The mechanics of moving along a curved path suggest that runners must change their body positions and thus adjust their lower extremity function as they accomplish a track turn. The purpose of the present study was to investigate the changes in the kinetics and kinematics of the lower extremity as runners proceed around the turn of a 400-m track (radius 31.5 m). Five skilled runners served as subjects in the study and were required to perform 10 trials in three conditions, running at 6.31 m/s plus or minus 5% (4:15 min/mile pace). The right and left limbs on a track turn and the right limb on the straightaway were evaluated using ground reaction force data and kinematic data from high-speed film. Statistical analysis of the 18 ground reaction force variables and 4 kinematic variables suggested that the right and left limbs at the midpoint of the track turn were asymmetrical and that most of the differences occurred in the first portion of the footfall Significant differences were found in the touchdown angle, maximum pronation angle, all mediolateral variables, and in the vertical variables describing the collision phase of the footfall (p < .05). The data suggest that the etiologies of injuries to the right and left lower extremity differ, with right foot injuries being of the impact type and left leg injuries being of the overpronation type.
Joseph Hamill, Michael Murphy and Donald Sussman
Gemma V. Espí-López, Pilar Serra-Añó, David Cobo-Pascual, Manuel Zarzoso, Luis Suso-Martí, Ferran Cuenca-Martínez and Marta Inglés
Context: Knee injury prevention is a critical aspect in sport rehabilitation sciences, and taping is a widely used technique in this field. Nevertheless, the role and effectiveness of a long-term application of Kinesio Taping (KT) on knee function, disability, and injury prevention remain unclear. Objective: To determine the effect of KT, alone or in combination with balance exercises (BE), on dynamic and static knee balance and flexibility. Design: Randomized trial design. Setting: University of Valencia (Spain). Participants: Forty-eight male amateur soccer players. Intervention: Participants were assigned to 3 groups: Sham KT (sKT) + BE, KT + BE, and KT in isolation. The intervention period lasted 4 weeks. Three evaluations were performed: at baseline (pre), at 2 weeks (mid), and at 4 weeks posttreatment (post). Main outcome measures: Y Balance Test, unipedal stance test, the toe touch test, and the Knee Injury and Osteoarthritis Outcome Score. Results: Both sKT + BE and KT + BE groups achieved significant pre–post improvements in SEBT, unipedal stance test, and toe touch test. The KT group only showed significant intragroup differences in the left and right unipedal stance test variable (P < .05, d = 0.76, d = 0.62, respectively). The sham KT group obtained the strongest results in all physical variables. Regarding the Knee Injury and Osteoarthritis Outcome Score, pre–post significant changes were found in the sham group (P < .05, d = 0.28). Conclusions: Both sham and real KT in combination with BE achieved significant improvements on all physical variables, and these differences were significantly greater compared with those found in the KT in the isolation group, suggesting that benefits in knee function are due to the BE. Level of Evidence: Therapy level 1b.
Mark G. Davis, Kenneth R. Fox, Afroditi Stathi, Tanya Trayers, Janice L. Thompson and Ashley R. Cooper
The relationship of objectively measured sedentary time (ST), frequency of breaks in ST, and lower extremity function (LEF) was investigated in a diverse sample aged ≥ 70 years (n = 217). Physical activity (PA) was assessed by accelerometry deriving moderate-vigorous PA (MVPA) minutes per registered hour (MVPA min · hr−1), registered ST (ST min · hr−1), and breaks in ST min · hr−1 (breaks · hr−1). LEF was assessed by the Short Physical Performance Battery. Univariate associations with overall LEF were MVPA (r = .523), ST (r = −.499), and breaks (r = .389). Adjusted linear regression including MVPA min · hr−1, ST min · hr−1, and breaks · hr−1 explained 41.5% of LEF variance. Each additional break · hr−1 was associated with 0.58 point increase in LEF. Breaks and MVPA had strongest independent associations with LEF. Promoting regular breaks might be useful in maintaining or increasing LEF and later life independence. This novel finding is important for the design of effective lifestyle interventions targeting older adults.
Shani Batcir and Itshak Melzer
functional scores of LLFDI (overall function, upper-extremity function, and basic and advanced lower-extremity functions). A significance level of 0.05 was used. Results There were no significant differences in age, gender, height, weight, number of falls, and medications per day, as well as upper
Janet S. Dufek, John A. Mercer and Janet R. Griffin
The purpose of the study was to examine the effects of running speed and surface compliance on shock attenuation (SA) characteristics for male and female runners. We were also interested in identifying possible kinematic explanations, specifically, kinematics of the lower extremity at foot-ground contact, for anticipated gender differences in SA. Fourteen volunteer recreational runners (7 male, 7 female) ran at preferred and slow speeds on an adjustable bed treadmill, which simulated soft, medium, and hard surface conditions. Selected kinematic descriptors of lower extremity kinematics as well as leg and head peak impact acceleration values were obtained for 10 left leg contacts per subject-condition. Results identified significant SA values between genders across conditions and more specifically, across surfaces for females, with male runners demonstrating a similar trend. Regression modeling to predict SA by gender for surface conditions elicited unremarkable results, ranging from 30.9 to 59.9% explained variance. It appears that surface compliance does affect SA during running; however, the runner’s ability to dissipate the shock wave may not be expressly explained by our definition of lower extremity kinematics at contact.
Janice Kaye Loudon, Byron Gajewski, Heather L. Goist-Foley and Karen Lee Loudon
To determine the effect of exercise on patients with patellofemoral-pain syndrome (PFPS).
29 subjects with unilateral PFPS, assigned to control, home-exercise (HE), or physical therapy (PT) group.
8-wk exercise program.
Main Outcome Measures:
A knee survey, visual analog scale (VAS), and 5 weight-bearing tests.
MANOVA indicated an overall statistical difference between groups (P < .05). The HE and PT groups experienced less pain than control, and PT experienced less pain than HE (P < .05). In overall knee function and most weight-bearing tests, HE and PT were stronger and more functional than control (P < .05). For anteromedial lunge only PT was stronger and more functional than control (P < .05).
Intervention helps PFPS, but there appear to be no differences between home and in-clinic interventions.
Lori A. Bolgla and Douglas R. Keskula
To provide information on research investigating the relationship between a knee effusion and quadriceps inhibition
Peer-reviewed publications from 1965 to 1997 that investigated the effect of a knee effusion on quadriceps strength.
The studies reviewed involved human subjects. Researchers have used active motion, electromyographic equipment, and isokinetics to measure changes in quadriceps strength after a knee effusion.
Most studies reported that a knee effusion resulted in quadriceps inhibition and inferred that quadriceps inhibition would impair knee function.
The authors believe that additional research is needed to better understand the effect of a knee effusion on knee function. Although a knee effusion might lead to quadriceps inhibition, other factors contribute to normal knee function and might allow enough compensation so that knee function is not affected significantly in the presence of certain effusions.
Jane Chung, George Demiris and Hilaire J. Thompson
Mobility is critical in maintaining independence in older adults. This study aims to systematically review the scientific literature to identify measures of mobility limitation for community-dwelling older adults. A systematic search of PubMed, CINAHL, and psycINFO, using the search terms “mobility limitation”, “mobility disability”, and “mobility difficulty” yielded 1,847 articles from 1990 to 2012; a final selection of 103 articles was used for the present manuscript. Tools to measure mobility were found to be either self-report or performance-based instruments. Commonly measured constructs of mobility included walking, climbing stairs, and lower extremity function. There was heterogeneity in ways of defining and measuring mobility limitation in older adults living in the community. Given the lack of consistency in assessment tools for mobility, a clear understanding and standardization of instruments are required for comparison across studies and for better understanding indicators and outcomes of mobility limitation in community-dwelling older adults.
Matthew T. Crill, Christopher P. Kolba and Gary S. Chleboun
The lunge is commonly used to assess lower extremity strength, flexibility, and balance, yet few objective data exist on it.
To determine the reliability of the lunge test, determine whether there are gender differences associated with it, and study the relationships between lunge distance and height and leg length.
Single-factor repeated measures.
57: 29 men, 28 women.
Main Outcome Measures:
Anterior lunge (AL) and lateral lunge (LL) distance, height, and leg length (cm).
LL distance (131.3 ± 12.3) is significantly greater than AL distance (113.7 ± 17.2) in men and in women (LL 113.6 ± 10.5, AL 96.6 ± 11.1). There was no significant correlation for height or leg length to any lunge measurement in men or women.
The lunge can be used as a reliable test to measure lower extremity function. Right- and left-leg lunge distances should not differ, and LL will always be greater than AL.
Joseph M. Hart, Jamie L. Leonard and Christopher D. Ingersoll
Despite recent findings regarding lower extremity function after cryotherapy, little is known of the neuromuscular, kinetic, and kinematic changes that might occur during functional tasks.
To evaluate changes in ground-reaction forces, muscle activity, and knee-joint flexion during single-leg landings after 20-minute knee-joint cryotherapy.
1 × 4 repeated-measures, time-series design.
Patients or Other Participants:
20 healthy male and female subjects.
Subjects performed 5 single-leg landings before, immediately after, and 15 and 30 minutes after knee-joint cryo-therapy.
Main Outcome Measures:
Ground-reaction force, knee-joint flexion, and muscle activity of the gastrocnemius, hamstrings, quadriceps, and gluteus medius.
Cryotherapy did not significantly (P > .05) change maximum knee-joint flexion, vertical ground-reaction force, or average muscle activity during a single-leg landing.
Knee-joint cryotherapy might not place the lower extremity at risk for injury during landing.