Athletic Training and Sports Health Care

Original Research 

Traditional Helmet Hardware Is More Likely to Fail Following Use, Compared With Quick-release Designs

Julianne D. Schmidt, MA, ATC; Steven M. Zinder, PhD, ATC; Meredith A. Petschauer, PhD, ATC; Kevin M. Guskiewicz, PhD, ATC

Abstract

Helmet designs using quick-release mechanisms reduce the time taken to access the airway, compared with traditional helmet designs. Little is known about how use during a season of play influences the integrity of the quick-release mechanism. Football face masks (52 quick-release, 35 traditional) were removed following use during the fall and spring football seasons. Three 2-tailed chi-squared analyses were conducted to assess the association between helmet design and face mask removal failures, lateral hardware failures, and superior hardware failures. A significant association was observed between helmet design and lateral hardware failure. Traditional helmet hardware was 7.05 times more likely to fail at one or more lateral strap locations compared with the quick-release design. No significant association was found between helmet design and overall face mask removal failure. These findings suggest that the quick-release design is more efficient for managing airway access, even after use for a fall and spring seasons.

Abstract

Helmet designs using quick-release mechanisms reduce the time taken to access the airway, compared with traditional helmet designs. Little is known about how use during a season of play influences the integrity of the quick-release mechanism. Football face masks (52 quick-release, 35 traditional) were removed following use during the fall and spring football seasons. Three 2-tailed chi-squared analyses were conducted to assess the association between helmet design and face mask removal failures, lateral hardware failures, and superior hardware failures. A significant association was observed between helmet design and lateral hardware failure. Traditional helmet hardware was 7.05 times more likely to fail at one or more lateral strap locations compared with the quick-release design. No significant association was found between helmet design and overall face mask removal failure. These findings suggest that the quick-release design is more efficient for managing airway access, even after use for a fall and spring seasons.

The authors are from The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.

The authors have no financial or proprietary interest in the materials presented herein.

The authors thank Dr. Erik Swartz for use of the mounting fixture during data collection.

Address correspondence to Julianne D. Schmidt, MA, ATC, Department of Exercise and Sport Science, The University of North Carolina at Chapel Hill, 209 Fetzer Hall, CB#8700, NC 27599-8700; e-mail: jtoler@email.unc.edu.

Received: January 25, 2011
Accepted: June 14, 2011
Posted Online: August 17, 2011

Medical professionals working in the football setting are faced with the challenging task of managing suspected cervical spine injuries on the field. Protective equipment used in sports such as football, lacrosse, and ice hockey acts as a barrier to airway access. When treating an athlete with a suspected cervical spine injury, clinicians aim to limit the amount of head movement that may occur while simultaneously reducing the amount of time taken to access the airway. Current recommendations for removing the face mask on the field dictate that medical professionals use a cord-less screwdriver with a backup cutting tool in case of hardware failure.1–3 Cutting through the loop strap has been observed to result in greater helmet movement and takes longer.4–6 If the face mask cannot be removed in an acceptable period of time, the medical professional must remove the helmet entirely.1,7 This approach could be time costly, place the cervical spine in an extended position (limiting intrathecal space), and cause encroachment on the spinal cord by the fragmented vertebrae.8–11

Recently, helmet manufacturers have designed helmets with the goal of allowing rapid access to the airway. Revolution IQ and Speed helmets (Riddell Inc, Elyria, Ohio) use a quick-release mechanism in place of the traditional T-bolts and T-nuts adjacent to the ears. A specially designed tool is inserted into a central button to release the pin that secures the connector on the inside of the helmet’s shell (Figure 1A). The quick-release mechanism is installed in place of the traditional T-bolts and T-nuts adjacent to the ears, allowing for quick removal of the lateral straps and rapid access to the airway.1,12 The superior loop straps are secured with traditional T-bolts and T-nuts identical to traditional helmets. Recent studies have observed that this new quick-release design reduced the time it took to access the airway of an equipped football model compared with traditional helmet designs on which a cordless screwdriver was used to remove the T-bolts.1,12

(A) Specially designed tool designed to release the quick-release mechanism. (B) Orienting the Phillip’s head perpendicular with the T-bolt head while operating in reverse mode.

Figure 1. (A) Specially designed tool designed to release the quick-release mechanism. (B) Orienting the Phillip’s head perpendicular with the T-bolt head while operating in reverse mode.

Previous research suggests that helmet hardware may be more difficult to remove after a season of play due to exposure to impacts, weather, and turf conditions.13,14 In addition, the lateral strap locations have been reported to have a higher hardware failure rate compared with the superior strap.6,13,14 Because the quick-release helmet design is relatively new, little is known about how exposure from use throughout the fall and spring seasons influences its integrity. It is currently unknown how the intricate design of the quick-release mechanism will respond to exposure during a season of play.

Failure of the quick-release design would require medical staff to use a secondary cutting tool to remove the face mask, which may cause more head movement and take additional time,4,6 increasing the potential for secondary spinal cord injury. The purpose of this investigation was to study the association between helmet designs (traditional or quick-release) and face mask removal failure, lateral hardware failure, and superior hardware failure in helmets worn during a fall and spring seasons of play.

Method

Eighty-seven helmets were sampled from a total of 118 helmets used by a Football Bowl Subdivision collegiate team. This subpopulation of helmets was chosen because they were all designed by the same manufacturer. The lateral straps of 52 helmets were equipped with the quick-release mechanism and 35 helmets were equipped with traditional T-bolts and T-nuts. The superior loop straps of all helmets were secured with T-bolts and T-nuts. All helmets were obtained by the research team immediately following the completion of the spring season before being sent off for refurbishment. No changes were made to the helmets from the time the players returned them to the equipment management team to when the researchers began data collection.

Procedures

Each helmet was secured to a customized helmet mount fixture prior to face mask removal (Figure 2).13 The posterior portion of the helmet rested within the retractable stabilizers covered with a turf surface in an attempt to represent on-field conditions. Tie-down straps, secured to the board, were attached by hooks through the ear holes of the helmet to simulate manual inline stabilization of the cervical spine. Shoulder pads covered with a jersey were approximated with the mount to simulate interference of other equipment during face mask removal. Two athletic trainers, currently working in a football setting, removed the face masks (athletic trainer 1: quick-release = 24 face masks, traditional = 8 face masks; athletic trainer 2: quick-release = 28 face masks, traditional = 27 face masks). Helmet designs were alternated for both athletic trainers until all traditional helmet face masks had been removed. The athletic trainer then proceeded with the remaining quick-release design helmets.

Mounting fixture used to secure helmets prior to face mask removal.

Figure 2. Mounting fixture used to secure helmets prior to face mask removal.

All face masks were removed over a 3-day period, for a total of 7 hours of face mask removal, with no single session lasting longer than 2.5 hours. Both athletic trainers were instructed on technique by a brief video demonstration and verbal instruction from the investigator. The athletic trainers were instructed to complete the technique in the least amount of time while creating as minimal helmet movement as possible and were given a practice period prior to data collection. To prevent bias, the athletic trainers were not informed of the investigators’ hypotheses. Between each face mask removal, athletic trainers rated their perceived exertion and waited while the principal investigator (J.D.S.) affixed the next helmet to the customized helmet mount. After each face mask removal, the athletic trainers were instructed to take as much time as needed before starting the next face mask removal to allow for adequate recovery.

For face mask removal of quick-release helmets, the athletic trainers were instructed to release the quick-release mechanism that secures the lateral straps by inserting a specially designed tool into the indentation of the quick-release mechanism (Figure 1A). Instruction then detailed that the superior loop straps had to be removed with the cordless screwdriver by orienting the Phillip’s head perpendicular with the T-bolt head while operating in reverse mode (Figure 1B). For traditional helmets, instructions were similar to the quick-release design, with T-bolt removal of both the lateral and superior straps. In cases of hardware failure, the athletic trainers were instructed to proceed with the cutting tool to incise the loop strap using an FMxtractor (Sports Medicine Concepts Inc, Livonia, New York). The athletic trainers were then trained to remove the face mask by pulling it upward away from the helmet with both hands.

Prior to face mask removal of quick-release helmets, the athletic trainers were given a cordless screwdriver, a back-up cutting tool, and the specially designed tool. Prior to face mask removal of traditional helmets, the athletic trainer was given a cordless screwdriver and a back-up cutting tool.

Time to face mask removal and rating of perceived exertion were recorded by the principal investigator following each trial.

Instrumentation

Athletic trainers used a Ryobi 4V Lithium-ion cordless screwdriver (Model#HP41LK; Ryobi Technologies Inc, Anderson, South Carolina) for all trials. The primary investigator used a standard stopwatch to record time to face mask removal. A rating of perceived exertion was obtained following each trial using the Borg category-ratio CR10 scale (Table 1). After each trial, the athletic trainer was asked to rate their perception of difficulty using the Borg CR10 scale. This scale ranges from 0 (nothing at all) to 10 (impossible) and has been shown to be a reliable and valid scale for quantifying difficulty.15 This scale has also been used in previous related studies.1,2,6

Borg CR10 Ratings of Perceived Exertion Scale

Table 1: Borg CR10 Ratings of Perceived Exertion Scale

Data Analysis

Face mask removal failure was considered when the athletic trainer was unable to remove the face mask in less than 3 minutes.1,6,13 A hardware failure was recorded for the lateral and superior hardware whenever the athletic trainer was unable to remove the T-bolt and a cutting tool was required to release the loop strap from the helmet. To investigate the quick-release mechanism independent of the traditional T-bolt, hardware failure was recorded for hardware at each of the 4 locations on the helmet. Hardware failures were then collapsed into 2 categories: did not fail (successful T-bolt removal) or failure of at least one (required cutting tool). Time to face mask removal was recorded in seconds from the point when the athletic trainer made first contact between the tool and the helmet to the point when the face mask was placed on the ground. All data were handwritten onto a data collection spreadsheet and manually entered into SPSS version 19 (SPSS Inc, Chicago, Illinois) software for statistical analysis. Someone independent of the research team verified data entry accuracy by determining that values handwritten on the data collection sheet matched those entered into the SPSS software.

Statistical Analysis

Three 2-tailed chi-squared analyses were conducted to assess the association between helmet design (quick-release verus traditional) and face mask removal failure (unable to remove face mask versus face mask removed), lateral hardware failure (hardware failure at one or both locations versus no hardware failure), and superior hardware failure (hardware failure at one or both locations versus no hardware failure). Analysis of face mask removal failures revealed that a Fisher’s exact test was necessary to account for low cell counts. An analysis of covariance (ANCOVA) was used to assess differences in time to face mask removal between quick-release and traditional helmet designs while accounting for rating of perceived exertion. Four trials were not included in the ANCOVA because these trials were stopped after the face mask was not removed within 3 minutes, constituting full removal of the helmet. Significance was set at an a priori alpha level of P ⩽ .05 for all analyses.

Results

Descriptive and statistical results for face mask and hardware failure are presented in Table 2. No significant association was observed between helmet design and overall face mask removal failure (P = .298), suggesting that overall face mask removal success is similar between quick-release and traditional helmets. However, a significant association was observed between helmet design and lateral hardware failure (χ2 = 13.06, P < .001). Traditional helmet hardware was 7.05 times more likely to fail at one or both lateral strap locations compared with the quick-release design. No association was observed between helmet design and superior hardware failure (χ2 = 0.63, P = .454).

Frequency and Percentage of Failures and Successes Within Helmet Design

Table 2: Frequency and Percentage of Failures and Successes Within Helmet Design

Traditional and quick-release helmet designs had similar odds of superior hardware failure. Face masks on the quick-release helmets were removed significantly faster (47.1±23.6 sec; 95% confidence interval [CI]: 40.5, 53.8) compared with traditional designs (72.3±40.0 sec; 95% CI: 57.9, 86.7) (F1,81 = 6.33, P = .014, cohen’s d = 0.81) when controlling for ratings of perceived exertion. Ratings of perceived exertion were rated significantly higher for face mask removal of traditional helmets (3.71±1.84 points; 95% CI: 2.4, 3.0) compared with the quick-release design (2.70±1.19 points; 95% CI: 3.1, 4.3) (F1,85 = 9.705, P = .003, Cohen’s d = 0.68). Following the primary analyses of helmet design comparisons, we used a correlational analysis between the helmet testing order and time to face mask removal to determine whether the practice or fatigue involved with removing several face masks consecutively may have influenced time. No relationship existed between the order in which helmets were tested and time taken to remove the face mask (r = −0.096, P = .389).

Discussion

Because protective equipment acts as a barrier to airway access and is subject to extraneous variables such as weather, turf conditions, and impacts, it is crucial that medical professionals seek out the equipment that provides the least hindrance to removal. The most important findings of this study were that the traditional helmet hardware was 7.05 times more likely to fail at the lateral loop strap and took significantly longer to remove compared with the quick-release design.

Face Mask Removal Failure

Of the 87 helmets tested, only 4 face masks could not be removed in the allotted 3 minutes. Of these 4 face mask removal failures, 3 were traditional helmets and 1 was a quick-release helmet. All 4 face mask removal failures that occurred presented with at least 1 hardware failure at the superior loop strap location, whereas only 2 helmets (1 traditional and 1 quick-release) presented with a hardware failure at the lateral strap location. However, no association was observed between helmet design and overall face mask removal failure, suggesting that differences in helmet design do not influence whether the face mask can be removed on the field. A larger helmet sample may be necessary to capture enough face mask removal failures to assess the association between helmet designs. However, we observed that the face masks of the quick-release helmets were removed more quickly than traditional helmets. This is likely attributable to the differences in hardware failures.

Hardware Failure

Helmets equipped with the quick-release mechanism allowed for more rapid face mask removal with fewer lateral hardware failures. A hardware failure does not mean that the face mask could not be removed, but rather that the alternate cutting tool was required to remove the plastic strap encasing the helmet hardware. Hardware securing the lateral strap on the traditional helmets was 7.05 times more likely to fail at one or more lateral strap locations compared with the quick-release mechanisms (Table 2). Of the 35 traditional helmets that were studied, 42.9% resulted in hardware failure at one or both lateral strap locations. These results indicate that nearly half of traditional hardware may fail following exposure during the fall and spring seasons of play. These findings suggest that the new quick-release design, with just less than 10% resulting in hardware failure at one or both lateral strap locations, is more efficient for managing airway access in football even after use for a fall and spring seasons of play. Sports medicine professionals and equipment managers responsible for football equipment safety should consider endorsing the use of helmets that use a quick-release mechanism.

No association was observed between helmet design and superior hardware failure. These findings were expected because both the quick-release and traditional helmets use the same hardware (T-bolts and T-nuts) to secure the superior face mask. Traditional hardware at the superior strap location had higher percentage failures (quick-release = 21.2%; traditional = 28.6%) than the helmets equipped with the quick-release mechanism at the lateral strap (9.6%). These results support our previously discussed findings that the quick-release design reduces the odds of requiring a secondary cutting tool to remove the face mask. On the basis of these results, helmet manufacturers should consider expanding use of the quick-release mechanism at the superior location.

Recently, Riddell released its latest helmet design, the Riddell 360, which incorporates additional quick-release mechanisms in place of the superior T-bolts and T-nuts. However, the quick-release mechanisms are located more laterally than in previous helmet designs. Additional research is necessary to determine how this new design influences face mask removal. Medical staff responsible for the care of athletes on the field should be familiar with equipment used by their teams and always be prepared with a back-up cutting tool because hardware failure is possible with all designs.3

Time to Face Mask Removal

Although helmet design was not associated with overall face mask removal failure, time to access the airway was an average of 25 seconds faster for the quick-release helmets. In an on-field scenario, this could mean that an additional 5 cycles of rescue breathing could be completed. These findings support our previously published study, in which we observed the quick-release design allowed time for an additional 3 to 4 cycles of rescue breathing compared with traditional helmets.12 Exposure to impact forces, weather, and turf conditions could have more of an influence on the time to face mask removal for traditional helmets. In an athlete with a compromised airway, excess time taken to access the airway could mean secondary cell death due to hypoxia.

Our findings are consistent with those observed by Swartz et al,1 which simulated failure by purposefully altering helmet hardware. In helmets that had not been altered, quicker airway access was gained when removing the face mask of the Revolution IQ helmet, which uses the quick-release mechanism, compared with traditional designs. However, when the quick-release helmets were adapted to result in hardware failure and athletic trainers were forced to use a secondary cutting tool, removal became more time costly and difficult.1 In the face of quick-release mechanism failure, the bolt is incased with a thicker plastic straps, which can often be more difficult to cut through.

Ratings of Perceived Exertion

We observed significantly higher ratings of perceived exertion for face mask removal of traditional helmets compared with the quick-release design, indicating that athletic trainers felt that removing the face mask from traditional helmets was slightly more difficult. However, differences between mean ratings of perceived exertion represent only a 1-point change on the Borg CR10. On average, face mask removal of traditional helmets was rated just less than a 4, indicating that the task was somewhat hard. Removal of the face mask of traditional helmets was rated just less than a 3, indicating that the task was of moderate difficulty. Although differences were observed, the true difference between means may not indicate a clinically meaningful difference in task difficulty between traditional and quick-release helmets.

Limitations

This study is not without limitations. Throughout the season, helmets are exposed to different impact forces and weather conditions. We were not able to control for or record exposure. In addition, standard equipment maintenance occurred throughout the fall and spring seasons and may influence the occurrences of failure in some helmets. However, this study provides a unique look at helmet condition following a season of play regardless of extraneous variables. This cross-sectional time point offers a worst-case scenario of hardware failure and face mask removal failure.

This study did not use a live football model during face mask removal trials because head and helmet movements were not being measured. Most previous studies have either used a stabilized helmet or a healthy model to determine parameters of face mask removal success, such as time to airway access or helmet movement.1–6,12–14,16–20 Helmets stabilized by a mount may not accurately represent the level of stabilization provided by a clinician on the field during an emergency situation. Further research may be necessary to determine how exposure during a season of play influences head movement associated with removing the face mask. To best estimate how the injured cervical spine responds to face mask removal techniques, future research should incorporate the use of destabilized cadaveric models.

Helmet designs were alternated until no traditional helmets remained in tact. The face masks of the remaining quick-release helmets were then removed consecutively. It is possible that the athletic trainers gained more experience as they progressed through face mask removals, potentially reducing the time and ratings of perceived exertion for the later helmets. However, we observed no relationship between the order in which helmets were tested and the time taken to remove the face mask.

Athletic trainer 2 removed more face masks from traditional helmets than did athletic trainer 1. This difference resulted because as we alternated helmet designs and eventually ran out of traditional helmets, athletic trainer 1 was left to remove the remaining quick-release helmets rather than alternating between designs. Although there are no evident signs that the 2 athletic trainers were different in their skill or proficiency with one helmet design over another, it is important to consider that differences between athletic trainers could have influenced the removal success between the helmet designs. Future research designs should control for the number of helmet types tested by each athletic trainer.

Helmets equipped with a quick-release mechanism allowed for more rapid face mask removal while simultaneously resulting in fewer hardware failures for lateral straps. Further efforts should be made to improve the plastic strap encasing the quick-release mechanism to avoid complications in the rare case that it does fail. Clinicians should consider promoting the use of football equipment designs that incorporate the quick-release mechanism. Manufacturers may consider expanding the use of the quick-release mechanism to other equipment-intensive sports.

Implications for Clinical Practice

Equipment managers and athletic trainers should consider the findings of our study as they pertain to both helmet hardware maintenance and medical protocols for managing potentially catastrophic injuries on the football field. Helmet manufacturers should consider expanding use of the quick-release mechanism to the superior location and improving the lateral strap to allow for quicker access with a cutting tool in case of hardware failure. A common effort should be made by coaches, parents, equipment managers, athletic trainers, and team physicians to provide athletes with the best equipment possible for managing cervical spine injuries on the field.

References

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  2. Copeland AJ, Decoster LC, Swartz EE, Gattie ER, Gale SD. Combined tool approach is 100% successful for emergency football face mask removal. Clin J Sport Med. 2007;17(6):452–457. doi:10.1097/JSM.0b013e31815b187d [CrossRef]
  3. Gale SD, Decoster LC, Swartz EE. The combined tool approach for face mask removal during on-field conditions. J Athl Train. 2008;43(1):14–20. doi:10.4085/1062-6050-43.1.14 [CrossRef]
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  6. Swartz EE, Norkus SA, Cappaert T, Decoster LC. Football equipment design affects face mask removal efficiency. Am J Sports Med. 2005;33(8):1210–1219. doi:10.1177/0363546504271753 [CrossRef]
  7. Swartz EE, Boden BP, Courson R, et al. National Athletic Trainers’ Association position statement: acute management of the cervical spine-injured athlete. J Athl Train. 2009;44(3):306–331. doi:10.4085/1062-6050-44.3.306 [CrossRef]
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  10. Prinsen RK, Syrotuik DG, Reid DC. Position of the cervical vertebrae during helmet removal and cervical collar application in football and hockey. Clin J Sport Med. 1995;5(3):155–161. doi:10.1097/00042752-199507000-00004 [CrossRef]
  11. Tierney RT, Mattacola CG, Sitler MR, Maldjian C. Head position and football equipment influence cervical spinal-cord space during immobilization. J Athl Train. 2002;37(2):185–189.
  12. Toler JD, Petschauer M, Mihalik JP, Oyama S, Halverson SD, Guskiewicz KM. Comparison of 3 airway access techniques during suspected spine injury management in American football. Clin J Sport Med. 2010;20(2):92–97. doi:10.1097/JSM.0b013e3181d2de5f [CrossRef]
  13. Swartz EE, Decoster LC, Norkus SA, Cappaert TA. The influence of various factors on high school football helmet face mask removal: a retrospective, cross-sectional analysis. J Athl Train. 2007;42(1):11–20.
  14. Decoster LC, Shirley CP, Swartz EE. Football face-mask removal with a cordless screwdriver on helmets used for at least one season of play. J Athl Train. 2005;40(3):169–173.
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  17. Petschauer MA. Effectiveness of Cervical Spine Stabilization During Spine Boarding of Collegiate Lacrosse Athletes [dissertation]. Greensboro: University of North Carolina; 2006.
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Borg CR10 Ratings of Perceived Exertion Scale

RATINGDEFINITION
0Nothing at all
0.5Very, very easy
1Very easy
2Easy
3Moderate
4Somewhat hard
5Hard
6
7Very hard
8
9Very, very hard
10Impossible

Frequency and Percentage of Failures and Successes Within Helmet Design

OUTCOME MEASURESQUICK-RELEASE (n = 52)
TRADITIONAL (n = 35)
ODDS RATIOP
FAILUREaSUCCESSFAILUREaSUCCESS
Face mask removal1 (1.9%)51 (98.1%)3 (8.6%)32 (91.4%)b.298
Lateral hardware5 (9.6%)47 (90.4%)15 (42.9%)20 (57.1%)7.05.001*
Superior hardware11 (21.2%)41 (78.8%)10 (28.6%)25 (71.4%)1.49.454
Authors

The authors are from The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.

The authors have no financial or proprietary interest in the materials presented herein.

Address correspondence to Julianne D. Schmidt, MA, ATC, Department of Exercise and Sport Science, The University of North Carolina at Chapel Hill, 209 Fetzer Hall, CB#8700, NC 27599-8700; e-mail: jtoler@email.unc.edu

10.3928/19425864-20110817-01

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