public void makeMuscles() {
		Mass one;
		Mass two;
		double restLength;
		double constant;
		double amplitude;

		NodeList nodes = myDoc.getElementsByTagName(MUSC);
		for (int i = 0; i < nodes.getLength(); i++) {
			restLength = -1;
			constant = 1;

			Node springItem = nodes.item(i);
			NamedNodeMap nodeMap = springItem.getAttributes();

			one = myMassMap.get(nodeMap.getNamedItem(A).getNodeValue());
			two = myMassMap.get(nodeMap.getNamedItem(B).getNodeValue());

			amplitude = Double.parseDouble(nodeMap.getNamedItem(AMP)
					.getNodeValue());

			try {
				restLength = Double.parseDouble(nodeMap.getNamedItem(REST)
						.getNodeValue());
			} catch (Exception e) {
			}

			try {
				constant = Double.parseDouble(nodeMap.getNamedItem(CONST)
						.getNodeValue());
			} catch (Exception e) {
			}

			if (restLength == -1) {
				new Muscle(one, two, amplitude);
			} else {
				new Muscle(one, two, restLength, constant, amplitude);
			}
		}
	}