Clamshells

Muscles worked by the Clamshells

Primary

AbductorsHip AbductorsGlute MediusGluteus Medius

Secondary

GlutesGluteus Maximus

Also called: hip abductors, outer thigh, abductor muscles, glute med, gluteus medius, side glute.

Equipment

No equipment — this is a bodyweight exercise.

How to do the Clamshells

1. Lie on your side with knees bent and stacked on top of each other.
2. Keep your feet together and hips stacked.
3. Open your top knee toward the ceiling without rotating your hips.
4. Squeeze your outer glute at the top.
5. Lower under control. Complete reps on one side, then switch.

Form tips

• Place a hand on your top hip to check for unwanted rolling.
• Keep the movement small and controlled rather than forcing the knee high.
• Rest your head on your lower arm to keep your spine neutral.

At a glance

Clamshells in German & Spanish

Descriptions, instructions and tips ship in all three languages in the JSON.

Related exercises

• Machine Hip Abduction
• Side-Lying Hip Abduction
• Banded IT-Band Stretch
• Barbell Hip Thrust

Exercise data (JSON)

The record below is exactly what exercises.json ships for this exercise — names, descriptions, instructions and tips in English, German and Spanish.

{
  "id": "clamshells",
  "name_en": "Clamshells",
  "name_de": "Clamshells",
  "name_es": "Almejas",
  "description_en": "A side-lying hip exercise opening the top knee against gravity to activate the gluteus medius.",
  "description_de": "Eine Übung in Seitenlage mit angewinkelten Beinen, bei der das obere Knie angehoben wird, um die Hüftabduktoren zu kräftigen.",
  "description_es": "Un ejercicio de abducción de cadera, realizado tumbado de lado, que activa el glúteo medio sin material adicional.",
  "category": "strength",
  "force_type": "push",
  "mechanic": "compound",
  "difficulty": "intermediate",
  "body_part": "upper_legs",
  "primary_muscles": [
    "abductors",
    "gluteus_medius"
  ],
  "secondary_muscles": [
    "gluteus_maximus"
  ],
  "goals": [
    "hypertrophy",
    "strength"
  ],
  "tags": [
    "knee_safe",
    "shoulder_safe",
    "no_axial_load",
    "lower_back_safe"
  ],
  "variation_group": "hip-abduction",
  "is_unilateral": false,
  "is_bodyweight": true,
  "instructions_en": [
    "Lie on your side with knees bent and stacked on top of each other.",
    "Keep your feet together and hips stacked.",
    "Open your top knee toward the ceiling without rotating your hips.",
    "Squeeze your outer glute at the top.",
    "Lower under control. Complete reps on one side, then switch."
  ],
  "instructions_de": [
    "Leg dich auf die Seite, Knie gebeugt und übereinander gestapelt.",
    "Halte die Füße zusammen und die Hüfte gerade übereinander.",
    "Öffne das obere Knie Richtung Decke, ohne die Hüfte zu drehen.",
    "Spanne den seitlichen Gesäßmuskel oben an.",
    "Senke kontrolliert ab. Führe alle Wiederholungen auf einer Seite durch, dann wechseln."
  ],
  "instructions_es": [
    "Túmbate de lado con las rodillas dobladas y apiladas una sobre la otra.",
    "Mantén los pies juntos y las caderas alineadas.",
    "Abre la rodilla superior hacia el techo sin rotar las caderas.",
    "Aprieta el glúteo externo en la posición superior.",
    "Baja de forma controlada. Completa las repeticiones de un lado y luego cambia."
  ],
  "tips_en": [
    "Place a hand on your top hip to check for unwanted rolling.",
    "Keep the movement small and controlled rather than forcing the knee high.",
    "Rest your head on your lower arm to keep your spine neutral."
  ],
  "tips_de": [
    "Lege die obere Hand auf die Hüfte, um Ausweichbewegungen zu spüren.",
    "Öffne das Knie nur so weit, wie das Becken stabil bleibt.",
    "Spanne den Rumpf an, damit der Oberkörper ruhig liegen bleibt."
  ],
  "tips_es": [
    "Sube la rodilla solo hasta donde la pelvis no se mueva.",
    "Hazlo lento y controlado para notar bien el glúteo medio.",
    "Exhala al abrir la rodilla y mantén el abdomen activo."
  ],
  "met": 5.0,
  "images": {
    "flat": {
      "start": "images/flat/clamshells-start.webp",
      "peak": "images/flat/clamshells-peak.webp"
    }
  }
}

Fetch just this exercise

const { exercises } = await fetch(
  "https://exercise-dataset.com/exercises.json"
).then(r => r.json());
const ex = exercises.find(e => e.id === "clamshells");

Free for personal and commercial in-app use with attribution (“Exercise data by RepDB”) — see the license and ready-made attribution snippets. Redistributing the data as a dataset or API is not permitted.