Search Results

You are looking at 1 - 9 of 9 items for

  • Author: Nelson Cortes x
Clear All Modify Search
Restricted access

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.

Restricted access

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.

Restricted access

Charles Bowles, Jatin P. Ambegaonkar, Nelson Cortes and Shane Caswell

Restricted access

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.

Restricted access

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.

Restricted access

Patricia M. Kelshaw, Trenton E. Gould, Mark Jesunathadas, Nelson Cortes, Amanda Caswell, Elizabeth D. Edwards and Shane V. Caswell

Girls’ lacrosse participation and head injury rates have increased within the past decade. In response, optional headgear was implemented following the recently developed ASTM International lacrosse headgear performance standards. It remains unknown how lacrosse headgear responds to blunt impacts after use. Our purpose was to compare the peak linear acceleration between girls’ lacrosse headgear conditions (pristine and used) during blunt impacts. Pristine headgear (n = 10) were tested in their original condition and used headgear (n = 10) were worn for an entire competitive season. A Cadex Monorail Impactor impacted all headgear following ASTM standards (F1446-15b, F2220-15, and F3137-15) in the required testing locations. A 2 × 7 repeated-measures analysis of variance compared peak linear acceleration among headgear conditions and impact locations with a simple effects analysis planned comparison. There was no difference between headgear conditions for peak linear acceleration (pristine: 47.12 [13.92] g; used: 46.62 [14.84] g; F = 2.11, P > .05). A main effect for impact location (F = 983.52, P < .01), and an interaction effect of condition and impact location (F = 12.79, P < .01) were observed. All headgear, regardless of condition, met the ASTM performance standard. This suggests that headgear performance may not degrade subsequent to a single season of high school girls’ lacrosse.

Restricted access

Patricia Kelshaw, Nelson Cortes, Amanda Caswell and Shane V. Caswell

A growing topic in research is that of cervical strength to potentially mitigate head impact kinematics (HIK) and concussion risk. The purpose of this research was two-fold: (a) Assess the effects of isometric cervical muscle strength (ICMS) on HIK in high school boys’ lacrosse, and (b) investigate the relationship between cervical anthropometrics and ICMS, to create greater feasibility to approximate ICMS. All participants wore accelerometers during the season, and had their ICMS measured. No significant differences existed among ICMS classifications and HIK measures (p > .05). Cervical circumference showed a positive, moderately strong relationship with ICMS in extension (r = .63, p = .02). Our findings do not support previous research that has identified ICMS as a modifiable risk factor for mitigating HIK.

Restricted access

Shane V. Caswell, Matthew York, Jatin P. Ambegaonkar, Amanda M. Caswell and Nelson Cortes

Restricted access

Ryan McCann, Nelson Cortes, Bonnie Van Lunen, Eric Greska, Stacie Ringleb and James Onate

Edited by Lindsey E. Eberman