Faculty Collaboration Database

Influence of knee flexion angle and age on triceps surae muscle activity during heel raises. J Strength Cond Res 2012 Nov;26(11):3124-33

Date

12/23/2011

Pubmed ID

22190157

DOI

10.1519/JSC.0b013e31824435cf

Scopus ID

2-s2.0-84870414816 (requires institutional sign-in at Scopus site)   10 Citations

Abstract

Triceps surae and Achilles tendon injuries are frequent in sports medicine, particularly in middle-aged adults. Muscle imbalances and weakness are suggested to be involved in the etiology of these conditions, with heel-raise testing often used to assess and treat triceps surae (TS) injuries. Although heel raises are recommended with the knee straight for gastrocnemius and bent for soleus (SOL), the extent of muscle selectivity in these positions is not clear. This study aimed to determine the influence of knee angle and age on TS muscle activity during heel raises. Forty-eight healthy men and women were recruited from a younger-aged (18-25 years) and middle-aged (35-45 years) population. All the subjects performed unilateral heel raises in 0° and 45° knee flexion (KF). Soleus, gastrocnemius medialis (GM) and gastrocnemius lateralis (GL) surface electromyography signals were processed to compute root-mean-square amplitudes, and data were analyzed using mixed-effects models and stepwise regression. The mean TS activity during heel raises was 23% of maximum voluntary isometric contraction when performed in 0° KF and 21% when in 45°. Amplitudes were significantly different between TS muscles (p < 0.001) and KF angles (p < 0.001), with a significant interaction (p < 0.001). However, the age of the population did not influence the results (p = 0.193). The findings demonstrate that SOL activity was 4% greater when tested in 45° compared with 0° KF and 5% lower in the GM and GL. The results are consistent with the recommended use of heel raises in select knee positions for assessing, training, and rehabilitating the SOL and gastrocnemius muscles; however, the 4-5% documented change in activity might not be enough to significantly influence clinical outcome measures or muscle-specific benefits. Contrary to expectations, TS activity did not distinguish between middle-aged and younger-aged adults, despite the higher injury prevalence in middle age.

Author List

Hébert-Losier K, Schneiders AG, García JA, Sullivan SJ, Simoneau GG

Author

Guy Simoneau PhD Professor in the Physical Therapy department at Marquette University

MESH terms used to index this publication - Major topics in bold

Adolescent
Adult
Age Factors
Ankle Joint
Biomechanical Phenomena
Electromyography
Female
Heel
Humans
Knee Joint
Male
Middle Aged
Movement
Muscle Contraction
Muscle, Skeletal
Regression Analysis
Young Adult