Effects of Whole-Body Vibration on Lower-Limb Muscle Activity in a Flywheel Half-Squat.

Superimposed vibration produced the largest muscle activation increases in gastrocnemius lateralis and gluteus maximus in male participants.

• In males, GASLAT showed +40.8% increase during eccentric phase and +55.4% during concentric phase at 40 Hz
• GMAX showed +20.1% eccentric and +33.8% concentric increases in males
• Other muscles in males showed 'modest or inconsistent responses'
• Conditions tested included two inertial loads (IL1 = 0.0306 kg·m2 and IL2 = 0.0562 kg·m2) with vibration at 30 and 40 Hz

Female participants exhibited broader neuromuscular facilitation from superimposed vibration compared to males, with larger percentage increases across more muscle groups.

• GMAX in females showed +57.2% eccentric and +56.0% concentric activation increases
• GASLAT in females showed +73.3% eccentric and +80.6% concentric activation increases
• BF showed a notable increase of +27.9% in females
• Quadriceps showed increases up to +24.7% in females
• Females exhibited 'broader facilitation' compared to males whose other muscles showed 'modest or inconsistent responses'

The study examined muscle activation across seven lower-limb muscles during six flywheel squat conditions combining two inertial loads with and without two vibration frequencies.

• Thirty physically active participants were tested (15 males and 15 females)
• Muscles examined: rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM), biceps femoris (BF), gluteus maximus (GMAX), gastrocnemius medialis (GASMED), and gastrocnemius lateralis (GASLAT)
• Half-squats were performed at 90° knee flexion on a flywheel device
• Two inertial loads used: IL1 = 0.0306 kg·m2 and IL2 = 0.0562 kg·m2
• Vibration frequencies of 30 Hz and 40 Hz were tested alongside no-vibration conditions

Vibration at 30–40 Hz substantially amplified posterior-chain and ankle stabilizer activation without producing uniform effects across all muscles.

• Posterior-chain muscles (GMAX, BF) and ankle stabilizers (GASLAT, GASMED) showed the most pronounced responses
• Vibration effects were described as not uniform across all muscles
• Effects were also described as gender-specific in addition to muscle-specific
• The authors concluded that vibration effects were 'particularly' pronounced 'in females'

The authors concluded that combining whole-body vibration with inertial resistance training may optimize neuromuscular recruitment with applications in athletic performance and rehabilitation.

• Potential applications were identified specifically in athletic performance and rehabilitation contexts
• The authors noted particular relevance 'especially in females' given the greater activation responses observed
• The combination was described as able to 'optimize neuromuscular recruitment'
• Strength and conditioning professionals were identified as the target audience for these findings