Department of Orthopedic Surgery and Institute for Rare Diseases, Korea University Medical Center, Guro Hospital, Seoul, Republic of Korea.
Department of Physical Medicine & Rehabilitation, Korea University Medical Center, Guro Hospital, Seoul, Republic of Korea; Motion Analysis Center, Korea University Medical Center, Guro Hospital, Seoul, Republic of Korea.
Gait Posture. 2021 Feb;84:79-86. doi: 10.1016/j.gaitpost.2020.11.018. Epub 2020 Nov 18.
Limb length discrepancy (LLD) is common and is associated with musculoskeletal disorders. Selection of adaptation strategies, the side more susceptible to complications, and the relationships between LLD magnitude and musculoskeletal complications are unclear. To elucidate these ambiguities, studies on gait parameters in LLD have been conducted. However, studies on inter-limb difference of mechanical work in LLD are rare.
To investigate whether inter-limb differences in mechanical work in LLD and the relationship between LLD magnitude and mechanical work performed by each lower limb are significant.
Thirty-seven participants with LLD and without neuromuscular disorders disturbing normal gait were included. Three-dimensional motion analysis was conducted to obtain data on mechanical work, including joint work and the individual limb method (ILM) work. Mechanical work performed by the longer and shorter limbs was compared using paired t-test. Relationships between LLD and mechanical work were investigated using correlation and multiple regression analyses in both limbs. Eighteen participants had LLD > 20 mm, large group (LG), and 19 had LLD < 20 mm, small group (SG). Data exploration was conducted for the effect of LLD severity (LG vs. SG) on mechanical work.
LLD showed significant inter-limb difference of mechanical work and negative correlations with positive and negative ILM work performed by the shorter limb. The shorter limb in SG performed significantly larger positive ILM work than the longer limb, whereas the longer limb in LG performed significantly larger negative ILM work than the shorter limb.
LLD showed inter-limb difference of ILM work and different adaptation strategies between LG and SG. These differences attribute to the decrease in ILM work performed by the shorter limb with the increase in LLD. Mechanical work including ILM work should be included in future studies to prevent complications and development of treatment methods for LLD.
肢体长度差异（LLD）很常见，与肌肉骨骼疾病有关。适应策略的选择、更容易发生并发症的一侧以及 LLD 幅度与肌肉骨骼并发症之间的关系尚不清楚。为了阐明这些模糊之处，已经对 LLD 中的步态参数进行了研究。然而，关于 LLD 中机械功的肢体间差异的研究很少。
研究 LLD 中机械功的肢体间差异以及 LLD 幅度与每条下肢所做机械功之间的关系是否显著。
纳入 37 名患有 LLD 且无神经肌肉疾病干扰正常步态的参与者。进行三维运动分析以获取机械功数据，包括关节功和个体肢体方法（ILM）功。使用配对 t 检验比较较长和较短肢体的机械功。使用相关和多元回归分析在两个肢体中研究 LLD 与机械功之间的关系。18 名参与者 LLD>20mm，为大组（LG），19 名参与者 LLD<20mm，为小组（SG）。进行数据探索以研究 LLD 严重程度（LG 与 SG）对机械功的影响。
LLD 显示出机械功的明显肢体间差异，与较短肢体的正向和负向 ILM 功呈负相关。SG 中的较短肢体的正向 ILM 功明显大于较长肢体，而 LG 中的较长肢体的负向 ILM 功明显大于较短肢体。
LLD 显示出 ILM 功的肢体间差异以及 LG 和 SG 之间的不同适应策略。这些差异归因于 LLD 增加导致较短肢体的 ILM 功减少。未来的研究应包括机械功，包括 ILM 功，以预防 LLD 的并发症和开发治疗方法。
