Zhang X, Deng L, Yang Y, Li L, Fu W. Acute shoe effects on Achilles tendon loading in runners with habitual rearfoot strike pattern.
Gait Posture 2020;
82:322-328. [PMID:
33022565 DOI:
10.1016/j.gaitpost.2020.09.027]
[Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 09/09/2020] [Accepted: 09/24/2020] [Indexed: 02/02/2023]
Abstract
OBJECTIVES
Although the overuse injury rate of the Achilles tendon (AT) for running is high, the effect of shoe conditions on AT loading remains unclear. Hence, this study aims to determine the mechanical properties of AT during running under different shoe conditions (minimalist vs. conventional shoes).
DESIGN
This work is a controlled laboratory study.
METHODS
Sixteen healthy male rearfoot strike runners were recruited to complete over ground running trials at 3.33 m/s (±5%) under two shoe conditions (minimalist shoes: INOV-8 Bare-XF 210; conventional shoes: NIKE AIR ZOOM PEGASUS 34). Sagittal plane ankle kinematics and ground reaction forces were simultaneously recorded. Ankle joint mechanics (ankle joint angle and moment) and the mechanical properties (peak force, impulse, stress, strain, and their corresponding peak rate) of the AT were calculated.
RESULTS
In comparison with conventional shoes, wearing minimalist shoes showed significant changes (p < 0.05): (1) decreased strike angle (48.92 ± 9.01 vs. 41.04 ± 8.69°); (2) increased ankle moment (2.34 ± 0.44 vs. 2.55 ± 0.46 Nm/kg); (3) increased peak AT force (5.85 ± 1.22 vs. 6.24 ± 1.13 BW), AT force impulse (0.65 ± 0.13 vs. 0.70 ± 0.13 BW·s), peak AT loading rate (109.94 ± 9.33 vs. 118.84 ± 26.62 BW/s), and average loading rate (48.42 ± 15.64 vs. 54.90 ± 17.47 BW/s); (4) decreased time to peak AT force (126.31 ± 20.68 vs. 117.77 ± 17.62 ms); (5) increased AT stress (66.96 ± 14.59 vs. 71.89 ± 14.74 MPa), strain (8.19 ± 1.77 vs. 8.78 ± 1.80 %), peak AT stress rate (66.96 ± 14.59 vs. 71.89 ± 14.74 MPa/s), and strain rate (148.71 ± 48.52 vs. 167.28 ± 42.82 %/s).
CONCLUSION
Increased AT force, loading rate, and stress were observed in runners who habitually wear conventional shoes with rearfoot strike patterns when they wore minimalist shoes. Hence, we recommend a gradual transition to minimalist shoes for runners who habitually wear conventional shoes with rearfoot strike patterns.
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