variance components, we applied a linear mixed model for repeated measures, calculating within-subject standard deviation (SDws) from the pooled variance not attributable to between-subject variability. To estimate WSV, we scaled SDws by a confidence interval (CI) factor (e.g. WSV at the 95%CI = WSV95 = SDws * 1.96) and report WSV95 for a range of conditions previously reported in the literature and the following measures previously found sensitive to or predictive of health: (primary) WSV95 of root-mean square amplitude of medial-lateral COP during QEC (RMSml); (secondary) WSV95 of COP ellipse area (COPa); (secondary) WSV95 of mean medial-lateral COP velocity (COPvml) during QEC. RESULTS WSV95 was estimated at RMSml = 0.8 mm, COPa = 99mm2, and COPvml = 1.1 mm/s among healthy, middle-aged participants standing comfortably for one recommended data duration (4 × 30 s trials). A look up table provides values for alternate protocols that have been suggested in the literature and might prove relevant for clinical translation. SIGNIFICANCE This work advances longitudinal assessment of individuals using quantified measures of postural control. Results enable practitioners/researchers to assess an individuals progress, maintenance, or decline relative to WSV at a defined CI level.

Abstract P1-09-04: Longitudinal evaluation of taxane-induced neuropathy in early stage breast cancer

Introduction Chemotherapy-induced peripheral neuropathy (CIPN) is a dose-limiting toxicity of several chemotherapy drug classes, including taxanes. Peripheral neuropathies have been shown to lead to pain, falls, and difficulty in walking and performing activities of daily living in a variety of patient populations. Although the prevalence of CIPN has been noted in cancer patients, the development of self-reported symptoms, gait changes and balance changes during treatment have not been well explored to date. We hypothesized that the use of taxane-based chemotherapy will result in significant changes in spatiotemporal gait and balance parameters, as well as self-reported quality of life and function. Methods We characterized the alterations in gait and balance that occur in non-metastatic breast cancer patients during taxane chemotherapy. We evaluated (1) spatiotemporal gait parameters, including cadence and step length, and (2) balance parameters, including time-to-contact and 95% ellipse area, using each patient as her own control. Laboratory assessment of gait and balance was conducted at baseline and at completion of therapy in selected patients. We compared the natural history of changes in gait and balance parameters with changes in CIPN status as measured by validated patient reported outcomes, including EORTC QLQ-C30, CIPN-20, and Brief Pain Inventory Short Form (BPI-SF), and the Duke Activity Status Index (DASI). Time points included pre-chemotherapy, after each cycle of chemotherapy, and one month after the end of therapy to collect information on neuropathy, pain and functional capacity. The preliminary data were illustrated using individual plots; trend lines (changing over time) were based on least square means at each time point, which were estimated using the linear mixed models for repeated measures. Results To date, 15 patients with localized breast cancer have been enrolled; patient recruitment is ongoing. The median age is 42 years (range 25-67). Ten patients (67%) received weekly paclitaxel, 1 patient (7%) received paclitaxel every 2 weeks, and 4 patients (27%) received docetaxel every 3 weeks. Preliminary results with these 15 patients, based on least square means at each timepoint, showed trends in several parameters. As treatments progressed, patients tended to develop more difficulty in quiet balance and in their ability to actively shift weight in the sagittal and frontal planes. From the CIPN-20, they also tended to develop increased difficulty with sensory and motor systems. From the QLQ-C30, their global health status also tended to worsen. For most of these parameters, the largest changes were observed between the 2nd and 3rd treatments, though some changes were not observed until the 4th treatment. From the BPI-SF, no trends in pain symptoms or pain interference were observed within this preliminary cohort. Conclusions Gait and balance testing is feasible in the clinical setting. Preliminary observations suggest that balance, function and quality of life may all be affected by taxane therapy, even without pain symptoms. The findings of this study will enable us to better characterize the neurotoxic effect of taxanes and to ultimately test the effectiveness of preventative measures and interventions. Funding by NCI R03CA182165-01. Citation Format: Maryam B Lustberg, Scott Monfort, Janani Singaravelu, Raquel E Reinbolt, Xueliang Pan, Bhuvaneswari Ramaswamy, Rachel M Layman, Robert Wesolowski, Ewa Mrozek, Erin Macrae, Charles Shapiro, Robyn Patrick, Charles L Loprinzi, Ajit Chaudhari. Longitudinal evaluation of taxane-induced neuropathy in early stage breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P1-09-04.