Scholarlink

<p>The single leg deadlift (SLD), one of resistance exercises, is widely prescribed to enhance muscular strength and balance due to its inherent unstable, unilateral nature. However, this instability may limit joint mobility and diminish strength training efficacy. This study aimed to investigate the biomechanical effect of surface-induced instability during SLD performance. Thirty healthy adult males performed SLDs under stable surface (flat ground) and unstable surface (foam-pad). Inertial measurement unit (IMU) and surface electromyography (EMG) were employed to assess joint kinematics, such as range of motion (ROM) and joint sway, and muscle activation patterns during stretch-shortening cycle. The unstable surface significantly increases ankle joint sway by 80.00% during the eccentric phase and 99.62% during the concentric phase (<i>p</i> &lt; 0.05). While ankle joint ROM remains unaltered, instability reduces ROM at hip and knee joints by 6.04° and 3.81°, respectively. EMG analyses revealed that surface instability elevated Gluteus Maximus activation during the eccentric phase (13.27%) and Tibialis Anterior activation during both eccentric (6.56%) and concentric (15.21%) phases. Notably, Biceps Femoris activation increases across both phases under unstable conditions. Surface-induced instability during the SLD augments neuromuscular demand, particularly in the balance and stabilizing ankle musculature. However, this instability reduces hip and knee joint mobility, which may compromise the mechanical loading required for strength adaptation. These findings underscore the need for strategic integration of instability in resistance training programs depending on specific performance goals.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Biomechanical analysis of single leg deadlift under the effect of instability

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年6月16日

查看全文
  • Jioun Kim,
  • Youngirl Jeon,
  • Kilho Eom

摘要

The single leg deadlift (SLD), one of resistance exercises, is widely prescribed to enhance muscular strength and balance due to its inherent unstable, unilateral nature. However, this instability may limit joint mobility and diminish strength training efficacy. This study aimed to investigate the biomechanical effect of surface-induced instability during SLD performance. Thirty healthy adult males performed SLDs under stable surface (flat ground) and unstable surface (foam-pad). Inertial measurement unit (IMU) and surface electromyography (EMG) were employed to assess joint kinematics, such as range of motion (ROM) and joint sway, and muscle activation patterns during stretch-shortening cycle. The unstable surface significantly increases ankle joint sway by 80.00% during the eccentric phase and 99.62% during the concentric phase (p < 0.05). While ankle joint ROM remains unaltered, instability reduces ROM at hip and knee joints by 6.04° and 3.81°, respectively. EMG analyses revealed that surface instability elevated Gluteus Maximus activation during the eccentric phase (13.27%) and Tibialis Anterior activation during both eccentric (6.56%) and concentric (15.21%) phases. Notably, Biceps Femoris activation increases across both phases under unstable conditions. Surface-induced instability during the SLD augments neuromuscular demand, particularly in the balance and stabilizing ankle musculature. However, this instability reduces hip and knee joint mobility, which may compromise the mechanical loading required for strength adaptation. These findings underscore the need for strategic integration of instability in resistance training programs depending on specific performance goals.