Ankle joint angle and lower leg musculotendinous unit responses to cryotherapy

Akehi, K, Long, BC, Warren, AJ, and Goad, CL. Ankle joint angle and lower leg musculotendinous unit responses to cryotherapy. J Strength Cond Res 30(9): 2482-2492, 2016 - The use of cold application has been debated for its influence on joint range of motion (ROM) and stiffness. The purpose of this study was to determine whether a 30-minute ice bag application to the plantarflexor muscles or ankle influences passive ankle dorsiflexion ROM and lower leg musculotendinous stiffness (MTS). Thirty-five recreationally active college-aged individuals with no history of lower leg injury 6 months before data collection volunteered. On each testing day, we measured maximum passive ankle dorsiflexion ROM (°) and plantarflexor torque (N·m) on an isokinetic dynamometer to calculate the passive plantarflexor MTS (N·m per degree) at 4 joint angles before, during, and after a treatment. Surface electromyography amplitudes (V), and skin surface and ambient air temperature (°C) were also measured. Subjects received an ice bag to the posterior lower leg, ankle joint, or nothing for 30 minutes in different days. Ice bag application to the lower leg and ankle did not influence passive ROM (F_(12,396) 0.67, p 0.78). Passive torque increased after ice bag application to the lower leg (F_(12,396) 2.21, p 0.011). Passive MTS at the initial joint angle increased after ice bag application to the lower leg (F_(12,396) 2.14, p 0.014) but not at the other joint angles (p > 0.05). Surface electromyography amplitudes for gastrocnemius and soleus muscles increased after ice application to the lower leg (F (2,66) 5.61, p 0.006; F_(12,396) 3.60, p < 0.001). Ice bag application to the lower leg and ankle joint does not alter passive dorsiflexion ROM but increases passive ankle plantarflexor torque in addition to passive ankle plantarflexor MTS at the initial joint angle.