My player keeps tipping over when he comes into the scene, how do I stop this from happening?

// Player

    func createPlayer() {
        let playerTexture = SKTexture(imageNamed: "player-1")
        player = SKSpriteNode(texture: playerTexture)
        player.zPosition = 10
        player.position = CGPoint(x: frame.width / 6, y: frame.height * 0.75)
        player.physicsBody?.allowsRotation = false

        addChild(player)

        // Sets up pixel-perfect physics on the player
        player.physicsBody = SKPhysicsBody(texture: playerTexture, size: playerTexture.size())

        // Makes SpriteKit tell you any time the player collides with something
        player.physicsBody!.contactTestBitMask = player.physicsBody!.collisionBitMask

        // Makes the player respond to physics
        player.physicsBody?.isDynamic = true

        //player.physicsBody?.collisionBitMask = 0

        let frame2 = SKTexture(imageNamed: "player-2")
        let frame3 = SKTexture(imageNamed: "player-3")
        let frame4 = SKTexture(imageNamed: "player-4")
        let frame5 = SKTexture(imageNamed: "player-5")
        let frame6 = SKTexture(imageNamed: "player-6")
        let frame7 = SKTexture(imageNamed: "player-7")
        let frame8 = SKTexture(imageNamed: "player-8")
        let frame9 = SKTexture(imageNamed: "player-9")
        let frame10 = SKTexture(imageNamed: "player-10")
        //let frame11 = SKTexture(imageNamed: "player-11")
        //let frame12 = SKTexture(imageNamed: "player-12")

        let animation = SKAction.animate(with: [playerTexture, frame2, frame3, frame4, frame5, frame6, frame7, frame8, frame9, frame10,], timePerFrame: 0.1)
        let runForever = SKAction.repeatForever(animation)

        player.run(runForever)
        }