Modifiers matching stiffness:

• muscular,

Simple categories matching muscular:

• vessel,
• joint,
• tissue,
• pain,
• activity,
• work,
• sac,
• symptom,
• lameness,
• part,
• group,
• stiffness,
• disorder,
• organs,
• ache,
• structure,
• dystrophy,
• pathology,
• discomfort,
• exertion,
• area,
• disease,
• phenomenon,
• condition,
• control,
• action,
• region,
• effort,
• movement,
• spasm,
• organ,
• problem,
• dog,
• artery,
• abnormality,