Dynamic Loading of the Plantar Aponeurosis in Walking

• Published in: Journal of bone and joint surgery. American volume Vol. 86; no. 3; pp. 546 - 552
• Main Authors: Erdemir, Ahmet, Hamel, Andrew J, Fauth, Andrew R, Piazza, Stephen J, Sharkey, Neil A
• Format: Journal Article
• Language: English
• Published: Boston, MA Copyright by The Journal of Bone and Joint Surgery, Incorporated 01.03.2004; Journal of Bone and Joint Surgery Incorporated; Journal of Bone and Joint Surgery AMERICAN VOLUME
• Edition: American volume
• Subjects: Achilles Tendon - physiology; Adult; Aged; Aged, 80 and over; Biological and medical sciences; Body Weight; Cadaver; Calibration; Diseases of the osteoarticular system; Electromyography; Fascia - physiology; Fasciitis - etiology; Female; Fiber Optic Technology; Foot - physiology; Foot Diseases - etiology; Gait - physiology; Humans; Linear Models; Male; Medical sciences; Middle Aged; Models, Biological; Stress, Mechanical; Transducers; Walking - physiology; Weight-Bearing - physiology; Human; Walking; Simulation; Orthopedics; Rheumatology; Plantar aponeurosis; Cadaver; Dynamic load
• ISSN: 0021-9355; 1535-1386
• DOI: 10.2106/00004623-200403000-00013

BackgroundThe plantar aponeurosis is known to be a major contributor to arch support, but its role in transferring Achilles tendon loads to the forefoot remains poorly understood. The goal of this study was to increase our understanding of the function of the plantar aponeurosis during gait. We specifically examined the plantar aponeurosis force pattern and its relationship to Achilles tendon forces during simulations of the stance phase of gait in a cadaver model.MethodsWalking simulations were performed with seven cadaver feet. The movements of the foot and the ground reaction forces during the stance phase were reproduced by prescribing the kinematics of the proximal part of the tibia and applying forces to the tendons of extrinsic foot muscles. A fiberoptic cable was passed through the plantar aponeurosis perpendicular to its loading axis, and raw fiberoptic transducer output, tendon forces applied by the experimental setup, and ground reaction forces were simultaneously recorded during each simulation. A post-experiment calibration related fiberoptic output to plantar aponeurosis force, and linear regression analysis was used to characterize the relationship between Achilles tendon force and plantar aponeurosis tension.ResultsPlantar aponeurosis forces gradually increased during stance and peaked in late stance. Maximum tension averaged 96% ± 36% of body weight. There was a good correlation between plantar aponeurosis tension and Achilles tendon force (r = 0.76).ConclusionsThe plantar aponeurosis transmits large forces between the hindfoot and forefoot during the stance phase of gait. The varying pattern of plantar aponeurosis force and its relationship to Achilles tendon force demonstrates the importance of analyzing the function of the plantar aponeurosis throughout the stance phase of the gait cycle rather than in a static standing position.Clinical RelevanceThe plantar aponeurosis plays an important role in transmitting Achilles tendon forces to the forefoot in the latter part of the stance phase of walking. Surgical procedures that require the release of this structure may disturb this mechanism and thus compromise efficient propulsion.