A Study on the Influence of Varied Load Weights on Human Balance Ability and Lower Limb Biomechanics
OBJECTIVE:This study aims to evaluate the impact of different load weights on human balance ability and lower limb biomechanical parameters,providing insights for weight-bearing training.METHODS:Employing a randomized crossover design,15 healthy male participants(average age:18.93±0.44 years;height:181.20±3.49 cm;weight:74.70±8.20 kg)underwent four dual-foot balance tests with loads of 0 kg,17.5 kg,27.5 kg,and 50 kg.Load was applied using a vest,maintaining relative front-to-back balance.Kinematic and kinetic data were recorded using the Vicon optical motion capture system and AMTI force plates.RESULTS:As the load reached 50 kg(67%BW),balance metrics revealed a significant reduction in participants'balance ability with increasing load(P<0.01);kinematic parameters showed a decrease in dorsiflexion angle at the ankle joints(P<0.001),an increase in extension angle at the knee joints(P<0.001),along with a rise in eversion angle at the right ankle(P<0.05)and adduction angle at the knee(P<0.01);kinetic parameters demonstrated an increase in bending torque at the knee joints(P<0.01),while plantarflexion torque at the right ankle(P<0.001)and bending torque at the hip joint(P<0.01)significantly increased.CONCLUSION:During weight-bearing standing,human balance is compromised,leaning towards relying on knee and ankle joints to maintain postural stability.Daily training should emphasize strengthening the strength of ankle and knee joints.