Associations between Muscle-Tendon Morphology and Functional Movements Capacity, Flexibility, and Balance in Older Women

Abstract

Loss of functional movement capacity in older adults is related to adverse changes in musculotendinous morphology, but this relationship is poorly understood. This study examined the associations between musculotendinous morphology and functional movements, flexibility, and balance ability. Ninety-nine older women (66.6 ± 4.6 years, body mass index 23.5 ± 3.3 kg∙m−2) were recruited from Chonburi Province, Thailand. During one 90-min visit, muscle ultrasound imaging of vastus lateralis, biceps femoris, and medial gastrocnemius muscles, and tendon ultrasonography of the Achilles tendon and patellar tendon were performed. Measures were also obtained for the straight leg raise, passive dorsiflexion, balance, and functional tests (Five Times Sit to Stand (5TSTS), Timed Up and Go (TUG), 10-Meter Fast Walk Test (10-MFWT), and 6-Minute Walk Test (6-MWT)). The results specify that functional movement performance correlates most strongly with medial gastrocnemius muscle thickness (5TSTS (r = −0.26), TUG (r = −0.44), 10-MFWT (r = 0.41), and 6-MWT (r = 0.48) all p < 0.05) and that vastus lateralis muscle thickness and medial gastrocnemius muscle thickness correlate positively with balance ability (r = 0.24, 0.34; p < 0.05) and negatively with fear of falling. It appears that muscle mass, rather than other morphological parameters, such as muscle quality or fascicle length, is the main factor affecting the susceptibility of older women to frailty.

Keywords: echo intensity; flexibility; muscle thickness; older adults; physical fitness.

Figure 1

The percentages of explained variance for functional performance variables. (A) 5TSTS performance, (B) TUG performance, (C) 10-MFWT performance, (D) 6-MWT performance. MT, muscle thickness; BF, biceps femoris; MG, medial gastrocnemius; FL₀, resting fascicle length; FES-1, Falls Efficacy Scale-international; 5TSTS, five times sit to stand; TUG, timed up and go; 10-MFWT, 10 min fast walk test; 6-MWT, six minutes walk test.