Browsing by Author "Becker, James N."

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Biomechanical Factors Associated With Achilles Tendinopathy and Medial Tibial Stress Syndrome in Runners
(2017-06) Becker, James N.; James, Stanley; Wayner, Robert; Osternig, Louis; Chou, Li-Shan
BACKGROUND: There is disagreement in the literature regarding whether the excessive excursion or velocity of rearfoot eversion is related to the development of 2 common running injuries: Achilles tendinopathy (AT) and medial tibial stress syndrome (MTSS). An alternative hypothesis suggests that the duration of rearfoot eversion may be an important factor. However, the duration of eversion has received relatively little attention in the biomechanics literature. HYPOTHESIS: Runners with AT or MTSS will demonstrate a longer duration of eversion but not greater excursion or velocity of eversion compared with healthy controls. STUDY DESIGN: Controlled laboratory study. METHODS: Forty-two runners participated in this study (13 with AT, 8 with MTSS, and 21 matched controls). Participants were evaluated for lower extremity alignment and flexibility, after which a 3-dimensional kinematic and kinetic running gait analysis was performed. Differences between the 2 injuries and between injured and control participants were evaluated for flexibility and alignment, rearfoot kinematics, and 3 ground-reaction force metrics. Binary logistic regression was used to evaluate which variables best predicted membership in the injured group. RESULTS: Injured participants, compared with controls, demonstrated higher standing tibia varus angles (8.67Â° Â± 1.79Â° vs 6.76Â° Â± 1.75Â°, respectively; P = .002), reduced static dorsiflexion range of motion (6.14Â° Â± 5.04Â° vs 11.19Â° Â± 5.10Â°, respectively; P = .002), more rearfoot eversion at heel-off (-6.47Â° Â± 5.58Â° vs 1.07Â° Â± 2.26Â°, respectively; P < .001), and a longer duration of eversion (86.02% Â± 15.65% stance vs 59.12% Â± 16.50% stance, respectively; P < .001). There were no differences in the excursion or velocity of eversion. The logistic regression (Ï‡2 = 20.84, P < .001) revealed that every 1% increase in the duration of eversion during the stance phase increased the odds of being in the injured group by 1.08 (95% CI, 1.023-1.141; P = .006). CONCLUSION: Compared with healthy controls, runners currently symptomatic with AT or MTSS have a longer duration of eversion but not greater excursion or velocity of eversion. CLINICAL RELEVANCE: Static measures of the tibia varus angle and dorsiflexion range of motion, along with dynamic measures of the duration of eversion, may be useful for identifying runners at risk of sustaining AT or MTSS.
Joint coordination when running in minimalist, neutral, and ultra-cushioning shoes
(2020-03) Borgia, Brianne; Freedman Silvernail, Julia; Becker, James N.
Ultra-cushioning (ULTRA) shoes are new to the running shoe market. Several studies have evaluated kinematics and kinetics while running in ULTRA shoes, however it remains unknown how such shoes influence joint coordination. Therefore, the purpose of this study was to evaluate lower extremity coordination and coordination variability when running in minimalist (MIN), traditional (NEUT) and ULTRA shoes. Fifteen runners ran for ten minutes in each shoe type. Coordination patterns and coordination variability were assessed for rearfoot-tibia, rearfoot-knee, and tibia-knee couplings using a modified vector coding method during early, mid, and late stance periods. During late stance ULTRA shoes resulted in more antiphase coordination than MIN (p =.036) or NEUT (p =.047) shoes and less in-phase coordination than MIN (p =.048) or NEUT (p =.013) shoes. During late stance there was also more proximal phase rearfoot-knee coordination in ULTRA shoes than in either MIN (p =.039) or NEUT (p =.005) shoes and less in-phase coordination in ULTRA shoes than in NEUT shoes (p =.006). There were no differences in coordination variability between shoes during any phase. The differences in coordination may have implications for tissue loading and injury development when running in ULTRA shoes.
Kinematics and muscle activity when running in partial minimalist, traditional, and maximalist shoes
(2020-02) Becker, James N.; Borgia, Brianne
While several studies have examined kinematic and kinetic differences between maximalist (MAX), traditional (TRAD), or partial minimalist (PMIN) shoes, to date it is unknown how MAX shoes influence muscle activity. This study compared lower extremity kinematics and muscle activity when running in PMIN, TRAD, and MAX shoes. Thirteen participants ran in each shoe while whole body kinematics were recorded using motion capture and electromyography was recorded from seven leg muscles. Differences in kinematics and root mean square amplitudes (RMS) were compared between shoe conditions. There were small differences in sagittal and frontal plane ankle kinematics between shoe conditions, with the MAX shoes resulting in less dorsiflexion at foot strike (p = .002) and less peak dorsiflexion (p < .001), and the PMIN shoes resulting in greater peak eversion (p = .012). Gluteus medius (p.006) and peroneus longus (p = .007) RMS amplitudes were greater in the MAX shoe then the TRAD or PMIN shoes while tibialis anterior RMS amplitudes were higher in the PMIN shoes (p = .005) than either the TRAD or MAX shoes. Consistent with previous findings, these results suggest there are small differences in kinematics when running in these three shoe types. This may partly be explained by the changes in muscle activity, which may be a response in order to maintain a preferred or habitual movement path. Implications for these difference in muscle activity in terms of fatigue or injury remain to be determined.
Quantifying National Biomechanics Day’s Impact on Student Perceptions toward Biomechanics: A Multisite Pilot Study
(Elsevier BV, 2021-12) Monfort, Scott M.; Bigelow, Kimberly E.; Vallabhajosula, Srikant; Evertz, Loribeth Q.; Becker, James N.; Wittstein, Matthew W.; Gannon, Paul; DeVita, Paul
National Biomechanics Day (NBD) is an international celebration of biomechanics that seeks to increase the awareness and appreciation of biomechanics among the high school community. Initial research supports the positive effects of NBD on students’ attitudes toward the field of biomechanics; however, quantitative evidence remains scarce. The purpose of this study was to quantify changes in high school students’ perceptions toward biomechanics after participating in NBD events to better understand the impact of NBD. Data were collected at two locations during the 2019 NBD season. Surveys were collected before and after NBD events for 112 high school students from Montana and North Carolina. Paired pre- versus post-NBD surveys for the aggregate sample population suggest that students perceived biomechanics as more appealing (p = 0.050), exciting (p = 0.007), and important (p = 0.018) following the NBD events. Students did not report a change in whether they could see themselves in a biomechanics-related career (p = 0.49). These findings further support the ability for NBD events to positively impact students’ perceptions toward biomechanics, although opportunities persist to increase student career interest in biomechanics. This paper presents and discusses the study’s results, interpretations, limitations, and implications for future research on biomechanics outreach activities.