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Nelson Cortes and James Onate

Context:

Clinical assessment tools are needed to identify individual athletes who possess elevated risk for anterior cruciate ligament injury. Existing methods require expensive equipment and the investment of a large amount of time for data processing, which makes them unfeasible for preparticipation screening of a large number of athletes.

Objective:

To assess the extent of agreement between LESS and the iLESS classifications of jump landing performance and the level of agreement between ratings assigned by a novice evaluator and an expert evaluator.

Methods:

Ratings of drop-jump landings from 20 video recordings of NCAA Division I collegiate athletes, which were randomly selected from a large database.

Results:

The dichotomous iLESS score corresponded to the dichotomous classification of LESS score for 15 of 20 cases rated by the expert evaluator and 17 of 20 cases rated by the novice evaluator. For the iLESS, only 2 scores out of 20 differed between the evaluators.

Conclusions:

A high level of agreement was observed between the LESS and iLESS methods for classification of jump- landing performance. Because the iLESS method is inexpensive and efficient, it may prove to be valuable for preparticipation assessment of knee injury risk.

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James Onate, Nelson Cortes, Cailee Welch and Bonnie Van Lunen

Context:

A clinical assessment tool that would allow for efficient large-group screening is needed to identify individuals potentially at risk for anterior cruciate ligament (ACL) injury.

Objective:

To assess the criterion validity of a jumplanding assessment tool compared with 3-dimensional (3D) motion analysis and evaluate interrater reliability across an expert vs novice rater using the Landing Error Scoring System (LESS).

Design:

Validity protocol.

Setting:

Controlled, laboratory.

Participants:

Nineteen female (age 19.58 ± .84 y, height 1.67 ± .05 m, mass 63.66 ± 10.11 kg) college soccer athletes volunteered.

Main Outcome Measurement:

Interrater reliability between expert rater (5 y LESS experience) vs novice rater (no LESS experience). LESS scores across 13 items and total score. 3D lower extremity kinematics were reduced to dichotomous values to match LESS items.

Interventions:

Participants performed drop-box landings from a 30-cm height with standard video-camera and 3D kinematic assessment.

Results:

Intrarater item reliability, assessed by kappa correlation, between novice and experienced LESS raters ranged from moderate to excellent (κ = .459–.875). Overall LESS score, assessed by intraclass correlation coefficient, was excellent (ICC2,1 = .835, P < .001). Statistically significant phi correlation (P < .05) was found between rater and 3D scores for knee-valgus range of motion; however, percent agreement between expert rater and 3D scores revealed excellent agreement (range of 84–100%) for ankle flexion at initial contact, knee-flexion range of motion, trunk flexion at maximum knee flexion, and foot position at initial contact for both external and internal rotation of tibia. Moderate agreement was found between rater and 3D scores for trunk flexion at initial contact, stance width less than shoulder width, knee valgus at initial contact, and knee-valgus range of motion.

Conclusions:

Our findings support moderate to excellent validity and excellent expert vs novice interrater reliability of the LESS to accurately assess 3D kinematic motion patterns. Future research should evaluate the efficacy of the LESS to assess individuals at risk for ACL injury.

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James A. Onate and Clay B. Marsh

Edited by John Parsons

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Roger O. Kollock, Bonnie Van Lunen, Stacie I. Ringleb and James Onate

The ability to produce force rapidly and to maintain it is essential to sports performance. Although rapid force production and endurance are indispensable characteristics of optimal health and performance, assessing these qualities of strength is difficult because of clinician time constraints. The purpose of this study was to determine if peak force is a predictor of rate of force production and strength endurance. The results indicated peak force is a predictor of rate of force development, but not strength endurance. Clinicians should assess both maximum strength and endurance to gain a more complete picture of lower extremity strength deficits.

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James A. Onate, Pranav Reddy and Anup Kanodia

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Katherine Lee, James Onate, Samar McCann, Tamerah Hunt, Wilbert Turner and Mark Merrick

Clinical Scenario:

In wrestling, athletes often support a large amount of weight on their heads or are forced into extreme ranges of motion. These suboptimal movement conditions lead to a high prevalence of neck injuries in wrestlers. A large portion of the work done by the cervical musculature in wrestling is theorized to be eccentric or isometric types of contractions. Strengthening of these cervical muscles is clinically considered to play a vital role in being competitive on the wrestling mat. The cervical stability provided by strengthening these muscles may also play a part in injury prevention among wrestlers.

Focused Clinical Question:

Does increased cervical strength lead to a decreased risk of injury in wrestling?

Summary of Search, “Best Evidence” Appraised, and Key Findings:

The literature was searched for studies of level 4 evidence or higher using the Oxford Centre for Evidence-Based Medicine level of evidence system that investigated the relationship between cervical strength and injury risk in wrestling. No studies were found comparing cervical strength to injury risk in wrestling, but 2 related studies were found and have been included in this critically appraised topic.

Clinical Bottom Line:

There is poor evidence to support a relationship between cervical strength and injury risk in wrestling.

Strength of Recommendation:

There is grade C evidence to indicate that increased cervical strength decreases the risk of injury in wrestling.

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Nelson Cortes, James Onate, João Abrantes, Linda Gagen, Elizabeth Dowling and Bonnie Van Lunen

The purpose of this study was to assess kinematic lower extremity motion patterns (hip flexion, knee flexion, knee valgus, and ankle dorsiflexion) during various foot-landing techniques (self-preferred, forefoot, and rear foot) between genders. 3-D kinematics were collected on 50 (25 male and 25 female) college-age recreational athletes selected from a sample of convenience. Separate repeated-measures ANOVAs were used to analyze each variable at three time instants (initial contact, peak vertical ground reaction force, and maximum knee flexion angle). There were no significant differences found between genders at the three instants for each variable. At initial contact, the forefoot technique (35.79° ± 11.78°) resulted in significantly (p = .001) less hip flexion than did the self-preferred (41.25° ± 12.89°) and rear foot (43.15° ± 11.77°) techniques. At peak vertical ground reaction force, the rear foot technique (26.77° ± 9.49°) presented significantly lower (p = .001) knee flexion angles as compared with forefoot (58.77° ± 20.00°) and self-preferred (54.21° ± 23.78°) techniques. A significant difference for knee valgus angles (p = .001) was also found between landing techniques at peak vertical ground reaction force. The self-preferred (4.12° ± 7.51°) and forefoot (4.97° ± 7.90°) techniques presented greater knee varus angles as compared with the rear foot technique (0.08° ± 6.52°). The rear foot technique created more ankle dorsiflexion and less knee flexion than did the other techniques. The lack of gender differences can mean that lower extremity injuries (e.g., ACL tears) may not be related solely to gender but may instead be associated with the landing technique used and, consequently, the way each individual absorbs jump-landing energy.

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Lacey Nordsiden, Bonnie L. Van Lunen, Martha L. Walker, Nelson Cortes, Maria Pasquale and James A. Onate

Context:

Many styles of foot pads are commonly applied to reduce immediate pain and pressure under the foot.

Objective:

To examine the effect of 3 different foot pads on peak plantar pressure (PPP) and mean plantar pressure (MPP) under the first metatarsophalangeal joint (MTPJ) during slow running.

Design:

A 4 (pad) × 4 (mask) repeated-measures design.

Setting:

University athletic training clinic and fitness facility.

Participants:

20 physically active participants, 12 men (19.7 ± 1.3 y, 181.5 ± 6.3 cm, 83.6 ± 12.3 kg) and 8 women (20.8 ± 1.5 y, 172.7 ± 11.2 cm, 69.9 ± 14.2 kg) with navicular drop greater than or equal to 10 mm, no history of surgery to the lower extremity, and no history of pain or injury to the first MTPJ in the past 6 months.

Interventions:

PPP and MPP were evaluated under 4 areas of the foot: the rear foot, lateral forefoot, medial forefoot, and first MTPJ. Four pad conditions (no pad, metatarsal dome, U-shaped pad, and donut-shaped pad) were evaluated during slow running. All measurements were taken on a standardized treadmill using the Pedar in-shoe pressure-measurement system.

Main Outcome Measures:

PPP and MPP in 4 designated foot masks during slow running.

Results:

The metatarsal dome produced significant decreases in MPP (163.07 ± 49.46) and PPP (228.73 ± 63.41) when compared with no pad (P < .001). The U-shaped pad significantly decreased MPP (168.68 ± 50.26) when compared with no pad (P < .001). The donut-shaped pad increased PPP compared with no pad (P < .001).

Conclusions:

The metatarsal dome was most effective in reducing both peak and mean plantar pressure. Other factors such as pad comfort, type of activity, and material availability must also be considered. Further research should be conducted on the applicability to other foot types and symptomatic subjects.

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Darin A. Padua, Michelle C. Boling, Lindsay J. DiStefano, James A. Onate, Anthony I. Beutler and Stephen W. Marshall

Context:

There is a need for reliable clinical assessment tools that can be used to identify individuals who may be at risk for injury. The Landing Error Scoring System (LESS) is a reliable and valid clinical assessment tool that was developed to identify individuals at risk for lower extremity injuries. One limitation of this tool is that it cannot be assessed in real time and requires the use of video cameras.

Objective:

To determine the interrater reliability of a real-time version of the LESS, the LESS-RT.

Design:

Reliability study.

Setting:

Controlled research laboratory.

Participants:

43 healthy volunteers (24 women, 19 men) between the ages of 18 and 23.

Intervention:

The LESS-RT evaluates 10 jump-landing characteristics that may predispose an individual to lower extremity injuries. Two sets of raters used the LESS-RT to evaluate participants as they performed 4 trials of a jump-landing task.

Main Outcome Measures:

Intraclass correlation coefficient (ICC2,1) values for the final composite score of the LESS-RT were calculated to assess interrater reliability of the LESS-RT.

Results:

Interrater reliability (ICC2,1) for the LESS-RT ranged from .72 to .81 with standard error of measurements ranging from .69 to .79.

Conclusions:

The LESS-RT is a quick, easy, and reliable clinical assessment tool that may be used by clinicians to identify individuals who may be at risk for lower extremity injuries.