Effects of Improved Calf Muscle Function on Gait, Balance and Joint Loading in Older Adults

University of Eastern Finland30 enrolled

Overview

This study investigates the role of calf muscle function in gait performance, balance and knee joint loading. Previous studies have linked age-related loss of calf muscle function with impairments in gait performance and balance, and increased loading of the areas of the knee joint that are susceptible to the development of osteoarthritis. In this study, an exercise intervention targeting structural and neural aspects of impaired calf muscle function with ageing is utilized. The intervention lasts 8 weeks and includes either biofeedback training using electromyography to alter muscle activation patterns or a combination of biofeedback training and strength training for the calf muscle to modify calf function during walking. The study will test whether the intervention improves walking speed, reduces the metabolic cost of walking, improves standing balance and reduces knee joint loading.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

NONE

Enrollment

Conditions

Osteoarthritis, Knee Mobility Limitation Accidental Fall

Interventions

Gait retrainingOTHER

Gait retraining using real-time electromyography biofeedback performed once per week for eight weeks. During the gait retraining session the participant is walking on a treadmill while receiving information on calf muscle activation. A single session includes five bouts of walking each lasting for 5 minutes. During the first bout, the participant is receiving feedback (visual and auditive) on soleus muscle activation with the aim to increase it by 20% from their normal walking. During the second bout, the participant is receiving feedback (visual and auditive) on medial gastrocnemius muscle activation with the aim to decrease it by 20% from their normal walking. During the last three bouts, the participant is receiving feedback (visual and auditive) on the soleus to medial gastrocnemius muscle activation ratio with the aim to increase it by 20% from their normal walking. If hitting the target, the aim is increased by 5% for the subsequent bout.

Gait retraining + strength trainingOTHER

Gait retraining using real-time electromyography biofeedback performed once per week and home-based calf muscle strength training performed three times per week for eight weeks. The gait retraining is identical to the one intervention described for the intervention group "Gait retraining". The strength training is performed three times per week except for the first week in which it is performed two times. The session contained a warm-up (3x10 repetitions of two-legged heel raises) and maximal isometric calf muscle contractions. The maximal contractions are performed using a custom device with the ankle in dorsiflexion and the knee flexed by 100-120 degrees. Three sets of 10 repetitions (3-second contraction and 3-second rest) are performed with both legs and with maximal effort and 1-minute rest between the sets.

Outcomes

Primary Outcomes

Change from baseline in knee joint loading

Change in tibiofemoral compressive loading during walking estimated using musculoskeletal modeling and simulation. Loading is calculated separately for medial and lateral compartments of the tibiofemoral joint.