Jennifer M. Medina McKeon

Hip Strengthening Prior to Functional Exercises Reduces Pain Sooner Than Quadriceps Strengthening in Females With Patellofemoral Pain Syndrome: A Randomized Clinical Trial

STUDY DESIGN Randomized clinical trial. OBJECTIVES To determine if females with patellofemoral pain syndrome (PFPS) who perform hip strengthening prior to functional exercises demonstrate greater improvements than females who perform quadriceps strengthening prior to the same functional exercises. BACKGROUND Although PFPS has previously been attributed to quadriceps dysfunction, more recent research has linked this condition to impairment of the hip musculature. Lower extremity strengthening has been deemed an effective intervention. However, research has often examined weight-bearing exercises, making it unclear if increased strength in the hip, quadriceps, or both is beneficial. METHODS Thirty-three females with PFPS performed either initial hip strengthening (hip group) or initial quadriceps strengthening (quad group) for 4 weeks, prior to 4 weeks of a similar program of functional weight-bearing exercises. Self-reported pain, function, and functional strength were measured. Isometric strength was assessed for hip abductors, external rotators, and knee extensors. A mixed-model analysis of variance was used to determine group differences over time. RESULTS After 4 weeks, there was less mean ± SD pain in the hip group (2.4 ± 2.0) than in the quad group (4.1 ± 2.5) (P = .035). From baseline to 8 weeks, the hip group demonstrated a 21% increase (P<.001) in hip abductor strength, while that remained unchanged in the quad group. All participants demonstrated improved subjective function (P<.006), objective function (P<.001), and hip external rotator strength (P = .004) from baseline to testing at 8 weeks. CONCLUSION Both rehabilitation approaches improved function and reduced pain. For patients with PFPS, initial hip strengthening may allow an earlier dissipation of pain than exercises focused on the quadriceps.

Evaluation of the effectiveness of neuromuscular training to reduce anterior cruciate ligament injury in female athletes: a critical review of relative risk reduction and numbers-needed-to-treat analyses

Since previous numbers-needed-to-treat (NNT) and relative risk reduction (RRR) report, a few studies were published to evaluate prophylactic effectiveness of neuromuscular training for anterior cruciate ligament (ACL) injury in female athletes. The purpose of the current analyses was to determine the effectiveness of neuromuscular training interventions in reducing both non-contact and overall ACL injury risk in female athletes through RRR and NNT. The keywords ‘knee’, ‘anterior cruciate ligament’, ‘ACL’, ‘prospective’, ‘neuromuscular’, ‘training’, ‘female’ and ‘prevention’ were searched to find studies published from 1995 to 2011 in PubMed and EBSCO (CINAHL, Health source, MEDLINE and SPORT Discus). Inclusion criteria required that relevant studies: recruited physically active young girls as subjects, documented the number of ACL injuries, employed a neuromuscular training intervention, and used a prospective controlled study design. The numbers of non-contact and overall ACL injuries, subjects and observation time period were used to calculate RRR and NNT for each study. A total of 12 studies met the inclusion criteria. There was a 73.4% (95% CI 62.5% to 81.1%) and 43.8% (95% CI 28.9% to 55.5%) of RRR for non-contact and overall ACL injuries. From the NNT analysis, it was determined that, respectively, 108 (95% CI 86 to 150) and 120 (95% CI 74 to 316) individuals would need to be trained to prevent one non-contact or one overall ACL injury over the course of one competitive season. Although the RRR analysis indicated prophylactic benefits of neuromuscular training, the relatively large NNT indicated that many athletes are needed to prevent one ACL injury. A future direction to reduce NNT and improve the efficiency of ACL injury-prevention strategies is to develop a screening system for identifying at-risk athletes.

Compliance with neuromuscular training and anterior cruciate ligament injury risk reduction in female athletes: a meta-analysis.

CONTEXT No consensus exists about the influence of compliance with neuromuscular training programs on reduction of the risk of anterior cruciate ligament (ACL) injury. OBJECTIVE To systematically review and synthesize the published literature to determine if compliance with neuromuscular training is associated with reduced incidence of ACL injury in young female athletes. DATA SOURCES We searched PubMed, SPORTDiscus, CINAHL, and MEDLINE for articles published from 1995 to 2010 using the key words anterior cruciate ligament prevention, ACL prevention, knee prevention, prospective knee prevention, neuromuscular training, and neuromuscular intervention. STUDY SELECTION Criteria for inclusion required that (1) the number of ACL injuries was reported, (2) a neuromuscular training program was used, (3) females were included as participants, (4) the study design was prospective and controlled, and (5) compliance data for the neuromuscular training program were provided. DATA EXTRACTION Extracted data included the number of ACL injuries, total number of participants per group, observation time period, number of participants who completed each session, number of sessions completed by an entire team, and number of total sessions. Attendance was calculated as the number of participants who completed each session converted into a percentage of the total number of participants. Intervention completion was calculated as the number of sessions completed by an entire team converted into a percentage of the total number of training sessions. These data were used to calculate an overall rate of compliance. DATA SYNTHESIS Six of 205 identified studies were included. Incidence rates of ACL injury were lower in studies with high rates of compliance with neuromuscular training than in studies with low compliance rates (incidence rate ratio = 0.27 [95% confidence interval = 0.07, 0.80]). Tertile analysis indicated rates of ACL injury incidence were lower in studies with high compliance rates than in studies with moderate and low compliance rates (incidence rate ratio = 0.18 [95% confidence interval = 0.02, 0.77]). CONCLUSIONS A potential inverse dose-response relationship exists between compliance with neuromuscular training and incidence of ACL injury. Attending and completing recommended neuromuscular sessions appears to be an important factor for preventing ACL injuries.

Two-Week Joint Mobilization Intervention Improves Self-Reported Function, Range of Motion, and Dynamic Balance in Those with Chronic Ankle Instability

We examined the effect of a 2‐week anterior‐to‐posterior ankle joint mobilization intervention on weight‐bearing dorsiflexion range of motion (ROM), dynamic balance, and self‐reported function in subjects with chronic ankle instability (CAI). In this prospective cohort study, subjects received six Maitland Grade III anterior‐to‐posterior joint mobilization treatments over 2 weeks. Weight‐bearing dorsiflexion ROM, the anterior, posteromedial, and posterolateral reach directions of the Star Excursion Balance Test (SEBT), and self‐reported function on the Foot and Ankle Ability Measure (FAAM) were assessed 1 week before the intervention (baseline), prior to the first treatment (pre‐intervention), 24–48 h following the final treatment (post‐intervention), and 1 week later (1‐week follow‐up) in 12 adults (6 males and 6 females) with CAI. The results indicate that dorsiflexion ROM, reach distance in all directions of the SEBT, and the FAAM improved (p < 0.05 for all) in all measures following the intervention compared to those prior to the intervention. No differences were observed in any assessments between the baseline and pre‐intervention measures or between the post‐intervention and 1‐week follow‐up measures (p > 0.05). These results indicate that the joint mobilization intervention that targeted posterior talar glide was able to improve measures of function in adults with CAI for at least 1 week.

Return-to-play probabilities following new versus recurrent ankle sprains in high school athletes

OBJECTIVES Although ankle sprains have the highest recurrence rate of any musculoskeletal injury, objective estimates of when an athlete is likely to return-to-play (RTP) are unknown. The purpose was to compare time to return-to-play probability timelines for new and recurrent ankle sprains in interscholastic athletes. DESIGN Observational. METHODS Ankle sprain data were collected at seven high schools during the 2007-2008 and 2008-2009 academic years. Ankle sprains were categorized by time lost from participation (same day return, next-day return, 3-day return, 7-day return, 10-day return, >22-day return, no return [censored data]). Time-to-event analyses were used to determine the influence of ankle injury history on return-to-play after an ankle sprain. RESULTS 204 ankle sprains occurred during 479,668 athlete-exposures, 163 were new (4 censored) and 35 recurrent (1 censored). There was no significant difference (p=0.89) between the time-to-event curves for new and recurrent ankle sprains. The median (inter-quartile rage) time to return-to-play for new sprains (inter-quartile range)=3 days (same day to 7 day return); recurrent sprains=next day return (next day to 7 day return). Noteworthy probabilities [95% CIs] include: same day return (new=25.2[18.7, 31.9], recurrent=17.1[6.6, 30.3]); next-day return (new=43.6[35.3, 52.7], recurrent=51.4[32.5, 67.5]); and 7-day return (new=85.9[73.8, 94.4], recurrent=94.3[47.8, 99.5]). CONCLUSIONS Previous injury history did not affect time until return-to-play probabilities for ankle sprains. Time until return-to-play analyses that describe the likelihood of return-to-play are useful to clinicians by providing prognostic guidelines and can be used for educating athletes, coaches, and parents about the likely timeframe of being withheld from play.

Sex Differences and Representative Values for 6 Lower Extremity Alignment Measures

CONTEXT A discrepancy in anterior cruciate ligament (ACL) injury rates exists between men and women. Structural differences between the sexes often are implicated as a factor in this discrepancy. Researchers anecdotally assume that men and women tend to display different normative values for certain lower extremity alignments, but published information about these values is limited. OBJECTIVE To evaluate the effect of sex on 6 measures of lower extremity alignment and to report representative values of these measures from a sample of active adults and elite athletes. DESIGN Descriptive cohort design. SETTING University research laboratory. PATIENTS OR OTHER PARTICIPANTS A total of 118 healthy adults (57 men: age = 21.1 +/- 3.0 years, height = 179.1 +/- 7.3 cm, mass = 79.8 +/- 13.0 kg; 61 women: age = 20.0 +/- 1.6 years, height = 167.7 +/- 6.7 cm, mass = 62.7 +/- 5.5 kg) volunteered. MAIN OUTCOME MEASURE(S) Six common measures of lower extremity posture (navicular drop, tibial varum, quadriceps angle, genu recurvatum, anterior pelvic tilt, femoral anteversion) were collected using established methods. One measurement was taken for each participant for each lower extremity alignment. We measured the right lower extremity only. RESULTS Compared with men, women demonstrated larger quadriceps angles, more genu recurvatum, greater anterior pelvic tilt, and more femoral anteversion. CONCLUSIONS We observed differences between men and women for 4 of the 6 lower extremity alignments that we measured. Future researchers should focus on identifying how sex and skeletal alignment affect biomechanical performance of functional tasks and what these differences specifically mean regarding the discrepancy in anterior cruciate ligament injury rates between the sexes.

Evaluation of Joint Position Recognition Measurement Variables Associated With Chronic Ankle Instability: A Meta-Analysis

OBJECTIVE To identify the most precise and consistent variables using joint repositioning for identifying joint position recognition (JPR) deficits in individuals with chronic ankle instability (CAI). DATA SOURCES We conducted a computerized search of the relevant scientific literature from January 1, 1965, to July 31, 2010, using PubMed Central, CINAHL, MEDLINE, SPORTDiscus, and Web of Science. We also conducted hand searches of all retrieved studies to identify relevant citations. Included studies were written in English, involved human participants, and were published in peer-reviewed journals. STUDY SELECTION Studies were included in the analysis if the authors (1) had examined JPR deficits in patients with CAI using active or passive repositioning techniques, (2) had made comparisons with a group or contralateral limb without CAI, and (3) had provided means and standard deviations for the calculation of effect sizes. DATA EXTRACTION Studies were selected and coded independently and assessed for quality by the investigators. We evaluated 6 JPR variables: (1) study comparisons, (2) starting foot position, (3) repositioning method, (4) testing range of motion, (5) testing velocity, and (6) data-reduction method. The independent variable was group (CAI, control group or side without CAI). The dependent variable was errors committed during joint repositioning. Means and standard deviations for errors committed were extracted from each included study. DATA SYNTHESIS Effect sizes and 95% confidence intervals were calculated to make comparisons across studies. Separate meta-analyses were calculated to determine the most precise and consistent method within each variable. Between-groups comparisons that involved active repositioning starting from a neutral position and moving into plantar flexion or inversion at a rate of less than 5°/s as measured by the mean absolute error committed appeared to be the most sensitive and precise variables for detecting JPR deficits in people with CAI.

Trends in Concussion Return-to-Play Timelines Among High School Athletes From 2007 Through 2009

CONTEXT Whereas guidelines about return-to-play (RTP) after concussion have been published, actual prognoses remain elusive. OBJECTIVE To develop probability estimates for time until RTP after sport-related concussion. DESIGN Descriptive epidemiology study. SETTING High school. PATIENTS OR OTHER PARTICIPANTS Injured high school varsity, junior varsity, or freshman athletes who participated in 1 of 13 interscholastic sports at 7 area high schools during the 2007-2009 academic years. INTERVENTION(S) Athletic trainers employed at each school collected concussion data. The athletic trainer or physician on site determined the presence of a concussion. Athlete-exposures for practices and games also were captured. MAIN OUTCOME MEASURE(S) Documented concussions were categorized by time missed from participation using severity outcome intervals (same-day return, 1- to 2-day return, 3- to 6-day return, 7- to 9-day return, 10- to 21-day return, >21-day return, no return [censored data]). We calculated Kaplan-Meier time-to-event probabilities that included censored data to determine the probability of RTP at each of these time intervals. RESULTS A total of 81 new concussions were documented in 478 775 athlete-exposures during the study period. After a new concussion, the probability of RTP (95% confidence interval) was 2.5% (95% confidence interval = 0.3, 6.9) for a 1- to 2-day return, 71.3% (95% confidence interval = 59.0, 82.9) for a 7- to 9-day return, and 88.8% (95% confidence interval = 72.0, 97.2) for a 10- to 21-day return. CONCLUSIONS For high school athletes, RTP within the first 2 days after concussion was unlikely. After 1 week, the probability of return rose substantially (approximately 71%). Prognostic indicators are used to educate patients about the likely course of disease. Whereas individual symptoms and recovery times vary, prognostic time-to-event probabilities allow clinicians to provide coaches, parents, and athletes with a prediction of the likelihood of RTP within certain timeframes after a concussion.

Longitudinal Documentation of Serum Cartilage Oligomeric Matrix Protein and Patient-Reported Outcomes in Collegiate Soccer Athletes Over the Course of an Athletic Season

Background: Serum cartilage oligomeric matrix protein (sCOMP) is a biomarker for cartilage degradation. Patient-reported outcomes (PRO) are used to document postinjury recovery and may be used to prospectively identify changes in the course of a season. It is unknown what effect intense, continuous physical activity has on sCOMP levels and PRO values in athletes over the duration of a soccer season. Hypothesis/Purpose: The purpose of this study was to longitudinally document sCOMP levels and to determine whether changes in PROs occur in collegiate soccer athletes during a season. The hypotheses tested were that sCOMP levels and PRO scores would remain stable over the duration of the spring soccer season. Study Design: Case series; level of evidence, 4. Methods: Twenty-nine National Collegiate Athletic Association Division-I soccer athletes (18 men, 11 women; age, 19.6 ± 1.2 years; height, 177.8 ± 7.4 cm; mass, 73.8 ± 10.2 kg) participated in 3 (pre-[T1], mid-[T2], and postseason [T3]) data collection sessions. Subjects were included if they were participants in the spring soccer season and were free of severe knee injury at the time of data collection. At each session, subjects completed PROs (Lysholm, International Knee Documentation Committee scores) before serum collection. Results: For sCOMP (ng/mL), there was a significant effect for time, with significant increases at T2 (1723.5 ± 257.9, P < .001) and T3 (1624.7 ± 231.6, P = .002) when compared with T1(1482.9 ± 217.9). For each of the PROs, there was a significant effect for time from T1-T3, and at T2-T3 for the IKDC. Conclusion: These data indicate sCOMP levels increased as athletes reported an increased level of function over time. However, the differences in sCOMP levels did not reach the calculated minimal detectable change (MDC) value and the differences in PRO scores did not reach previously calculated MDC values. It is unclear whether these increases in sCOMP levels were caused by an increase in cartilage matrix breakdown or turnover. Even though these elevations may not be clinically meaningful, this biomarker may have the potential to be used for future research studies investigating the effects of exercise on overall joint health in longitudinal studies. In addition, these results indicate fluctuations in sCOMP occur during a competitive season and must be taken into consideration for future biomarker studies.

Comparing Responsiveness of Six Common Patient-Reported Outcomes to Changes Following Autologous Chondrocyte Implantation: A Systematic Review and Meta-Analysis of Prospective Studies.

Objective: To compare the responsiveness of six common patient-reported outcomes (PROs) following autologous chondrocyte implantation (ACI). Design: A systematic search was conducted to identify reports of PROs following ACI. Study quality was evaluated using the modified Coleman Methodology Score (mCMS). For each outcome score, pre- to postoperative paired Hedge’s g effect sizes were calculated with 95% confidence intervals (CIs). Random effects meta-analyses were performed to provide a summary response for each PRO at time points (TP) I (<1 year), II (1 year to <2 years), III (2 years to <4 years), IV (≥4 years), and overall. Results: The mean mCMS for the 42 articles included was 50.9 ± 9.2. For all evaluated instruments, none of the mean effect size CIs encompassed zero. The International Knee Documentation Committee Subjective Knee Form (IKDC) had increasing responsiveness over time with TP-IV, demonstrating greater mean effect size [confidence interval] (1.78 [1.33, 2.24]) than TP-I (0.88 [0.69, 1.07]). The Knee Injury and Osteoarthritis Outcome Score–Sports and recreation subscale (KOOS-Sports) was more responsive at TP-III (1.76 [0.87, 2.64]) and TP-IV (0.98 [0.81, 1.15]) than TP-I (0.61 [0.44, 0.78]). Overall, the Medical Outcomes Study 36-Item Short Form Health Survey Physical Component Scale (0.60 [0.46, 0.74]) was least responsive. Both the Lysholm Scale (1.42 [1.14, 1.72]) and the IKDC (1.37 [1.13, 1.62]) appear more responsive than the KOOS-Sports (0.90 [0.73, 1.07]). All other KOOS subscales had overall effect sizes ranging from 0.90 (0.74, 1.22) (Symptoms) to 1.15 (0.76, 1.54) (Quality of Life). Conclusions: All instruments were responsive to improvements in function following ACI. The Lysholm and IKDC were the most responsive instruments across time. IKDC and KOOS-Sports may be more responsive to long-term outcomes, especially among active individuals.